sailboat hull core repair

• New Sailboats
• Sailboats 21-30ft
• Sailboats 31-35ft
• Sailboats 36-40ft
• Sailboats Over 40ft
• Sailboats Under 21feet
• used_sailboats
• Apps and Computer Programs
• Communications
• Fishfinders
• Handheld Electronics
• Plotters MFDS Rradar
• Wind, Speed & Depth Instruments
• Anchoring Mooring
• Running Rigging
• Sails Canvas
• Standing Rigging
• Diesel Engines
• Off Grid Energy
• Cleaning Waxing
• DIY Projects
• Repair, Tools & Materials
• Spare Parts
• Tools & Gadgets
• Cabin Comfort
• Ventilation
• Footwear Apparel
• Foul Weather Gear
• Mailport & PS Advisor
• Inside Practical Sailor Blog
• Activate My Web Access
• Reset Password
• Pay My Bill
• Customer Service

• Free Newsletter
• Give a Gift

How to Sell Your Boat

Cal 2-46: A Venerable Lapworth Design Brought Up to Date

Rhumb Lines: Show Highlights from Annapolis

Open Transom Pros and Cons

Leaping Into Lithium

The Importance of Sea State in Weather Planning

Do-it-yourself Electrical System Survey and Inspection

Install a Standalone Sounder Without Drilling

Rethinking MOB Prevention

Top-notch Wind Indicators

The Everlasting Multihull Trampoline

In Search of the Snag-free Clew

What’s Involved in Setting Up a Lithium Battery System?

Reducing Engine Room Noise

Breaking Point: What Can Go Wrong With Your Yanmar?

Mildew-resistant Caulks for Boats

Can We Trust Plastic Boat Parts?

Repairing Molded Plastics

Mailport: Marine plywood, fuel additives, through bolt options, winch handle holders

The Day Sailor’s First-Aid Kit

Choosing and Securing Seat Cushions

Cockpit Drains on Race Boats

Rhumb Lines: Livin’ the Wharf Rat Life

Safer Sailing: Add Leg Loops to Your Harness

Resurrecting Slippery Boat Shoes

Tricks and Tips to Forming Do-it-yourself Rigging Terminals

Marine Toilet Maintenance Tips

Learning to Live with Plastic Boat Bits

The Ultimate Guide to Caring for Clear Plastic

• Boat Maintenance

Step-by-Step Deck Core Repair

Last month we looked at the effectiveness of injecting resin to repair damaged core sections (see “ Can Glue Injection Fix Rotten Core ,” PS July 2018. This month we’ll review the more robust repair option—replacing the bad core.

The factory skimped on resin when laying up the internal skin of the anchor locker hatch on our Corsair F-24 test boat. The goal was to save weight, but the result was hundreds of pinholes, which over the course of thousands of warming and cooling cycles, sucked in a substantial volume of humid anchor locker air. The core became damp, bacteria moved in, and the balsa decayed to the consistency of garden mulch. Small wonder the hatch bent noticeably under foot.

Fortunately, the skins had not yet cracked. The other positive was that the hatch could be taken home for renovation, and that makes any job easier.

When repairing deck core, work can proceed from either the interior side or exterior side. Working from the exterior means your repair will need to match surrounding skin, whereas interior work is usually hidden from view.

For deck repairs, working from the outside means that gravity is on your side. The old core doesn’t land on your face as you remove it, and bonding in new core material is straightforward.

Working from the inside requires removing interior liners and modifying your laminating technique. Larger jobs tend to favor working from above, while small jobs go faster from inside. It all depends on geometry. In our case, we just flipped the cover over.

We cut away the skin using delicate, shallow cuts with an angle grinder. A vibrating multi-tool with a carbide blade is handy for small areas. The skin was then peeled back using a dry wall knife and a pair of pliers.

If it is undamaged and you are working from the top side, save this for later reinstallation. It will preserve the non-skid pattern and smooth curvature in the corners. Even when you are careful, thin skins are often destroyed during removal process, which means you’ll have to laminate a new one—something to consider when deciding which side to work from.

Whichever method you choose, be sure to wear gloves while laminating. Change the gloves every 10 minutes or whenever they begin to get sticky; if glass fibers are sticking to your fingers, you need new gloves. Likewise, have a stack of disposable brushes and polyethylene spreaders available.

Cleaning Out Old Core

Some of the old core will fall out, bringing comfort that you are doing the right thing. Some will come out with a scraper. We’ve found a wire cup brush, in either a cordless drill or angle grinder, makes fast work, with less risk of cutting into the second skin than with vigorous use of a scraper or chisel.

You don’t need to remove undamaged core; when it gets really difficult to remove, you’re probably done. We left some core, after determining that it was like new and that we couldn’t remove it without damaging the skin. Allow the panel to dry.

1. A cutting wheel was used to trim the outer laminate to access the core.

Bonding New Core

You can use either polyester or epoxy resin (see Inside PS blog post “ Epoxy Versus Polyester Resin ”). If you’ve worked with neither before, practice on some sample laminates.

Some sections could be solid glass instead of core. Lay those areas up with cloth or possibly Coosa Bluewater 26 (see “ The Multipurpose Core ,” PS February 2020). For cored areas, coat the sections of replacement core with resin thickened with colloidal silica to a peanut butter consistency. Press into place with a grooved laminating roller.

Use lightweight cores for overhead panels. Plywood is not recommended. Marine core is typically scored with kerfs and attached to a scrim backing so that it can follow curves. If the curve is concave, the kerfs will open the blind side, so be certain to apply enough thickened resin to fill these kerfs as they open.

There is no reason to apply core in large sections, since it is scored anyway. Small sections, generally not much bigger than 6 inches square, are easier to manipulate. Cut smaller pieces to fill the larger gaps, and then spread thickened resin over the entire area using a flexible spatula, forcing it into the remaining hair line cracks. Allow to cure.

Use 60-80 grit on an orbital sander (or a disk grinder with a very light touch) to sand the new core smooth. Even if you matched the original core thickness, there will be irregularities resulting from bumps of old resin and angles from the core.

Laminate a replacement skin, matching the original schedule. Several layers of 17-ounce biaxial cloth with ¾-ounce mat attached (1708), followed by a single layer of 6-ounce finish cloth is common on cruising boats. Smaller boats may use only a few layers of 6-ounce finish cloth. Bevel the core edges to a 10:1 taper.

From the Inside

If you are working from the inside on an overhead panel, lay the cloth on a plastic disposable work surface and pre-saturate the fiberglass cloth, using a squeegee and roller, before placing on the ceiling. Some like to do this on a bench outside the boat and carry the sections in on waxed paper.

Don’t attempt to saturate the cloth directly on the surface; the resin will drip all over you and the glass will keep falling off.

Rub the pre-wetted laminate down firmly with gloved hands and a roller until it begins to cure. If applying more than a few layers overhead, allow the initial layers to gel. This prevents the whole mess from falling off in a sticky pile. Allow to cure.

Use vinegar to wipe surrounding areas that were not covered with drop cloths, being careful not to get any on the bond areas.

From the Outside

If you are reusing the old deck skin, carefully grind the core to fit the original skin, test fitting frequently. You will add thickened resin to bond and fill low areas, but there can’t be any high spots and it is best if the fit is very close.

Unlike a new skin, you won’t be able to roll it in for a perfect bond. This is why we dislike this method other than for very small sections. Press the skin in place, weight it down it with sand bags, and hope for the best.

Finishing and Cleanup

If you are working from the inside, all that remains is to grind it reasonably smooth and replace the liner or paint to match. If you worked from the outside, bevel the joints 10:1 with a hand grinder, add fiberglass tape to match the original thickness, and finish with gel coat or paint.

Clean your tools with vinegar. As long as the cure is not too far alone, vinegar stops the chemical reaction and eliminates the stickiness, allowing clean-up with soap, water, and a brush.

PS Technical Editor Drew Frye is the author of “ Circumnavigating the Delmarva—a Guide for the Shoal Draft Sailor ,” available for Kindle through Amazon.

RELATED ARTICLES MORE FROM AUTHOR

Injectadeck has very specific instructions, it looks like they used it like Git’Rot’ against wet wood? That was not a proper demonstration of the process of injectadeck. I have been using it for three years on several boats. The aforementioned product doesn’t work at all nothing can soak into wet wood or stick to its slime. Injectadeck adheres fiberglass layers together very well, displaces water, hardens in a void.

(Inject-a-Deck was reviewed in “Can Glue Injection Fix a Rotten Core,” July 2020)

Inject-a-Deck can work. There is no question it can firm up a mushy deck and that it is much easier to use than other methods. But we tested it a number of times, in several ways (wet and dry) and concluded that other products were stronger and better suited limited repairs and areas where great strength was required. In fact, we warmed up to the idea that injecting epoxy and Git-Rot is probably not the best method for larger areas of extensive damamge or rot, that the repair materials does not need to be strong like epoxy, only as strong as the original core, and that foaming products, including the original Gorilla Glue, have considerable advantages.

The best repair method is core replacement, but even that method must be approached circumspectly. We recently reviewed a “professional” repair to a PS test boat and found that the contractor had made critical errors, resulting in a repair that was far weaker than what he started with. He hid his tracks well enough that any surveyor could miss the hidden damamge. The result was a sudden failure of the core repair underway. * He reused the original skins by gluing and fairing the edges together, without scarfing in reinforcing lamination. Invisible joints that were very weak. * Cut through critical carbon fiber reinforcements buried within the laminate and did not replaced them. You never know what is inside the deck, and it apparently did not concern him when he got black sawdust, or when he pealed the deck up and saw the carbon plate.

So injecting foam, such as Inject-a-Deck can fall within the “do no harm” philosophy. You won’t hurt anything. It would have been much better, in this case, if the contractor had just injected foam, rather than cut through good laminate he was not committed to properly replacing. Sometimes you don’t know what you are getting into.

Bacteria do not cause core decay. The statement: “The core became damp, bacteria moved in, and the balsa decayed to the consistency of garden mulch.” is misleading because 1) the damage is caused by fungi, not bacteria, and 2) the fungal spores have inhabited the balsa ever since it was changed from being a tree to being small blocks. The spores are patiently waiting for the substrate to become damp to the degree that they can become active.

Good point on the fungi, although that is only true to a point. Rot results from a mixed community of bacteria and fungi, the fungi being more active in the presence of oxygen and during the initiation of rot, and the bacteria becoming more prevalent and active in anaerobic conditions (prevalent in cores) and as the core gradually becomes mulch. But yes, most of the damage is caused by fungi. I took too much literary license, and I knew better. In the end… wood rots. The distinction is mostly relevant when choosing a rot-preventative.

A good read. I’ve done everything from below with Vinylester resin. Of course, you need an excellent full facemask with the right cartridges. Good to know about the “professional” repair mentioned in the above comment. I’ve been “peg boarding” from the inside to dry out the core which did dry quite well with heat lamps (and a temperature gun to not get over 110 degrees). However, if the fiberglass flexed when pushing the drill to drill the hole, I just peeled that area and replaced the core. This winter I will work on the doghouse and this method of looking for some flex won’t work since the interior doghouse glass is thicker. Not sure what I will do.

The softening temperature of vinyl cores is about 190F and epoxy, gelcoat, and vinylester are are a bit higher than that. I would think 150F would be a safe temperature for drying core. I’m sure decks pass 110F in the sun all the time!

