Restoring Cored Decks

Rob Squire, #96, Head-Over-Heels

Do not get discouraged! If it isn't broken, don't fix it. Repair what is trouble, worry about the rest later...if you need to.

Jackson, #184, BLACK DOG

Be sure to check out the Project Showcase for BLACK DOG's Core Makeover.

Jim Lydon, Swahili

(Test first)

Many of us East-Coast owners have faced this problem in the past. I believe as several others that safety is the most important factor. If you are contemplating some serious off-shore sailing you definately dont want to spend time in your berth wondering if I did this and that correct, and will it hold up? So the final decision willbe yours. In any event I can offer some food for thought, having seen the core material after removing the top deck sections of Swahilli.

1st water meanders everyware it can find its way to points under the deck you would-not believe. What looks like a simple softness to a stanchion area can move probably aft, quite a distance from the point you think the problem is.

2nd If the core is bulsa which I am assuming it is, it will act quickly to absorb the water distributing it along a line aft. In otherwords your mid-section of your deck may feel fine and probably is, however you may have a long section of saturation running along the stanchion lines. After my recoring job was complete several weeks later I opened the most aft cabinet on the starboard side and noticed a molasses like stain on the cabinets floor. Bad news! I found that water had meandered well past my stopping point of the recore project. Not onlywas this area saturated, but it was fast approaching the starboard pad-eye,a condition I located now during the refit.

3rd Consider the winters, this water has probably been freezing and thawing out many times. The effect on hardware support can be imagined. 4th These boats are old and Tritons are famous for water standing in spots for long periods, especially during times out of the water. Water can penetrate fiberglass: example hull blisters. The decks outer layer is quite a bit thinner than the hull. Water can saturate through.

So after some of my thoughts I put myself in your position and came up with a possible solution. Winter is here and I am assuming that any project will be started in the spring. Try this. Go below and drill several holes up into the core material down the entire length of the deck both starboard and portside along the stanchion line and then along the dog house line. Put some old plywood or cloths under the holes. Do the same on the forward deck. If you get immediate water you got a problem. Leave the holes open for the winter and occasionally check for dripping either in the form of water or that molasses like gunk. Dont make any decisions till after the spring thaw. Hope this has been of some help.

Jim Lydon, Swahili

(Repair procedure if necessary)

I have had several requests for information on the recoring of the deck on my Triton (Swahili) which I recored last year and I thought it may be of help to anyone contemplating this project. The method I utilized did not seem to cause any problems other than time consuming. A Friend of mine in the marine business for years now retired and sailing the Caribbean instructed me on this method.

First all deck hardware was removed. All sanding of the deck was to be done after the deck was removed on a table at waist height. This saves hours of work on your knees and in a bent over position.

Second-----Use a simple circular saw to cut through the deck. Be sure to use a carbide saw blade. Set the blade depth so that it just cuts through the decking depth or slightly into the balsa core. I did my deck in 3 different steps. Starboard side first Portside second and bow third. Each section was cut into 2 equal pieces. The starboard side was cut across at the level of the forward cabin and aft at the level of the dog-house. A second cut was made directly across from mid point between the large side ports. Repeat the process on the port side. The bow was divided into 2 sections forming 2 triangular shaped pieces with a cut directly down the middle.

Third The cutting process----With your circular saw cut along the rails of the starboard side. You will notice that there is a section on decking left about one and a half inches in from the rail. This is a result of the circular saws guide. THIS IS GOOD. This small piece of decking will give you some deck to glass the new pieces into place, avoiding having to glass right up too and over the rail. Take my advice this saves time. Cut along the dog-house in the same manner leaving the same one and a half inch of decking. Now cut across the forward section at the forward dog-house level and finally across at the aft section level with the companionway. The whole piece of decking should lift up very easily exposing the bulsa core that probably looks more like a sponge now. Put the piece of decking aside for now. This will be used as a template to cut your new core section later.

Scrape out all the old saturated core material using whatever it takes. Check under that inch and a half overhang if it is saturated you maywant to scrape it out. Mine was dry so I left it. If you scrape it out you will run into some extra work in cutting out some new core materialfor this overhang. After all the core material is out sand down the sub-decking with palm sander with 60 grit paper. Now look around for holes and seal them up with fiberglass tape and resin.

Repeat this process on the port-side. On the bow section remove the entire bow section in 2 pieces do not attempt to cut directly up to the bow point cut back several inches to avoid removal of the bows hardware. Cut directly from bow to the middle of the forward cabin. Remove the bow pieces and repeat the cleaning and scrapping process.

Now go to the work table and cut the starboard and port sections in two if you have not done so. Now do all your sanding here at waist level sand off the entire tops with a belt-sander with 60 grit. You can lightly sand the undersides if necessary. Now use your pieces as a template and cut your marine ply or whatever you decide on. Now you are ready to re-assemble.