Drew I agree, and it’s good to know what you just wrote. And to your point on a hot sunny day in late August here in RI, in the afternoon, the deck was 116F on my temp. gun. The boat I’m working on came from Lake Lanier, Georgia, I’m sure it hit 110 air temp…

LEAVE A REPLY Cancel reply

Log in to leave a comment

Latest Videos

Island Packet 370: What You Should Know | Boat Review

How To Make Starlink Better On Your Boat | Interview

Catalina 380: What You Should Know | Boat Review

• Privacy Policy
• Do Not Sell My Personal Information
• Online Account Activation
• Privacy Manager

Building, restoration, and repair with epoxy

Replacing Damaged Balsa Core

By  bruce niederer — gbi technical advisor.

Above: Surprisingly, much of the damaged balsa core on TRIPLE THREAT was well bonded to the glass skin, as it was to this section of skin around the chainplate. The bad core that didn’t come out with the glass skin was removed with a chisel.

I love my boat. I love to spend time with it-sailing it, working on it, improving it.

I think I need my head examined.

Seriously, there’s got to be something wrong with me! I actually expected that applying a new non-skid deck to TRIPLE THREAT, our 1981 Pearson Flyer, would be a fairly straightforward project. I always think like that before I get started. One would think I might know better by now, but that type of learning apparently requires some protein sequence that’s missing from my DNA.

I started the project by removing all the hardware from the deck-winches, cleats, instruments, lights, sail tracks-everything. This included the old teak toe rails, which I would replace with extruded black anodized aluminum. My apologies to wooden boat enthusiasts, but since I primarily race our boat, maintaining wood trim is time wasted for me.

After removing everything, I planned to apply the hardware bonding techniques described in the WEST SYSTEM® User Manual and repair manuals. Hardware bonding involves drilling all the existing holes oversized. These holes then get filled with thickened epoxy and the proper sized hole is re-drilled through the center of the epoxy when the hardware is ready to be remounted. Doing this would be a good way to protect the balsa core from moisture damage.

Before removing the hardware, it looked like a straightforward project.

As I started drilling the oversize holes, my project expectations headed south. There are tracks for the #3 Jib just behind the chainplates, and drilling these holes oversize revealed that the balsa wood coming out was black and wet. This is bad. When I used another technique where a bent nail or Allen wrench is mounted in a drill motor and used to ream out more damaged balsa core material than just the diameter of the hole, water actually splashed out on deck.

#@*%! This was worse. I found the same condition where the middle reaching track for the #1 Genoa is mounted (below). So now, my new non-skid deck replacement would have to include removing and replacing the bad core—on both sides of the boat, of course.

The damaged balsa core began to be revealed when the hardware was removed.

Replacing the damaged balsa core involves removing the fiberglass skin to expose the core. This can be done either from the topside or below deck. In my case, since the deck was getting new non-skid anyway, the repair would be easier from the topside. Using a circular saw, shallow cuts were made just deep enough to cut through the top skin to open up the damaged area once the skin was removed. A series of cuts were needed, enlarging the area incrementally until good core was reached. The bad core that didn’t come out with the glass skin was removed with a chisel.

It may seem odd that rotten, wet balsa was still bonded securely enough that it had to be removed with a chisel. Many folks have the misconception that balsa is a poor choice for core material, that it will act like a sponge and disintegrate quickly if water gets to it. This is not the case. End grain balsa retains a high percentage of its compression strength and structural integrity for a surprisingly long time after it gets wet exactly because of the grain orientation. Water soaks in much more slowly perpendicular to the grain than it does with the grain-and the end grain is bonded to the skins, so it’s inaccessible. There was no softness in the deck or any indication of the core damage in the deck while the boat was in use last season. Eventually, there would have been, but since the boat is 20 years old, I was very impressed with how well the balsa performed over the years.

Yes, balsa core is heavier than foam, but foam cores have their own weaknesses to be dealt with, and it’s wise to replace whatever core was originally used with the same material. Assuming the skins are the same, a balsa core laminate would be stiffer than a foam core laminate due to balsa’s higher density and shear modulus. Also, according to the Forest Products Laboratory ratings of numerous wood species regarding rot resistance, balsa has the same rating as okoume and meranti: mildly resistant. Okoume and meranti are widely considered a good choice for marine applications, especially when properly coated and installed. So, application and technique are the key factors in using any mildly resistant species of wood, balsa included.

The exposed openings were prepared for repair after the damaged balsa core was removed. A 12:1 bevel was sanded into the fiberglass deck skin around the openings.

After the damaged areas were defined and the bad core removed, the exposed openings needed to be prepared for the repair (above). First, the inside of the exposed bottom skin was sanded with a palm sander and 80-grit paper to clean and level the surface that the new core would be bonded to. Then a smooth and uniform 12:1 bevel was sanded in the fiberglass deck skin around the openings with an orbital sander. Since the skin was 1/8″ thick, this meant the bevel extended 1½” back from the edge of the cut (below). The 12:1 bevel is necessary to provide an adequate bonding surface when laminating in the skin repair patches. (Refer to Chapter 5 in Fiberglass Boat Repair & Maintenance .)

Since the skin was 1/8″ thick, I needed to grind 1½” back from the edge of the cut to make a 12:1 bevel.

Next, ¾” contour core balsa was cut to fit the openings. The term ‘contour core’ means that the core, whether balsa or another core material, has a series of cuts through it. Typically these cuts run perpendicular to each other along the length and width about 1″ to 1½” apart, forming a grid of blocks that are held together by a loosely woven cloth called scrim. This allows the core to follow curvatures in the deck, whether convex or concave. One problem in using contour core is that the blocks of core will separate to some varying degree in conforming to a curve. The resulting gap must be filled to prevent water migration within the deck or hull. With this in mind, I installed the core using a two-step bonding technique.

The first step was to brush neat (unfilled) WEST SYSTEM® 105 Resin®/ 206 Slow Hardener ® over the entire bonding surface inside the opening. This was necessary because even after sanding, the surface remained somewhat irregular because of the chopped strand fiberglass used to build both the upper and lower deck skins. The neat epoxy flows to better fill this fairly level but uneven surface.

The next step was to thicken 105/206 with 407 Low-Density Filler to a consistency slightly thicker than mayonnaise. With an 809 Notched Spreader , a small amount of this “core bedding” mixture was applied around the edges of the repair against the existing core; more was spread out over the neat, uncured epoxy already brushed on the area. The core was then draped over a 10″ diameter PVC tube. Then core bedding mixture was applied in the cuts between the blocks as they opened, both in the 0° and 90° directions, when the tube was rolled. Then the filled core was fit in place and compressed down, squeezing out any excess bedding mixture. Finally, the repair area was cleaned up, all excess bedding mixture was removed, and any voids or gaps were filled using a squeegee, taking care to maintain the 12:1 bevel. A layer of release fabric was placed over the repair and worked down with a squeegee, and everything was allowed to cure completely.

The core was fit in place and compressed to squeeze out excess bedding mixture, and any excess bedding mixture was removed.

The density of the core bedding mixture is greater than that of the core. Therefore, care should be taken to avoid filling too large an area with bedding mixture. This can cause hard spots that affect the designed stress loading patterns of the deck structure or exotherm if too thick of a layer is applied at one time. One area that was filled with the epoxy bedding mixture was around the chainplates, which are notorious for leaking, and were the primary source of trouble on TRIPLE THREAT as well. A gap was left between the core and the chainplate on all sides, then filled with the core bedding mixture to isolate the new core from any water that may leak along the chainplate in the future (below).

A gap between the chainplate and the new core was filled with a bedding mixture to isolate the core from any water that may leak along the chainplate.

The next step involved cutting fiberglass for the patches and laminating them in place. As mentioned earlier, both the top and bottom fiberglass skin of the deck laminate is completely built using chopped strand construction. This was undoubtedly achieved using a chopper gun, which was and continues to be, widely used in production boat building where polyester or vinyl ester resin systems are used. The thickness of a piece of removed deck skin measured with calipers was approximately 0.14″. Instead of doing the whole repair in chopped strand mat alone, I decided to use Episize™ 738 Biaxial Fabric with mat, which is a 15 oz/yd2, ±45° fabric with an 8 oz chopped strand mat on one side. The main reason was that I could build up the same skin thickness with only two layers of the 738 as opposed to 3-4 layers of chopped strand mat. Measurements indicated that two layers of 738 would make the repair slightly lower than the surface of the surrounding deck. This depression would eventually get filled and sanded.

The repair patch technique mentioned starts with the 12:1 bevel that was ground before the core went in. Then, two pieces of 738 glass were cut to shape for each repair area. The bottom, or first piece in, got cut so that it fits about ½” smaller than the outer edge of the bevel around the circumference of the repair. The top piece was cut so that it was about 1″-1½” smaller around the same circumference. Using WEST SYSTEM® 105/206 and a plastic spreader, the two patches were laminated into each repair area, the larger piece going in first followed by the smaller one (below). We are very confident based on testing done at GBI that this repair technique (described in detail in Chapter 4 Fiberglass Boat Repair & Maintenance ) will produce the strongest repair possible. Once again, 879 Release Fabric was used to firmly squeegee the repair laminate in place to compact the fibers and create a no-prep surface for fairing.

With the larger piece of fabric going into the repair area first, followed by the smaller one, only the edges of the fabric are abraded when the repair is cured and sanded.

Once the epoxy cured for a few days, the release fabric was removed. Any rough edges or high spots around the circumference of the repairs were sanded off with an orbital sander. Then a fairing mixture of 105/206 with 407 Low-Density Filler was prepared to a consistency of peanut butter. The higher the percentage of 407, the easier the sanding would be. I made a special tool using an old heavy mainsail batten mounted to a piece of wood so that half the batten was off the wood (below). The tool was long enough to span beyond the length of the long repair. The areas that needed filling were slightly overfilled with the fairing mixture using a squeegee; then, the batten tool was used like a long spreader to smooth and scrape off excess mixture. This was allowed to cure a couple of days. Then a 4′ longboard (long sanding block) was used to sand the filled patches. High and low spots were identified, more filler was applied where needed, and the repair was sanded with the longboard again. Once the repaired area was smooth and fair with the deck, a neat coat of 105/206 was rolled over the sanded 407 surface to fill any porosity and to ready the surface for painting.

I used the batten tool like a long spreader to scrape off excess mixture.

After all this, I was finally back to where I started. Having replaced the damaged balsa core, I was ready to properly reinstall the hardware to avoid more damage and get back to applying a new non-skid surface to the deck (below). In the next issue of Epoxyworks , I describe the details of that portion of the project . I should be nearly done by then.

After replacing the damaged balsa core, I was finally back to where I started-ready to start applying new non-skid surface.

• Forums New posts Unanswered threads Register Top Posts Email
• What's new New posts New Posts (legacy) Latest activity New media
• Media New media New comments
• Boat Info Downloads Weekly Quiz Topic FAQ 10000boatnames.com
• Classifieds Sell Your Boat Used Gear for Sale
• Parts General Marine Parts Hunter Beneteau Catalina MacGregor Oday
• Help Terms of Use Monday Mail Subscribe Monday Mail Unsubscribe

Wet HULL Core Repair

• Thread starter RobC222
• Start date May 31, 2010
• Forums for All Owners
• Ask All Sailors

Discovered this spring wet core in lower half of the transom in in the starboard side hull from the transom forward to the keel, from the water line down to the centerline. Likely source is exhaust tube and engine water inlet. Core samples indicate balsa is wet, but not yet rotted. Balsa came out normal color (not black), saturated with water. I have seen the info on this site and related blogs about recoring. With this extensive an area (at least 100 sqft), a professional recoring is not possible given my limited financial commitment to the boat. Likewise, I am not in a position to do it myself. Ideally, I would like to sell to someone with the time/skill/money, but, in lieu of that, I am seeking alternative methods to repair other than recoring. Is it possible to open the core to the air by drilling a grid of holes thru the outer skin, and allowing to dry over a winter? Or drill from the inside, and run a humidifier for several months to dry out the core?? Any ideas you have heard of, or leads to sites/blogs where project like this have been completed would be welcome.  

Hermit Scott

You have a cored hull BELOW the waterline? Did you use a moisture meter to determine that the core is wet in all of that area? How accessible is the inside of the hull in the area that has the wet core?  

That is pretty much a dead boat  

tommays said: That is pretty much a dead boat Click to expand

100 Square feet on a 30 foot boat? That is like 8x12 feet or 4x25 feet or 10 feet square. Or 3-4'x8' sheets of corecell. It will take 5 gallons of core bond and 30 yards each of chopped strand mat and glass cloth Probably 10 gallons of resin. if you can't do the job yourself then get a different boat.  

I hate to say it but it sounds like a death blow to the boat. Even if you could repair it, the economics of repairing it hardly make sense. You might be better of piecing the boat apart and trying to sell them (engine, rigging, sails etc.). Sorry for your loss....  

I think that the material cost for the repair would fall between 2000 and 3000 dollars. The special handling needs for the work may add another 1000. If you had to hire the work done it would break the bank.  

• This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. By continuing to use this site, you are consenting to our use of cookies. Accept Learn more…

• Boat Accessories
• Where to Buy

Special until March 31st: 40% off Teak Deck Sealant for the month of March. Use Code MAR24 at checkout. *restrictions apply

Free ground shipping in the Continental US for any orders over $150!

Sailboat Hull Repair Guide...

Sailboat hull repair guide.

A dent or hole in your sailboat’s hull can feel like damage to the entire boat. But if your hull is made from fiberglass, you may have more options than you initially thought. We put together this sailboat hull repair guide to help!

Step One: Preparation

Liquid LifeSeal® Sealant 5.2 fl. oz. Clear

Stainless Steel Cleaner 16 fl. oz.

Related blogs, thanksgiving trivia.

Thanksgiving is one of America’s oldest and most loved holidays. Even though the story is steeped in a dark history […]

Detailing Your Boat

There’s nothing better than hitting the water in a beautiful boat. A warm summer day with the sun shining, there’s […]

How To Properly Clean Your Boat Trailer

We all know that cleaning your boat is important to not only keep it looking great, but to also ensure […]

All products proudly made in the usa

Delamination repair

Wet core is a recipe for problems, but repairing the problem is often not as hard as you may think.

Wet core is one of the most common problems you’ll find in boats constructed with a cored-laminate hull or deck, particularly those of a certain age. Although tackling such damage can be a messy job, repair jobs are not as difficult as you might think.

Decks and cabinhouses are often made of cored laminates, typically using balsa, plywood or foam, and all of these are susceptible to water intrusion. It’s a misconception that foam cores are impervious to water intrusion, and even these cores can sustain damage. When moisture enters the core, it starts to degrade, compromising the integrity of the deck or hull.

Balsa is the most common core material because it’s inexpensive, light weight and has very good compressive strength. The downfall of balsa is it absorbs water very quickly and degrades faster than plywood. Plywood is typically used in areas where strength is needed such as around chainplates, mast partners and  winch bases. Decks with foam core may have multiple densities of foam to achieve the strength needed in areas of high load or where weight savings are needed. 

There are a couple ways damage to the core occurs from moisture intrusion. The primary damage is from rot. You can mitigate the damage by carefully sealing every fitting in the area of wet core, which prevents additional moisture from entering, but also seals the core from oxygen, slowing the decomposition process.

This is an important measure to take as soon as you notice an area of soft core. When core material rots it loses its bond to the FRP skins, also known as delamination. 

Laminate with moisture intrusion can also be damaged from the freeze-thaw cycles. When damp laminate is exposed to repeated freezing and thawing and therefore expansion and contraction, delamination occurs.

Regardless of why an area delaminates, when it gets bad enough, it will need to be repaired. 

Severe delamination can sometimes be easy to spot; you’ll literally be able to feel the soft area. But you can check for and identify delaminated areas with a plastic hammer. Tap on suspect areas, listening for a change in tone. Areas in good shape will have a “solid” tone. Delaminated areas will sound dull. If you come across a dull-sounding area tap around it, working out until you get to a solid sound. Mark off the suspect area with chalk or tape. 

If you suspect delamination under a fitting such as a stanchion, try putting some load on it and watch to see if the deck moves. If it does, there is likely delamination.

Moisture meters can also be used to check for delamination, but use caution in interpreting the reading. Moisture meters work by reading how conductive a surface is, but there are many materials that are conductive, including additives in paint and gelcoat. The best way to use a moisture meter is to take comparable readings from similar locations to see of the laminate is more conductive in one location compared to a similar location. 

Once you’ve identified an area of delamination that needs repair, it’s time to get started on what will be a messy project.

1. Start by removing all fittings in the area to be repaired and determine how you want to attack the project. Consideration should be given to ease of working conditions and the final finish of the repaired area. For example, if the area to be repaired  is on the deck, you may want to consider performing the repair from the interior to minimize any gelcoat or paint work on the deck needed to match the existing finish. However, if it is physically impossible to reach the damaged area from the interior, you’ll save time by doing the repair from the outside even if it includes fairing and paint or gelcoat work.

2. Determine the area of the damage to be repaired and mask off and protect as much of the surrounding area as possible. You will need to do a fair amount of grinding and sanding and fiberglass dust gets everywhere. 

3. Using a small oscillating saw, cut the fiber-reinforced plastic skin and remove it. If you are lucky and manage to remove it in one piece you may be able to reuse the skin, but typically it is damaged or needs to be cut out in smaller pieces, which renders it useless. When cutting the outer skin, take care not to cut too far into the laminate and definitely do not cut completely through. Start small and when you remove the outer skin you can then get a good assessment of the condition of the core. From this point, you can start to remove the core and addition outer skin until you get to a point where the core material is dry and the laminate is sound. 

4. Once you have opened up the laminate and cut out all the damaged areas it is time to start prepping the areas for the new core and skin laminate. The core area will need to be sanded to remove any imperfections, contamination or ridges. Grind a scarf joint around the repair area to a width of 12 times the thickness of the skin, about 1.5 inches for 1/8th-inch skin. Go slowly when grinding and sanding to minimize heat buildup on the existing laminate. Heat can damage the resign and could lead to bonding problems later.

5. Once the grinding and sanding is completed it’s time to start assembling the repair. Cut and dry fit the new core material as precisely as possible. A good-fitting core insert will minimize the amount of resin needed. With the new core in place, take a sheet of clear plastic (something like a disposable dropcloth works fine) and lay it over the area. Trace the outline of the area on the plastic and include alignment reference marks. This will be used to cut the fiberglass, carbon fiber or Kevlar to the correct shape.

6. Carefully clean the area of all dust and debris. Mix up enough two-part epoxy or polyester resin to wet out the area where the core will be replaced, including the bottom and the sides. A cheap, disposable paint brush will work fine for this job. If the new core is not a perfect fit, you can add some thickening additive to the resin but keep the consistency as thin as possible to allow it to flow into any voids. Press the core firmly into place and allow it to set up before putting the outer skin laminate on place. You can allow it to fully cure but for the best adhesion it is better to add the final laminate while the resin is not fully cured and somewhat soft. 

7. Using the plastic that you traced the outline of the repair area, cut and place layers of fiberglass, carbon fiber or Kevlar to the desired thickness needed to match the original skin thickness. The first layer should be slightly bigger than the traced outline and each succeeding layer slightly smaller and smaller. The goal is to match the taper of the patch to the scarf that you ground out. At this point, wet out the fiberglass and layer each piece as you go until all layers are fully saturated with resin. Place another piece of plastic over the top and use a squeegee to firmly squeeze out the excess resin. 

8. With a scissors, cut the now wet fiberglass on the traced line making sure you note any reference points. Peel off the plastic on the side where the largest layer is as that will be placed over the core and scarf area first. Once the piece in place, use your squeegee to smooth out the fiberglass. 

9. At this point, you can add additional steps such as a vacuum bag to fully clamp the repair in place. Vacuum bagging compresses the repair as the resin cures, however it requires additional equipment that many DIYers may not have access to. If you have access to peel ply, a thin nylon fabric, you can remove the plastic film and then apply the peel ply and smooth it out. 

10. Once the repair is fully cured per the resin manufacturer’s  instructions, remove the peel ply or plastic and fair and paint or gelcoat as desired. Remount the hardware, making sure to bed it properly using a marine-type sealant/adhesive such as 3M 4000 or Sikaflex and go sailing.

Also in Technique

• Winch servicing
• Repairing delaminated core
• Splicing Dyneema
• DIY custom bug screens
• Anchoring and mooring a catamaran
• Co-owning a boat
• Installing a steering wheel
• Helming skills
• Captain your own charter
• Asymmetric spinnaker skills

Also from Richard Reichelsdorfer

• Docking under power
• Installing a new battery system
• Powerful passagemaker

everythingaboutboats.org

Everything about boats – the ultimate reference resource for boaters.

Sailboat Hull and Deck Repair by Don Casey

PATH:  Contents  » Media › Creators  » Authors » Don Casey  » PATH:  Contents  » Media › Creators  » Books » PATH:  Contents » T OPI C »

PAGE CONTENTS: ^ Overview. ^ Current members may view this book in our Library. ^ Editorial Reviews. ^ Product Details. ^ About the Author. Contact Information. Other Products, etc. ^ Related EAB  Main Topic Pages with Links. ^ Visit our FEATURED ARTICLES Home Page ! Thanks to our amazing contributors. ^ This Months Top 20 Most Popular Articles on our EAB  Website . ^ Members must SIGN IN to gain access to Members Only areas of this website . ^ Become an Academy Member and gain access to additional pages and programs ! ^ Comments for everyone to view: Submit to  Comments♣EverythingAboutBoats.org (Replace “♣” with “@”). ^ Academy Members’ Comments & Reviews that only current Academy Members can view. ^ Academy Members’ Exclusive Comment Submission Box. NOTES: Page is under development & may contain Drafts, Resources, etc. Please be patient. ♣

A fiberglass hull’s seamless nature leads many boatowners to conclude that repair must be difficult. Wrong. Here, clearly and abundantly illustrated, is all you need to know to seal joints, bed hardware, replace portlights, locate leaks, fix cracks and even holes, restore your hull’s gloss, renew nonskid decks, and much more. You’ll wonder what you were worried about.

From ΞSourceΞ.

THE ACADEMY eLIBRARY Academy Members may view the entire book.

FIRST CLICK HERE TO RETRIEVE YOUR CURRENT ACADEMY eLIBRARY PASSWORD. Copy (Ctrl + C) the password when it is revealed in its own window. THEN Return back to this page and CLICK HERE to open the book in its own viewer. Paste (Ctrl + V) the password when prompted in the viewer’s window.

IF YOU ARE NOT YET AN ACADEMY MEMBER, CLICK HERE to discover how you can become a Member and gain FULL access to thousands of expanded pages and dozens of excellent programs including our library !

CLICK HERE to view ALL the books , magazines and videos in our Academy eLibrary. Books are also listed by category on the Topic Pages found on the Right Sidebar  ⇒ CLICK HERE  to donate any books, magazines or videos to our Library.