The cut pieces should fit directly onto the sub decking in the shape of the cut out pieces. Glass the pieces onto the sub decking and let them dry out. Then fill any gaps with thickend resin. Glass over the ply lightly on the upper surface and let dry. Finally re-fit the cut out pieces of decking and glass them to the core material. Fill in the gaps with thickend resin and finally sand down and apply fiberglass tape over all seams. This is where that inch and a half of overhang comes in real handy you now have an attachment piece to tape to avoiding having to glass right up to and over the rails.

On the finishing aspects, I used a 2 part primer 2coats rolled on over the entire deck. Make sure your primer is compatable with your choice of finished paint. After the 2 coats of primer have been applied lay out your non skid pattern and tape off. I used a product from West Marine called Monster Grip. I rolled on a coat of 2 part primer and with a salt-shaker shook into the wet paint the Monster Grip repeating the process a second time. Then I covered the non skid areas with my choice of color Seattle Grey. Then I matched the boats color with Awl Grip Matterhorn white rolled and feathered around the non skid areas.

Note on the Bow sections I had to drill several screws up into the bow ply from below to hold them tight against the sub-decking while the glass was drying. I believe this is a result of the slight up-curvature of the bow.

This project is not difficult but very-very time consuming. Dont be intimidated about starting this project, once you get over the fear of cutting a hole in your deck your into it. And believe me the hole in your wallet if you had this done professionally would be a lot larger. Watch the weather and dont rush the project. Good luck.

A. J. Matthews, #605, Ay Mon

I guess it all comes down to how much time, energy, money and "spongy" you have. Take that and divide it by the safety factor that you wish to have during your crossing.

If water got to the core, first decide how or where it got there. There are two main causes for water getting under your deck. One is an improperly prepared hole which is cut by an owner in a hurry, where no resin is applied to seal the hole and the other is accidental, through damage (captain hits dock, dock tears up deck hardware etc.).

If it is a small area, you can drill and "whip" around the wet void, thereby sealing the wet area from the dry. If your area is larger, don't waste your time drilling a bunch of holes. You would save time by taking a circular saw to your deck, re-core then replace the deck panel. It all comes down to you and what your safety an/or comfort factor is and how they both work into your allotted time.

While I am blessed with having a balsa cored deck on my East Coast Triton (OK, Right Coast), I have been involved in a re-core on a buddy's Morgan OI (Out House) 41.

1) There, we drilled 3/16-1/4 inch holes about an inch apart. Use a bit with a depth adjustment (heck, wrap a piece of tape around the bit so you don't drill all the way through, only into the core.

2) Then we inserted a bent nail at 45 and 90 degrees to the deck. the nail is then attached to a power drill then you scramble the core.

3) Next you use a powerful shop vac to suck out all of the wet and dry core out through the little holes.

4) Mix your epoxy and use large hypo's to give your deck an epoxy shot, thus forcing the resin into the holes (you can mix resin with cab-o-sil or microballoons to give it some substance, but don't make it too thick or it won't flow).

5) Allow the resin to overflow through each to insure the fill and allow to cure (don't flatten your little domes yet)

6) Sand the little epoxy domes flush on your deck, prime and paint your deck.

7) It helps to do smaller sections at a time. Don't drill your entire deck, thinking that you will save time. A 2'x4' section is fine.

As far as hardware points go, I tend to over-drill to about three times the size of the mounting bolts, wet with epoxy the fill with epoxy (4-1 or 3-1) mixed with cab-o-sil to a near paste. After it cures, I sand, drill to size then bed, mount back then bolt. If you don't oversize the filler and rely only on the wetting of the core, compression from your hardware and backing plate can cause you to crack your new moisture barrier. The filler gives you a nice base to prevent this.

Don Tyson, #20

Trtion #20 had a bouncy deck which was one of the myriad items that "my enthusiasm overlooked" when I bought the boat. When I got the boat home 90 miles inland the interior remained dripping and wet. I slit the liner with my penknife and it bled sea water all over me. I had not a clue what lie ahead. After prodding around I determined that the entire deck was wet. Not just wet but full of the foulest water money could buy. To shorten the story let me say that the liner had been un-attached for so long that it was fatigued necessitating its complete removal. In case your wondering, it took 2-3 hours a night for more than a month, laying on my back grinding overhead until my arms couldn't take it. There is core in places you could not believe. I removed it all and ground it smooth. What a job!

I was going to install a new core from underneath but decided not to do so after inspecting the outside skin. I might add that this inspection was prompted by my crashing through the bridge deck because it was so badly fractured. The deck was

fractured everywhere it seemed. Every stanchion and fitting had spider cracks radiating from them, and the main hatchway was bad and the cockpit simply dangerous. I ground off all the gel coat on the outside and laminated the new core on top. I looks great. Many friends claim they can't tell the difference.