Editorial Reviews

“The reader can almost feel the hand-holding this book provides-if [Casey’s other books] are only half as clear as this one, I would want to own them all.” — Dockside

Lots of details in a small package By A Customer on August 21, 2000 This is an excellent book for someone who knows nothing about fiberglass boat repair. It starts off with a brief discussion of the three major sealant types (polysulfide, polyurethane and silicone) and when to use each. Other sections cover the different types of resin, epoxy choices, etc. etc. Excellent information when trying to decide which of the gazillion products to purchase in the boating catalogs. Major sections include Leaks (finding and fixing, installing deck hardware), Restoring the Gloss (polishing and scratch repair), Deck Repairs (stress cracks, voids, nonskid surfaces, and teak decks), Laminate Repair (fiberglass layup, types of resins, epoxy), Core Problems (wet core, stiffening), Hull Repairs (gouges, blisters, impact damage), Keel and Rudder Damage (centerboard pivots, weeping keels, etc.) This little book is not afraid to tackle big projects–the Core Problems section for example shows the repair of a huge 2-foot diameter section of rotted core. The book makes it sound easy, but I’d rather not think about that much work. The section on gelcoat–what it is, how it is manufactured, and how to keep it looking good as long as possible–is by itself worth the price of the book.

2nd best book on Fiberglass repairs, and not just for sailboats By R. Young on March 7, 2006 While I actually like “Fiberglass Repair: Polyester or Epoxy” by David and Zora Aiken a touch better than this book, they are both strong. They both have lots of clear ILLUSTRATIONS, which to my mind are preferable to photos at depicting this sort of information. Blister repair (not addressed at all in older books on fiberglass repeair), wet deck cores, gelcoat cosmetics are all covered, as well as a good discussion of when to use Epoxy resins versus the cheaper Polyesters. I recommend this book for owners of ALL fiberglass boats, as the construction and repairs are quite universal. The relatively large format of this book helps the clarity of the drawings, and makes it possible to imagine using it like a cookbook, propped open on the workbench as you step through the steps.

Product Details

Publisher: International Marine/Ragged Mountain Press; 1 edition (January 22, 1996) Series: IM Sailboat Library Hardcover: 128 pages

ISBN-10: 9780070133693 ISBN-13: 978-0070133693 ASIN: 0070133697

Book’s Webpage at Amazon.com

Book’s Webpage at WorldCat.Org

About the Author

Author:  Don Casey  (Miami, FL) is one of the best-known writers on boat maintenance today and the author of seven books, including the bestselling This Old Boat and Sailboat Electrics Simplified.

CLICK HERE For more about the author, their Contact Information and other products.

EverythingAboutBoats.org Related Main Topic Pages with Links

Media : ^ Authors, Editors, Publishers, Producers, Directors, Actors, etc : ^  Books : ^  Magazines : ^  Videos : ^  Websites :

EVERYTHING ON THIS PAGE OK? If there is anything on this webpage that needs fixing, please let us know via email To: Editor♣EverythingAboutBoats.org (Replace "♣" with "@")

THIS ARTICLE IS STILL EVOLVING! The page may contain rough drafts that include raw source materials.

Visit our FEATURED ARTICLES Home Page to see examples of our website's comprehensive contents!

Thanks to our amazing contributors for the steady flow of articles, and to our dedicated all-volunteer staff who sort, polish and format them, everyday we get a little bit closer to our goal of Everything About Boats. If you would like to submit an article, See Submitting Articles .

—  TOP 20 MOST POPULAR ARTICLES  —

Detroit Diesel 8.2 Liter “Fuel Pincher” V8 Engine Cummins V-555 & VT-555 “Triple-Nickel” V8 Diesel Engine Lehman 120 (6D380) Diesel Engine (Ford 2704C & 2715E) Ford Industrial Power Products Diesel Engines How to Identify Ford Diesel Engines Ford 2715E Diesel Engine Lehman Mfg. Co. Perkins Engines Universal Atomic 4 Sears Boat Motors: Motorgo, Waterwitch, Elgin, etc. Chrysler & Force Outboards Eska Outboard Motors Allison Transmission ZF Friedrichshafen AG Marine Surveyors by Country American Marine Ltd (Grand Banks) Boat Inspection (Types of Marine Surveys) Boat Builders: (A∼Z) (w/Vessel Types, Locale & Years Active) USCG NVIC 07-95 Guidance on Inspection, Repair and Maintenance of Wooden Hulls American Boat and Yacht Counsel (ABYC)

Layout of the EverythingAboutBoats.org Website's Pages

— Types of Webpages — This website consists almost entirely of 3 types of webpages as follows:

• EXAMPLE : – WEBSITE CONTENTS w/Links to MAIN TOPIC & Subtopic Pages:
• EXAMPLE : 02 – BOAT BUILDING, OUTFITTING, REFITTING & REPAIR:
• EXAMPLE : 02.06 – Boat Equipment:
• EXAMPLE : 02.06.08 – Propulsion Machinery:
• EXAMPLE : 02.06.08.01 – Engines w/Directory of Vendors .
• EXAMPLE : 02.06.08.01 –  ^  Ford Industrial Power Products Diesel Engines.
• EXAMPLE : 02.06.08.01 –  ^   ^  Ford 2715E Diesel Engine.
• EXAMPLE : 02.06.08.01 –  ^   ^  Ford OpManual - 2710 Range Diesel Engines.
• EXAMPLE : 02.06.08.01 –  ^   ^  Ford Service Manual - 2700 & 2710 Range Diesel Engines.

Clickable Links that lead to other webpages appear in Blue Text and usually open in a new window. Links in the Right Sidebar and most directories open in the current window, not a new window. Note in the examples above that these pages form a natural hierarchy. The unnumbered "^" pages are listed alphabetically in most tables. Media Titles in tables are distinguished by their smaller font size. Media ( Books , Magazines , Videos , Articles ,+) are treated as Products. Vendors' Product Documentation ( pDoc ) are considered Media . Destinations & Media Creators are treated as Vendors. All Website Pages are optimized for viewing on full-width disktop computer monitors, but can be viewed on phones.

— Contents of Webpages — Website Pages typically contain the following Sections:

• EXAMPLE : PATH: HOME ,  WEBSITE INDEX , WEBSITE CONTENTS » ∨ ∧ BOAT BUILDING & REPAIR  »  Boat Equipment  »  Propulsion » Engines » ∨∨ ∧∧  Ford , Ebro , American Diesel , AmMarine , Barr , Beta , Bomac , Bowman , Couach , Lees , Lehman , Mermaid , Parsons , Renault ,  Sabre , Thornycroft , Wortham Blake  » ∧ DO-IT-YOURSELF  » DIY Boat Building & Repair » DIY Schools & Classes » ∧ MEDIA w/Creator Directory  » Documentation , Books ,  Magazines ,  Videos ,  Websites »
• ( The "»" right pointing Guillemet  symbol shows the chain through the page links. )
• ( The "," comma between page links in the chain indicates pages are not subordinate, but are instead at the same level. See engine brands in the example above. )
• ( The "∨", "∨∨", "∨∨∨",+ symbols indicate that the path line continues with whatever follows the "∧", "∧∧", "∧∧∧",+ symbols respectively. "∧" Precedes each MAIN TOPIC Page. )
• PAGE CONTENTS ( Table of Contents with links to each main section on the page ).
• ( Many Topic Pages contain Directories of Vendors with Links ).
• ( Most Directory Listings are Alphabetical and/or by Locale ).
• ( Manufacturers, Resellers, Refitters, Yards, Surveyors, Clubs, Schools, Authors ,+ ).
• ( Boating & Travel Destinations are treated as Vendors on their own Vendor Pages ).
• ( Media created by a vendor is often treated as a Product on its own Product Page ).
• ( Boating & Travel Events are often treated as Products on their own Product Pages ).
• RELATED RESOURCES (Topics, Vendors, Products, Media:   Books, Websites ,+ with Links ).
• The Anchors Aweigh Academy's EverythingAboutBoats.org Header.
• A link to our Featured Articles EAB Home Page.
• Top 20 Most Popular Articles. ( The section that appears right above ⇑ this section ) .
• Layout of the EverythingAboutBoats.org Website's Pages. ( This very section ⇐ ) .
• Topics of Webpages. ( The very next section below ⇓ ) .
• What we have accomplished so far.
• Members must Sign-In to gain full access to Expanded Pages & Programs.
• Sign-Up ( if not already a member ).
• Public Comments (about the website & about this page) .
• RIGHT SIDEBAR ( Website Contents menu with links to Main Topic & Subtopic pages ). ( On some smart phones, the Right Sidebar may appear at the bottom of the webpage )

— Topics of Webpages — Website Pages are categorized under the following 16 MAIN TOPICS:

The MAIN TOPICS follow a natural progression from conception of the vessel thru its building, marketing, survey, financing, insuring, transport, moorage, use and upkeep. The MAIN TOPICS (all Caps) below are followed by their Main Subtopics with Links.

00 – HOME: CONTENTS ,  ABOUT EAB : Contact EAB , Abbreviations & Symbols , FAQ , GLOSSARY , ADs ,+ . 01 –  ABOUT BOATS w/Museum Directory : Early History , Recent History , Modern Vessel Types ,+ . 02 –  BOAT BUILDING, OUTFITTING, REFITTING & REPAIR: Materials , Equipment , Builders ,+ . 03 –  BOAT MARKETING: Boat Shows , Dealers & Brokers , Importing & Exporting , Auctions & Sales ,+ . 04 –  BOAT INSPECTION: Types of Marine Surveys , Marine Surveyors , Schools , DIY Inspections ,+ . 05 –  BOAT TITLES & VESSEL REGISTRY: Boat Title & Registration , Vessel Registry , Title Co's ,+ . 06 –  BOAT FINANCING: Conventional ( Banks , Credit Unions ,+), Unconventional (Creative) ,+ . 07 –  BOAT INSURANCE: Maritime & Recreational: Coverage, Carriers, Agents,+. , Claim Processing ,+ . 08 –  BOAT TRANSPORT: By Sea ( Piggyback , Delivery Skippers & Crews , & Towing ), Over-Land ,+ . 09 –  BOAT HAULING & LAUNCHING: Drydocks, Ways, Lifts, Cranes & Hoists , Launch Ramps ,+ . 10 –  BOAT MOORAGE & STORAGE: Builders , Anchorages , Marinas , Yards, Racks & Stacks ,+ . 11 –  BOATING ORGANIZATIONS: Yacht Clubs & Sailing Clubs , Paddling Clubs , Boat Owners ,+ . 12 –  BOATING & TRAVEL: Events , Destinations , Boat Rentals & Charters , Cruises , Voyages ,+ . 13 –  BOATING & MARITIME EDUCATION: Recreational Seamanship , Ship's Master & Crew ,+ . 14 – MARINE LAWS & REGULATIONS : International & National Laws ‚ Lawyers ‚  Investigators ‚+ . 15 –  DO-IT-YOURSELF: DIY Boat Building & Repair , DIY Boat Sales , DIY Boat Surveys , DIY Classes ,+ . 16 –  MEDIA  w/Creator Directory + Academy eLibrary : pDocs , Books , Magazines , Videos , Websites ,+ .

The above MAIN TOPICS and a more detailed listing of Subtopics can be found on the Website Contents page and on the Right Sidebar .

What we have accomplished so far . Anchors Aweigh Academy and its EverythingAboutBoats.org website.

• Published over 50,000 website pages about boats and boating, bringing us closer to reaching  our goal of becoming "The ultimate reference resource about boats and ships for everyone from the beginning recreational boater to the seasoned professional mariner!"
• Published over 300 website main topic webpages, many with full articles on the topic. See our Website Contents or the Right Sidebar for the listing of the main topic pages.
• Published over 9,000 marine vendor webpages, all with their contact information, most with a description of their products and services, many with product documentation, specifications and independent reviews. (incl.: Boat designers, boat building tools, material and equipment manufacturers and suppliers, boat builders and dealers, yacht brokers, marine surveyors, boat insurers, boat transporters, skippers and crews, boatyards and marinas, yacht clubs, boat rentals and yacht charters, boating, seamanship and maritime schools, marine law attorneys and expert witnesses, boat refitters and repairers, book authors, magazine publishers, video producers, and website creators)
• Acquired over 120,000 pages of product documentation including Catalogs, Brochures, SpecSheets, Pictures, Serial Number Guides, Installation Manuals, OpManuals, Parts Catalogs, Parts Bulletins, Shop Manuals, Wiring Diagrams, Service Bulletins, and Recalls. And have made all viewable to Academy Members through our EAB website eLibrary .
• Acquired over 1,200 books and magazine back issues in our academy library and so far have made over 700 viewable to Academy Members through our EAB website eLibrary .
• Published over 500 DIY How-To articles about boat design, construction, inspection, operation, maintenance, troubleshooting and repair. We are working hard to do more.

We are currently formatting and polishing the Anchors Aweigh Academy online and hands-on courses. Our Marine Surveying  course has proven to be excellent for both the beginner and the seasoned surveyor, and especially helpful to the Do-It-Yourselfer.

Current Academy Members must SIGN IN to gain FULL access to this website including expanded pages and valuable Academy programs like our Academy eLibrary and our Ask-An-Expert Program! If your membership has expired, CLICK HERE to Renew .

IF YOU ARE NOT YET AN ANCHORS AWEIGH ACADEMY MEMBER, CLICK HERE to discover how you can become a Member and gain FULL access to thousands of expanded pages and articles, and dozens of excellent programs WITH JUST A SMALL DONATION!

Comments for Public Viewing

Submit any comments for public viewing via email To: Comments♣EverthingAboutBoats.org ( Replace "♣" with "@" ) Please remember to put this webpage's title in the subject line of your email. All comments are moderated before they appear on this page. See Comment Rules .

General Comments About the Website

FROM Donald:  " This is an awesome website. I found the information that I needed right away from one of the over 20,000 free articles that you provide as a public service. I'm surprised that so much if this site is free. But I still signed up so I could access the thousands of expanded pages, interesting articles, and dozens of valuable programs! The member's library of books, magazines and videos that I can view online is really terrific! I understand that you and your staff are all unpaid volunteers. Please keep up the good work. And I commend you for your plans to add another 10,000 free informative articles over the next year. I'm thrilled to support you in this endeavor with my small membership donation. Thanks again for all your hard work. "

FROM Huey:  " I agree with my Uncle, I too have found the articles to be very enlightening. They say that it will take about 100,000 articles to cover the full scope that they have envisioned for the website. They have over 20,000 articles so far and that's doing pretty well, but it could take several years to get the rest. I also noticed that many of the Main Topic Pages and some of the article pages are still in the rough draft stage. I guess that they will fill in as they can get volunteers to work on them. But what I can't figure out is why anyone would spend the time writing informative in depth articles just to give away free to this website for publication? What's in it for them? "

FROM Dewey:  " Well Huey, to me It looks like most of the articles on this website are written by very informed people, like boating instructors, boat designers, boat builders, riggers, electricians, fitters, marine repair technicians and marine surveyors. Writing such articles helps establish them as knowledgeable professionals. After all, this website was originally created by a school for marine technicians and marine surveyors. The website is growing in content every day. They even had to move to a bigger, more powerful server because the website's traffic has been growing exponentially. "

FROM Louie:  " I agree with everyone above. This site is quickly becoming the ultimate reference resource about every aspect of boats and ships for everyone from the beginning recreational boater to the seasoned professional mariner. I use the topic pages on the right sidebar to browse around the website. It's like a Junior Woodchucks' Guidebook for Boaters. Their Members' Library of over 300 popular and obscure books and over 200 magazine back issues that can be viewed online is fabulous. The Academy's magazine is especially informative. On top of that, there is the "Ask-An-Expert program for members where you can get an expert's answer to any of your boat questions. And a whole years membership is only $25. What a deal! I really love being part of this "Everything About Boats" community and help provide thousands of helpful articles free to the public. I think that I'll sit down right now and write an article about my experiences boating with my uncle. "

FROM Scrooge: " You rave about this website like it was the best thing since sliced bread. Well, I think it stinks. Sure, it has a lot of good information for boaters, and they're adding more every day, but it will probably never be finished. Furthermore, I don't even own a boat. And I wouldn't have a boat even if someone gave me one. Boats are a waste of money and time and energy and money! They're just a hole in the water you pour money into. If you gave me a boat, I'd sell it quicker then you could say Baggywrinkle. Then I'd lock up the cash with all my other money so I could keep my eye on it and count it every day. Bah humbug. "

FROM Daisy:  " I'm just so glad that Donald got the boat so we and the boys could enjoy boating — together. And of course all of the girls, April, May, and June, love to be on the water too, especially when that is where the boys are. Oh poor Scrooge, boating is more fun then you could possibly imagine. "

FROM Scrooge: " After seeing how much fun you all have on the water together, I regret that I didn't have that much fun when I was young. I've had a change of heart, and I'm giving each of you a Lifetime Academy Membership . "

FROM Editor:  " For those of you that have stayed with us this far, many thanks, and we hope that you found this little narrative informative. Your faithful support inspires us to keep working on this phenomenal website. We know that we have a lot more to do. Ultimately, we hope that we can help you enjoy the wonder filled world of boating as much as we do. We are all waiting to see what you have to say about this webpage article. Submit any comments via email To: Comments♣EverythingAboutBoats.org (Replace "♣" with "@"). Be sure to include this page's title in the subject line. Also, your corrections, updates, additions and suggestions are welcomed. Please submit them via email To: Editor♣EverythingAboutBoats.org (Replace "♣" with "@"). It has been truly amazing to see what we have been able to accomplished when we've worked together. Thanks to all those that have donated their valuable time and energy, and a special THANK YOU to all that have supported this cause with their membership donations. "

Comments About This Particular Page

FROM ΞNameΞ: “ Be_the_next_to_comment_about_this_page. ” {230316}

• 2024 BOAT BUYERS GUIDE
• Email Newsletters
• Boat of the Year
• 2024 Freshwater Boat and Gear Buyers Guide
• 2024 Boat Buyers Guide
• 2024 Water Sports Boat Buyers Guide
• 2023 Pontoon Boat Buyers Guide
• Cruising Boats
• Pontoon Boats
• Fishing Boats
• Personal Watercraft
• Water Sports
• Boat Walkthroughs
• What To Look For
• Best Marine Electronics & Technology
• Watersports Favorites Spring 2022
• Boating Lab
• Boating Safety

Dryboat Treatment for Wet Hull Core

• By Kevin Falvey
• Updated: January 25, 2019

Tim put his meticulously maintained 10-year-old 36-foot sport-fisher up for sale last spring, and he soon found an eager buyer.

All that remained was for the boat to pass the survey, and the money — a down payment for his next boat — would be Tim’s to spend.

It failed. The surveyor discovered wet hull core with a moisture meter, and subsequently pulled hull fittings and portholes to physically reveal the wet balsa core. Tim returned the deposit to the buyer, who left angry. And he was stuck with $95,000 worth of unsaleable boat.

Learn About Different Hull Construction Types

Of course, he might have been able to sell the boat at a fire-sale price, but that would have meant walking away from many tens of thousands of dollars. Plus, “I wanted to sell the boat with a clean conscience,” Tim says. Traditional methods for dealing with wet core, including cutting, chiseling, replacing and reglassing, can also cost $40,000 to $50,000 or more. Not to mention the destructive damage such measures incur. Ugh!

How-To Drill Into and Install Accessories in Cored Hulls and Decks

Enter Dryboat. This Michigan-based moisture-remediation firm offers a mobile, nondestructive system to dry out cored fiberglass boats. According to company president Scott Richmond and developer Jon Bartnick, the process restores the affected areas to moisture levels acceptable by the builder. It is the only method they know that maintains the original design of the manufacturer, as well as the structural integrity of the affected vessel.

I saw it in action. In simple terms, the first step is to determine the extent of the moisture intrusion, using a moisture meter, and by mechanically removing fixtures and drilling exploratory holes. Next, a series of holes, sized to fit the application, is drilled. Into these are inserted hoses connected to the system, which is housed in a trailer and runs 24/7 until the boat is dry. All of this, plus the price, varies from job to job, depending on circumstances. For Tim’s boat, it took a month and “$1,000 worth of electricity, though the weather was very damp when we started, which lengthened the drying time,” Tim explains.

Read Next: Inspecting Your Boat’s Finish

Once the structure is dry, the holes need to be repaired and repainted or regelcoated. Tim, an auto-body man, did that work himself. And his business’s yard provided a space to run the equipment all the time without extra cost or complaints.

Tim’s Dryboat bill was $13,000. His boat passed the survey, and he sold it for $85,000. Subtracting the $15,000 he’d spent on remediation, that netted him $70,000. He was happy with that, given the expense of the alternatives, plus “I sold it with a clear conscience,” he says.

More Information Dryboat – 855-379-2628; dryboat.com

Five Tips For Preventing Wet Core In Your Boat’s Structure

The boater in this story was caught by surprise. He didn’t realize his boat’s hull core was soaking wet until a marine surveyor turned it up during a pre-purchase inspection arranged by a potential buyer. To help avoid a similar situation yourself, take these five proactive and precautionary measures.

Learn the proper way to install accessories in cored hulls and decks . Whether you are adding a transducer, an antenna; replacing a hatch; or repairing a bowrail stanchion, the procedure for cutting and drilling holes in cored laminate are more complex than the techniques that apply to solid fiberglass. Basically, the cutout must be sealed as well as sealing the fitting

Pull through-hull fittings, engine mounting bolts and other penetrations on a periodic basis in order to inspect the core and make sure water is not getting in.

Reseal fittings and fixtures regularly. We can’t give you a specific time frame for this, because different caulks and different environmental conditions, result in the need to re-seal or re-caulk at different rates. Bottom line, caulk isn’t forever, so pull and reseal fuel fittings, engine bolts, antenna mounts, rail stanchions…..any fitting that passes through or into the core or that is fastened through or into the core—needs to be resealed regularly.

Buy a moisture meter and use it if you have a cored hull. These can be had for as little as $250. Of course, if you don’t want to buy a meter and learn how to use it, you can always hire a marine surveyor to check your boat’s core material for moisture periodically.

Inspect your boats finish for irregularities and flaws that might indicate structural concerns.

• More: boat maintenance , How-To

More How To

I Learned About Boating From This: Capsize, Rescue and Lessons Learned

Should You Abandon Ship During a Boat Fire?

38 Top Make-Ready Tips for the Spring Boating Season

On Board With: Andrew Robbins

Using Hydrofoils to Improve Boat Performance

We Test Interlux Trilux 33 Aerosol Antifouling Paint

Boating Shoes for Spring and Summer

MasterCraft Celebrates International Women’s Day With Fourth Annual ‘Let Her Rip’ Campaign

• Digital Edition
• Customer Service
• Privacy Policy
• Cruising World
• Sailing World
• Salt Water Sportsman
• Sport Fishing
• Wakeboarding

Many products featured on this site were editorially chosen. Boating may receive financial compensation for products purchased through this site.

Copyright © 2024 Boating Firecrown . All rights reserved. Reproduction in whole or in part without permission is prohibited.

How to Repair a Damaged Balsa Core in Your Old Boat

There are different core materials used in the production of fiberglass boats. It is there to increase the thickness of the hull, while trying to keep the weight of the boat to a minimum. One of these core materials is end grain balsa. Yes, the same balsa you used to make model airplanes. But end grained balsa is a highly processed ultra light wood. It give stiffness to the hull. End grained balsa cored hulls have the ability to handle excessive loads.

But sometimes water does find its way between the layers of a fiberglass hull and the core starts to rot. It is a good idea to find the source of the rot, usually it can be traced to a screw that was run through the hull, or a hole that was cut through the hull that was not sealed properly. Water finds its way in and you have rot. I have seen boats almost forty years old with no rot, and boats less than 10 years old that are almost unusable due to excessive rot of the floor and the core. I’m sorry some boats are just doomed from the start. But if you find that old classic boat, don’t give up on it just because you find it has some balsa core rot. It can be fixed.

Here is how you fix bad balsa.

1. Figure out how big of an area needs repaired, and draw a mark a few inches beyond it.

2. Use some sort of cutting wheel that you can set how deep you are cutting. I have used a circular saw for this, until I found better tools it works great. Set your depth at about 1/4inch or less, and cut around the area you have marked.

3. Use something to pry under the edge of the glass. The only thing holding the glass down would be the good balsa that is still there. The rotten balsa should give way quite nicely.

4. Set the piece you cut out aside to use as a pattern for new glass. Make your new pieces. Make at least one piece the same size, and the rest a few inches bigger. Use either heavy roving or biaxial cloth.

5. Use a wide wood chisel and a hammer to chip away all the balsa that is exposed. Try to get as much out as you can before you break out the grinders. Its rotten, it should come out easy. Go to someplace like www.fibreglast.com and order some new balsa. If you cant find any locally.

6. Use a sander or a grinder to clean up the inner skin.

7. Cut 2 pieces of 1-1/2 ounce fiberglass mat. The same size as your repair area.

8. Have your glass and balsa precut, then use your brush and wet out the repair area with resin. Then lay one of the pieces of 1-1/2 ounce mat on some cardboard and wet it down with resin, then take it and place it down in your repair area, and brush out all LARGE air bubbles. Don’t worry about any small ones, as they don’t matter for what you are doing.

9. Take your precut balsa and brush resin on the side that does not have the fabric holding it together, then quickly place it in the repair area over the still wet glass mat that you just placed in there. Use your hands to press it in as best as you can. After you get it in place. Take some wax paper and cover the entire repair, then cover that with cardboard. Place any kind of weight you can find on top of the card board. Books, magazines, newspapers, anything.

10. Now walk away for at least 2 hours. Have lunch, drink a wobbly pop, what ever you want, just leave it alone for at least 2 hours.

11. Now remove the weights, the cardboard, and the wax paper should have kept the cardboard from sticking, you are ready to continue.

12. Use a filler like dura-glass to fill in around the repair area, there will be some gaps between the old area and the new area. Fill these areas flush with the level of the new balsa, don’t fill them to the level of the old glass layer. Let this set up. Then sand smooth if needed.

13. Brush a layer of resin onto the new balsa over lapping onto the old glass. Wet the other piece of 1-1/2 ounce mat on the cardboard again, then place the mat onto the repaired area. Brush out the LARGE air bubbles ONLY right now. Take the piece of biaxial glass or roving, that is the same size as the repair and wet it out on the cardboard. Then place it on top of the still very wet mat. Use a plastic or rubber squeegee to work all the air bubbles to the sides and out. Do this as good as you can.

14. Take the last piece of biaxial or roving and wet it out on the cardboard, the place it over the still wet glass you just laid down. Use a squeegee to work all the air bubbles to the sides and out. Keep working at it until all the air is gone or the resin starts to set up.

15. Drink another wobbly pop, cause you just fixed your boat.

Others are Reading

• Print Article

People Who Read This Also Read:

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Prove You\'re Human * 8 × nine =

• CREATE AN ACCOUNT
• Boat Cover Finder
• Bimini Top Finder
• Boat Propeller Finder
• Engine Parts Finder
• Anchor & Dock
• Watersports
• Clothing and Footwear
• Engine Parts
• Cabin and Galley
• Covers and Biminis
• Electronics
• Paint and Maintenance
• Pumps and Plumbing
• Anchor Chains & Ropes
• Boat Fenders
• Boat Mooring
• Boat Protection
• Dock Storage & Protection
• Ladders, Steps, & Platforms
• Top Sellers

• Fishing Rods
• Fishing Reels
• Fishing Rod & Reel Combos
• Fishing Tools & Tackle Boxes
• Fishing Line
• Fly Fishing
• Fishing Bait & Fishing Lures
• Fishing Rod Holders & Storage Racks
• Fish Finders, Sounders & Sonar
• Trolling Motors
• Fishing Nets
• Fishing Downriggers & Acessories
• Fishing Outriggers & Acessories
• Fishing Kayaks
• Fish Cleaning Tables

• Inflatable Rafts
• Paddle Boarding
• Paddles & Oars
• Wakeboard, Wakesurf & Ski
• Wakeboard Towers
• Tow Ropes & Handles
• Life Jackets & PFDs
• Snow Sports
• Roof Racks, Carriers, Dollies

Men's Clothing

• Accessories

Men's Footwear

• Atheltic Shoes
• Water Shoes

Women's Clothing

• Dresses & Skirts

Women's Footwear

• Fuel Systems
• Sacrificial Anodes & Zincs
• Generator Parts
• Inflatable Boats
• Propeller Parts & Accessories
• Boat Manuals
• PWC Parts & Accessories

• Fishing Boat Seats
• Offshore Boat Seats
• Ski Boat Seats
• Pontoon Boat Seats & Furniture
• Boat Seat Pedestals & Hardware
• Boat Seats by Manufacturer
• Boat Tables & Hardware
• Boat Seat Covers
• Boat Seat Vinyl
• Floating Boat Cushions

• Barbeque Grills
• Boat Drink Holders
• Cabin Accessories & Hardware
• Boat Ventilation
• Interior & Cabin Lighting
• Marine Teak Products
• Carbon Monoxide & Smoke Detectors
• Binoculars & Telescopes

Boat Bimini Tops

• Bimini Top Accessories
• Pontoon Bimini Tops
• Other Biminis
• RV & Trailer Covers
• Boat Shrink Wrap & Accessories
• Boat Shelters

Boat Covers

• Boat Cover Accessories
• Boat Lift Canopy Covers
• Other Covers
• Boat Wiring & Cable
• Marine Batteries & Accessories
• Marine DC Power Plugs & Sockets
• Marine Electrical Meters
• Boat Lights
• Marine Electrical Panels & Circuit Breakers
• Power Packs & Jump Starters
• Marine Solar Power Accessories
• Marine Electrical Terminals
• Marine Fuse Blocks & Terminal Blocks
• Marine Switches
• Shore Power & AC Distribution

• Marine Audio & Video
• GPS Chartplotters & Accessories
• Electronic Navigation Charts & Software
• Digital Instruments
• Display Mounts
• VHF Radios & Communication
• Marine Radar
• Auto Pilot Systems
• Action Cameras

• Fiberglass & Epoxy Boat Repair
• Boat Paint & Varnish
• Marine Adhesives, Sealant, & Caulking
• Marine Engine Maintenance
• Boat Cleaners & Waxes
• Boat Cleaning Supplies

• Fresh Water Boat Systems
• Bilge Pumps
• Marine Plumbing Parts
• Wash Down Pumps
• Livewell Aerator Pumps & Live Bait Wells
• Toilet & Waste Pumps
• Marine Pump Replacement Parts

• Tires, Rims, & Hub Kits
• Boat Trailer Winches
• Boat Motor Supports & Transom Savers
• Boat Trailer Guides & Rollers
• Boat Trailer Fenders
• Boat Trailer Lights
• Boat Trailer Hardware
• Boat Trailer Jacks
• Boat Trailer Brakes & Axles
• Boat Trailer Tie Downs
• Couplers, Mounts, Hitches, & Locks

• Boat Deck Harware
• Marine Nuts, Bolts, & Screws
• Boat Handles, Pulls, & Rings
• Prop Nut Kits & Hardware
• Boat Cabin Hardware
• Marine Fasteners
• Boat Windshield Parts
• Boat Tubing & Rails
• Boat Mirrors
• Marine Tools & Tool Kits
• Boat Lettering

• Women's Clothing Deals
• Men's Clothing Deals
• Fishing Deals
• Anchor & Dock Deals
• Electrical Deals
• Electronics Deals
• Paint & Maintenance Deals
• Pumps & Plumbing Deals
• Boat Seats Deals
• Trailering Deals
• Camping & RV Deals
• Dealer Login

• Forums Login

• Search forums
• Boat Repair and Restoration
• Boat Restoration, Building, and Hull Repair

Injection repair of wet balsa core

• Thread starter Simplesailor
• Start date Jan 25, 2014

Simplesailor

• Jan 25, 2014

If this is a dupe, I apologize but my earlier post doesn't seem to have made it! I have discovered that water is entering the core of the coach roof on my 30 ft Nonsuch sailboat through failed bedding on the roof hatch. I plan to replace the hatch. So far there is no noticeable damage to the fiberglass around the hatch but a moisture meter shows that the core immediately around the hatch is wet. I have been told that wet core can be stabilized and the area strengthened by injecting Caviseal or some other substance into the area between the fiberglass layers. I am interested in any personal experiences with this type of repair. What did you use and how did you apply it, any lessons learned, etc.? Thanks  

• Jan 26, 2014

Simplesailor said: If this is a dupe, I apologize but my earlier post doesn't seem to have made it! I have discovered that water is entering the core of the coach roof on my 30 ft Nonsuch sailboat through failed bedding on the roof hatch. I plan to replace the hatch. So far there is no noticeable damage to the fiberglass around the hatch but a moisture meter shows that the core immediately around the hatch is wet. I have been told that wet core can be stabilized and the area strengthened by injecting Caviseal or some other substance into the area between the fiberglass layers. I am interested in any personal experiences with this type of repair. What did you use and how did you apply it, any lessons learned, etc.? Thanks Click to expand...

Seaman Apprentice

• Jan 27, 2014

Re: Injection repair of wet balsa core I've injected thickend resin in dried out soft plywood as a last option before. The boat had been drying for a couple of months before I drilled holes and injected polyester thickend with microglass balloons. The area got much stiffer, but some hard spots can be felt if you know what too look for. I've also helped a friend do the same on his 33' sailboat where the balsa was rotted out under a winch. If I would do it again I would use epoxi instead but same procedure.  

Woodonglass

Supreme mariner.

• If the core is not rotted, it can be dried out. To determine if the core is rotted, get at the back side of the laminate and drill a grid of 1/8” holes in a 1” checkerboard arrangement. Of course you are not drilling through both sides of the laminate. Drill only through the inside. Do this over the entire area that has a moist core. To get a neat, consistent pattern of holes I apply sticky back cabinet shelf paper. It comes in a checker board design.
• Clean out the flutes of the drill every few holes. Unrotted balsa will have no smell or smell like resin and it will be fibrous when you roll it in your fingers. Rotted balsa will smell moldy and have more of a mushy or dusty feel. If you are really unsure, drill a ?" hole and pick some of the balsa fibers out with a tweezers. Rotted fibers will crumble or mush. Good balsa will be much harder to remove and it will be very fibrous.
• If you are lucky enough to live in a northern climate, where the temperature moves above and below freezing in the spring and the fall, nature will dry the laminate after you’ve drilled the hole grid described above. Here, ice crystals form as the temperature drops and the moisture is driven out of the wood. Ever look at a loaf of freezer burnt bread with ice crystals collected in the plastic bag? This occurs when the temperature inside the freezer fluctuates above and below freezing. What you want is a freezer burnt core in your boat.
• If you are not in a northern climate, or worse you are in a high humidity climate, I cannot help you. Text books talk about injecting alcohol, using tents and halogen lights but I have not used these methods.
• If the core is rotted, you need to fix it or the lack of core support will lead to much bigger problems. The question is when can you use simple injection versus tearing out the rotted area and replacing it?
• If the upper and lower fiberglass layers are structurally sound, the core can be repaired with injection. If the fiberglass does not show stress cracks or obvious hydrolysis (blisters or milky looking fiberglass), it will be fine.
• Large areas with stress cracks may be repaired with injection but I have not done that so I cannot predict the success. However, I can tell you this. I did do what was to be a temporary repair to a 30 foot Pearson Flyer that had a 6 inch crack in the hull. The outer hull had been punctured from a bad cradle pad. That was 10 years ago. When we injected the polyurethane from inside the hull, the polyurethane oozed out of the hull crack on the outside and then set up. The intent was to do a permanent repair after the racing season ended. A final repair was never done because the area around the temporary repair is stronger than the surrounding original hull.
• If she is a racing boat without a headliner the air holes can be left unsealed. But if a headliner is installed you must seal the air holes. Here’s why. The wet core was a potential problem because of possible delamination from rot or ice. But now that the core is open to air another problem can occur, mildew. Mildew requires air and moisture. If a headliner is installed and a deck leak traps moisture between the headliner and deck, mildew is sure to occur. Mildew is a sure way to delaminate any structure but you can avoid it if you cut off the air by filling the air holes. While you are doing that you may as well fill any voids in the core at the same time."

cruisers5357

• Feb 11, 2014

Woodonglass said: My research found this which might be of interest... " When can a core simply be dried out instead of injected? If the core is not rotted, it can be dried out. To determine if the core is rotted, get at the back side of the laminate and drill a grid of 1/8? holes in a 1? checkerboard arrangement. Of course you are not drilling through both sides of the laminate. Drill only through the inside. Do this over the entire area that has a moist core. To get a neat, consistent pattern of holes I apply sticky back cabinet shelf paper. It comes in a checker board design. Clean out the flutes of the drill every few holes. Unrotted balsa will have no smell or smell like resin and it will be fibrous when you roll it in your fingers. Rotted balsa will smell moldy and have more of a mushy or dusty feel. If you are really unsure, drill a ?" hole and pick some of the balsa fibers out with a tweezers. Rotted fibers will crumble or mush. Good balsa will be much harder to remove and it will be very fibrous. How can a core be dried? If you are lucky enough to live in a northern climate, where the temperature moves above and below freezing in the spring and the fall, nature will dry the laminate after you?ve drilled the hole grid described above. Here, ice crystals form as the temperature drops and the moisture is driven out of the wood. Ever look at a loaf of freezer burnt bread with ice crystals collected in the plastic bag? This occurs when the temperature inside the freezer fluctuates above and below freezing. What you want is a freezer burnt core in your boat. If you are not in a northern climate, or worse you are in a high humidity climate, I cannot help you. Text books talk about injecting alcohol, using tents and halogen lights but I have not used these methods. When can a core be fixed with polyurethane injection versus traditional reconstruction? If the core is rotted, you need to fix it or the lack of core support will lead to much bigger problems. The question is when can you use simple injection versus tearing out the rotted area and replacing it? If the upper and lower fiberglass layers are structurally sound, the core can be repaired with injection. If the fiberglass does not show stress cracks or obvious hydrolysis (blisters or milky looking fiberglass), it will be fine. Large areas with stress cracks may be repaired with injection but I have not done that so I cannot predict the success. However, I can tell you this. I did do what was to be a temporary repair to a 30 foot Pearson Flyer that had a 6 inch crack in the hull. The outer hull had been punctured from a bad cradle pad. That was 10 years ago. When we injected the polyurethane from inside the hull, the polyurethane oozed out of the hull crack on the outside and then set up. The intent was to do a permanent repair after the racing season ended. A final repair was never done because the area around the temporary repair is stronger than the surrounding original hull. High pressure polyurethane injection Some jobs need high pressure injection and a very thin polyurethane sealant. Basically these are places where you cannot remove the core. Here, a grid of 1/8? holes needs to be drilled in the back side of the laminate. Or, you may be filling the hollow space within a rudder. The good news is that Vulkem 45, a thin polyurethane sealant, is available from Home Depot at a fraction of the cost of tradition thick, marine polyurethane such as 5200. Vulkem 45 comes in quart cartridges and it is thin enough to go through a pin hole. You can fill a handheld grease gun directly from the cartridge of Vulkem 45. Vulkem 45 is good for injection made under foot such as injection into a hull from the inside. Vulkem 45 can also work for large vertical injection such as a rudder. But for over head jobs use Vulkem 640. It is sold in gallon pails at a professional construction material dealer. Call Vulkem for a dealer location. Where as 45 is self leveling, 640 is the opposite. It will hang overhead yet it is quite thin. Buy a cheap grease gun from an automotive store. For the grease gun buy a POINT fitting at an automotive parts store such as NAPA and replace the normal grease fitting. Pump caulk into each of the 1/8? holes in your grid until caulk is oozing out of the hole(s) ahead. You may need to plug the hole(s) you?ve already done with golf tees. Buy a few bags of tees. Use a grease gun filled with Vulkem 640 or 45 and inject it into the core. Each 1/8" hole will take about 1.5 pumps from a handheld grease gun before you meet resistance. If you do not meet resistance, just keep pumping until sealant is coming out of at least one adjacent hole. You will hit some voids in a core that take a couple dozen pumps. These are spots where there was no core originally. This is typical on corners. Or the core may be rotted and you are compressing the rotted core material with the sealant. Once the sandwich has been dried and injected, water cannot reenter because the sandwich is solid. As a bonus, once the sandwich cures, it will feel much more solid. Note, it may take several months to fully cure. Low pressure polyurethane injection If you have removed the core, there is no need for high pressure or a thin polyurethane sealant. For example, if you have removed a 1 ft diameter circle of core material around a through fitting, the void will be easy to fill. Use 5200 or Vulkem 921 above the water line. Note, 921 is only available at a commercial construction material distributor. Removing a core around a through fitting is tedious but can be done. You will be able to remove the core for about 6? around a through fitting. To do this, you can make a routing tool from a flexible screwdriver extension attachment made by Vermont. Use a cutting wheel on a Dremmel to cut teeth in the end of the Vermont screwdriver attachment that normally holds the screwdriver bit. Then put the flexible screwdriver attachment into an electric drill and route out the core sliver by sliver. For a through hole fitting, after the core is removed, drill three holes at the edge of the removed core in a triangular pattern. Then wrap the through hull/deck fitting in enough cellophane so that it is hard to press it into the hole. Force it into the hole and inject caulk into the first of the three holes until it oozes out of the next hole, plug the hole and move on until all three holes are under pressure. Note, it takes weeks to months for the polyurethane to fully cure. Polyurethane cures in the presence of moisture so it will eventually cure. A partial cure is good enough to screw things back together. Wait a few weeks before doing that. After the core is dried can the air holes drilled under the deck be left open? If she is a racing boat without a headliner the air holes can be left unsealed. But if a headliner is installed you must seal the air holes. Here?s why. The wet core was a potential problem because of possible delamination from rot or ice. But now that the core is open to air another problem can occur, mildew. Mildew requires air and moisture. If a headliner is installed and a deck leak traps moisture between the headliner and deck, mildew is sure to occur. Mildew is a sure way to delaminate any structure but you can avoid it if you cut off the air by filling the air holes. While you are doing that you may as well fill any voids in the core at the same time." Click to expand...

Re: Injection repair of wet balsa core There is a company with a (portable) patent-pending process that injects extremely dry (<2% RH) heated air into 1/4" to 1/2" holes to dry out wet balsa and wet stringers. You can google the company it is called Dryboat  

Moskva-Class Cruisers

Separate design teams often attempt to meet a set of ship specifications with completely different, although equally valid, strategies. To fulfill the requirements issued in April 2169 for the successor (NX-223) to the Daedalus class, which was introduced at the end of the Romulan War, Prosser & Ankopitch proposed a ship with an extremely large, spherical command hull attached to a nearly vestigial engineering hull. The proposal from the Mikoyan-Tupolev-Dassault Bureau used a long narrow command hull with a minimal frontal silhouette counterbalanced by an equally long engineering hull.

The engineers at Tezuka-Republic decided that the division of ship's functions between a command/crew hull and an engineering hull was arbitrary and unnecessarily restricted design options. Therefore, rather than gathering all the specified facilities in a single hull, their design TR-223A spread them across two hulls, as in Daedalus , and segregated the SSWR-IV-C warp core to a "bustle" at the extreme aft end of the secondary hull. This bustle could be separated easily and quickly from the rest of the engineering hull in the event of a warp core breach. The now-unpowered warp nacelles would then be shed. In this way, the demands of safety would be met without warp dynamics being degraded either by an excessively large frontal silhouette or by longitudinal warp field imbalance.

Although the Ship Specifications Review Board praised Tezuka-Republic for its creative solution to the problem of admittedly contradictory requirements for extreme safety and improved warp performance, they were forced to disqualify design TR-223A for not precisely meeting contract specifications. Therefore, in October 2171, construction contract NX-223 for Starfleet's new cruiser was awarded to Prosser & Ankopitch for what would become the Wasp class .

However, almost no one was happy with the new Wasp ships. Even before the contract was awarded, voices within Starfleet and within industry had strongly criticized the specifications of April 2169. These critics charged that they would lead to a mediocre, albeit safe, fighting ship. Two separate classes were needed, not a single class that was neither a proper explorer nor a proper warship. When Wasp was finally launched in 2173, her performance during precommisioning trials clearly showed that the critics had been correct. Although the performance problems were related in part to the continuing unavailability of the more powerful Tezuka-Republic Hiryu ("Flying Dragon") mark III warp nacelles, Wasp was obviously not the ship Starfleet had hoped for.

In a second attempt to obtain a reliable and capable warship, new specifications (NX-374) were issued in September 2175, little more than a year after USS  Wasp had entered service. Adding to this sense of urgency were intelligence reports suggesting that the Romulans had either developed or otherwise acquired matter/antimatter (M/AM) reactors. This time the specifications put less emphasis upon safety. The original requirement for completely separate command and engineering hulls was eliminated; instead, any hull configuration was allowed as long as the warp core could be quickly separated from the rest of the ship. Furthermore, requirements for speed, acceleration, and maneuverability both under impulse power and under warp power were increased, as were performance levels for target acquisition, tracking, and servicing.

These new specifications were a clear, albeit belated, admission that the critics had been correct all along: one class could not be expected to serve as both an explorer and a main battleship. In fact, starship technology was not considered sufficiently mature for a single ship to adequately fulfill both mission profiles until 2245, when the Constitution -class heavy cruiser was launched. (The controversy continues even today in the wake of the problems of the Galaxy -class explorer.)

Luckily, the designers and engineers at Tezuka-Republic had not been idle since their disappointing loss of the Wasp contract in 2171. Instead, they had spent their time refining design TR-223A so that their new entry (TR-374A) was markedly superior to what had been submitted 5 years earlier. In particular, the new SSWR-V warp reactor allowed the bustle to be made smaller, lighter, and even more easily separable. Therefore, it was hardly surprising when in November 2176 Tezuka-Republic was awarded the production contract over designs from Shimata-Dominquez, Prosser & Ankopitch, Mikoyan-Tupolev Dassault, Monarch R&U, and Thornycroft/Ebisu for what was to become the Moskva class.

However, engineering prowess may not have been the only factor in Tezuka-Republic's winning of the contract. There were accusations that the delay in delivery of the Hiryu warp engines was an attempt by Tezuka-Republic to prevent Wasp from reaching her designed performance levels. While no conclusive incriminating evidence has come to light, the delivery of the long-awaited engines shortly before the scheduled launch of Moskva in December 2177 is certainly suspicious. Tezuka-Republic maintains that if their submission of 2169 had been selected, its performance would also have not have met design specifications without the Hiryu engines. However, critics charge that TR-223A was not as reliant as Wasp on the type of engine used. Furthermore, once the Wasp contract was awarded, and even after Wasp was launched, Tezuka-Republic certainly made no efforts to accelerate delivery of Hiryu.

These controversies were soon rendered moot as the new Moskva class was recognized as a significant advance in starship design. The most important new feature was Moskva's discoid primary hull. Earlier designs had chosen a spherical primary hull for reasons of economy. Simple geometric relationships dictate that a spherical hull has the smallest surface area for a given volume. Therefore, construction costs are lower and shields are more efficient. Furthermore, institutional inertia had led nearly all exploratory cruisers originating until that time from the National Aeronautics and Space Administration, the United States Astronautics Agency, the United Earth Space Probe Agency, and its successor organizations to have spherical hulls.

The designers of USS  Moskva employed a biconvex disc for several reasons. Their initial motive was to increase hull volume while minimizing both frontal and lateral silhouettes. A warship with large frontal and lateral silhouettes would be at a greater disadvantage in most tactical situations than would be a ship with an increased superior silhouette. However, the discoid hull allowed the traditional radial layout of command hulls to be retained.

More important than these tactical advantages were functional advantages. As was shown with the Wasp class, warp field geometry would have been awkward if a spherical hull with its relatively large frontal area had been used. The discoid hull was also found to channel warp field flow across its upper surface towards the bussard ram scoops of the warp nacelles. This channeling effect improved field efficiency at all power levels and speeds. As the understanding of warp field mechanics was refined, the trend towards saucer-shaped primary hulls would be intensified in later Starfleet vessels.

In most respects, the Moskva class continued design and engineering trends established in the Comet and Daedalus classes introduced at the end of the Romulan War. As in these classes, ship functions were clearly divided between a command/crew hull and an engineering/propulsion hull. The bridge was returned to its customary position atop the command hull and the shuttlecraft bay was again placed in the secondary hull. The fusion reactor was centered along the longitudinal axis of the ship, and impulse thrust ports exited immediately in front of the warp bustle detachment seam.

Weaponry was the then-standard mix of fusion-warhead missiles and lasers. New to this class was an early type of ultraphased pulse laser cannon, two of which were mounted in the chin of the primary hull. Although the on-target energy output of this new weapon approached that of early phasers, its power requirement was higher and its range was substantially less. However, subsequent refinements lead to steady improvement and, ultimately, to the development of true phasers in 2202. Although Moskva -class ships were the first to be fitted with phasers in 2204, lasers were still carried by the Moskva class and later classes until the 2220s. Finally, warp capability was supplied by the long-awaited Hiryu mark III drive units.

The first ship of the new class, USS  Moskva (NCC-374), entered service with Starfleet in April 2179. An additional 30 ships (NCC-375 to NCC-404) joined the fleet through 2183. Moskva -class ships gained immediate popularity with officers and crews. First, total laser firepower was increased some 75% over that in the preceding Wasp class. Second, because the ship's mass was more equally distributed along the longitudinal axis than in the Wasp class, Moskva was significantly more maneuverable at both sublight and warp speeds. Finally, the more warp-dynamic design allowed greater cruising and maximum speeds.

The Moskva class had an outstanding safety record. No ships were lost because of mechanical failures. However, an incident occurred aboard USS  Johannesburg in 2186 when a faulty nacelle flow monitor falsely indicated a runaway positive feedback power loop within the plasma flow governor. Believing that a catastrophic warp core explosion was imminent, Chief Engineer Roberta Bocharnikov ordered the warp nacelles and warp bustle to be separated. Although unnecessary, these maneuvers were successful in causing the separated warp core to initiate its automatic shut-down routine. The warp core, nacelles, and the rest of the ship were towed to Starbase 13, where they were successfully re-mated. Despite her supreme embarrassment, Bocharnikov oversaw the reassembly and relaunching of Johannesburg and retained her position as chief engineer.

Although most ships of the Moskva class had left front-line service by 2215, some continued to serve as auxiliaries and training vessels until the 2240s. After retirement from active duty, Moskva -class ships were used as testbeds for many emerging technologies owing to the similarities of their layouts to those of succeeding classes. USS  Moskva was the site of the first successful ship-to-surface transport of a Human being in 2206, and USS  Gato was the first ship to fire photon torpedoes in 2214. In addition, Taurus -class tugs, which entered service in 2182, and Sanford -class repair tenders, which entered service in 2185, were derived from the Moskva class and used the same primary hull and warp drive assembly.

The Moskva -class cruiser USS  Aurora (NCC-377), a participant of the Battle of Eohippus IV, is on display at the Starfleet Museum.

Standard displacement: 67,750 t

Crew complement: 160 (27 officers + 133 crew) Weapons: 8 Type VI laser turrets (8 × 1 mounts), 2 Type VII laser cannons (fixed mounts), 2 missile launchers with 36 Spartak missiles Embarked craft: 4 medium cargo/personnel shuttlecraft, 2 light personnel shuttlecraft, 5 fighter/scouts Warp drive: SSWR-V-A spherical cavity M/AM reactor with 2 Hiryu III nacelles Velocity: wf 4.0, cruise; wf 5.0, supercruise; wf 5.2, maximum Units commissioned: 31

Thomas Mobile Automotive Services

Contact and address, opening hours:, location & routing.

Family friendly, and family driven. These people helped me out in situations that not even the dealership would go through the trouble with. Because not only did they help with the cost of the repairs they made it so my opinions were know on what still worked and didn't make me buy stuff that wasn't needed. They even made the work look better then what the dealership could make it. I HIGHLY RECOMMEND coming here and do your business with these incredible people. I swear you will not regret it.

Picked up my car on time and even helped fix a dent I had from hitting a bear at no additional cost.

Great place, friendly people and fair prices best of all they will come to you and pick up your vehicle and deliver it back. Check it out you won't be disappointed

Called with unexpected problem came picked up vehicle fixed it and brought it back very nice people really appreciate you both and will recommend to anyone thanks again

GREAT CUSTOMER SERVICE ! I WILL BE BACK AND I WILL LET EVERYONE KNOW YOU GUYS ARE GOOD! GOOD LUCK TOMMY AND COURTNEY!!

Photos of Thomas Mobile Automotive Services

Thomas Mobile Automotive Services On the Web

Automotive shop | thomas' mobile automotive service | moscow, pa.

Thomas' Mobile Automotive Services is a business located on Main Street Moscow Pa. We bring to you a shop with a staff who have over 30 years experience. What sets us apart from the other shops in the area is that we are the shop that comes to you.

Thomas' Mobile Automotive Services - Home | Facebook

See more of Thomas' Mobile Automotive Services on Facebook. Log In. or. Create New Account. ... (570) 848-7287 . www.thomasmobileautomotive.com. Automotive Repair Shop.

Thomas' Mobile Automotive Services - About | Facebook

Thomas' Mobile Automotive Services. 132 likes · 12 talking about this · 1 was here. "The Shop That Comes To You" Services for most automotive needs....

Thomas' Mobile Automotive Services - m.facebook.com

Thomas' Mobile Automotive Services is on Facebook. ... Call (570) 848-7287 . 5.0. 5 of 5 stars. View 0 reviews. Related Pages. Stigma Studio professional tattooing.

PDF Lackawanna County Stations and Test Types Offered as of April ...

0802 lanes garage 251 s.r. 690 moscow 18444 (570) 842‐0938 o,v 9019 mar chet transit inc 200 watts rd moscow 18444 (570) 689‐2289 v aj63 thomas mobile automotive services inc254 n main st ofc right moscow 18444 (570) 848‐7287 v d389 a & b automotive inc 890 drinker turnpike moscow 18444 (570) 842‐9717 v

Similar businesses near me in Moscow, PA

• Spectrum Collision Center 211 Market St, Moscow, PA 18444, USA Car repair
• Randy's Garage RR 502, Moscow, PA 18444, USA Car repair
• Warren's Auto Services RR 7, Moscow, PA 18444, USA Car repair
• A J AUTO CENTER, INC. 1200 Drinker Turnpike, Covington Township, PA 18444, USA Car repair | Local government office | Car dealer | Store
• Dent Team llc 1406 PA-435, Moscow, PA 18444, USA Car repair
• Sebrings Auto Body Langan Rd, Covington Township, PA 18444, USA Car repair
• Torque Unlimited 1271 Becks Crossing Rd, Madison Township, PA 18444, USA Car repair | Store
• TRYGAR'S Auto Center and Kwik Lube 1180 Church St, Moscow, PA 18444, USA Car repair
• D & S Auto Repair & Supply 2021 Reservoir Rd, Madison Township, PA 18444, USA Car repair
• Sebrings Auto Body 144 Langan Rd, Covington Township, PA 18444, USA Car repair

Most Recent

• Renova Roofing & Construction [Roofing contractor]
• A-1 Roofing [Roofing contractor]
• Floors & Kitchens Today [Home goods store]
• Kingery Dental Health and Wellness [Dentist]
• Lifetime Windows & Doors [Roofing contractor]
• Simon's Plumbing [Plumber]
• Ryson Vacations Palm Springs [Lodging]
• Pleasant Hill Dental [Dentist]
• Center Square Family Dental [Dentist]

Today most viewed

• Akzo Nobel Aerospace Coatings
• Canger Engineering Associates
• Doddy's Liquor Mart
• CrystalCase
• Willow Pass Dental Care
• Norton Flooring
• Consolidated National Insurers
• Encompass Parts Distribution - TV Electronic & parts
• All About Breastfeeding
• Bates Electric
• Splash Studios - Video Editing and Post Production Amsterdam
• legit barbers
• Freeburn, Keith, PT, DPT
• MGMM Productions
• Grant Tire Services
• B & B Transmissions
• Trouble Free Auto
• Del Campo Joseph
• CompleteCare Vineland Health Campus
• Wreck & Mended Auto Body Shop
• Melinda R. Zellars, DPM

Home page   .   + Add listing   .   About   .   Privacy Policy   .   Terms of Service   .   Contact Us   .  

© 2024 BusinessYab.com All Rights reserved.