Being frugal and resourceful I intended to use cross-cut fir 2x4s to manufacture a homemade end grain product but realized that this would not bridge the cracks adequately. I settled on 3/8" fir underlayment from a local custom lumber store. Please don't shoot me but I planked the boat as original with epoxy saturated 2" x 2'-8' strips of this material and filled all cracks with pure resin. After sanding and filling I covered it with two layers of 4 oz cloth (45 degree). I assure you it all looks very good except that the gunel is not as high. I realize that I will probably have to re-do this in less than 39yrs but maybe I'll have more means then. If I'm careful to epoxy fill any mounting holes the core could last a long time.

I also replaced all berths and tabbing related items. The entire interior is essentially new construction. After ripping it apart I wouldn't give anyone a dime for that ice box. Junk. I keep ice a week in my coleman cooler when canoeing.

Larry Suter, #607, Dogstar

When that gorilla, Ray Alsup, ripped my starboard, rear lifeline stanchion nearly out of the deck early last May, I ground out a lot of the shattered fiberglass, tapered the edges so new stuff would have a large bonding area and put a large plywood backing plate underneath. Then I layed up new fiberglass back to the original level. The repaired stanchion area is better than new.

My point is that you can probably do some similar grinding, balsa removal and relaying of fiberglass around your stanchions. Replacing fiberglass is not a big deal and a good life-skill for a plastic boat owner.

Michael Smith, (INNISFREE, #683 ?)

Our Triton hasn't had a problem but I helped our son replace some stuff on an Alberg 35 and, previously, we did a Vanguard 32. We used exterior grade plywood. Think it's hardier than the balsa, a bit heavier (but that's o.k.), and when coated with epoxy before and during use certainly at least as water repellent. And easier to find and work with. On the crown of the cabin top on the Vanguard, we used two thin sheets to get the right bend. My point is, however, that it is easier to measure against what's there to get that thickness than get what it should be. In case the manufacturer used an odd lot or, for some reason, got something thicker or thinner than the norm.

In any event, it's a messy and somewhat stressful job (to make the first cut into the old deck especially). But an easy one, since little skill is required. Mike

Bernard Heise

Last year I ended up relaminating the side-decks of our boat, both of which had gotten wet. Even though the delamination covered a substantial area, I wasn't eager to perform the kind of major surgery involved in recoring. Instead I drilled lots of holes through the bottom laminate and injected slightly thickened epoxy into the voids. One reason I drilled the holes from the bottom was because I didn't want to mess up the appearance of the decks; another was that the bottom skin is quite thin compared to the top. Drilling holes in the bottom also made it easier for the decks to dry out--the water just dripped right out and I didn't have to worry about holes in the top letting new water in. Thus, freezing & expansion never became an issue.

The job turned out to be pretty tedious & time consuming but was not especially difficult. It took me two days of epoxy work per side-deck--after I finished the deck the first time, I tapped around in search of remaining voids & then drilled & expoxied again. It seems to have worked. The decks are still solid after an arduous sailing season.

George, #236 Ca Ira

The core material I used for #236 "Ca Ira" was 3/8" fabric backed end grain balsa. This size exactly matched what was already in there. I decided to go with balsa because it supposedly has much better adhesion properties than the foam or plastic based cores. In other words it won't separate from the top skin of the boat after a few years of flexing underfoot. I learned about this possibility from two different yards in the area. However, I have never read about any separation problems with the plastic cores so I don't know how true it is. Maybe it used to be true and that's why stuff like Nida Core was developed. Don't know. Anyway, part of my project was to totally isolate the core from any deck fittings, stanchion bases, chain plates, dodger attachment points, etc; so the type of core wouldn't matter. On my boat every single one of these items now goes through solid non-compressive epoxy and glass. My goal was to extend the solid glass areas 1/2" beyond anything going through it. For example, a chain plate would go through a rectangle of solid glass 2" by 1.25". Bolt holes were all 3/4" and 1" depending on the size of the bolt. This way the core would be forever isolated from anything that could cause a leak. I think there are some pictures of this work on the MIR. The one of the foredeck gives you a feel for what the finished bolt holes look like prior to drilling and painting.

Be ready for a project. After 40 years, "Ca Ira" had a total of 203 holes to be epoxy and glass filled. Also, If I were to do it again I would get a compressed air powered sander and a big air compressor. I burned out three large electric random orbit sanders re-doing the boat.

"How did you dig out the core under the glass to get out an inch?"

I believe you are talking about the areas around the chain plates? On "Ca Ira" this was easy because I had cut the top 1/4" fiberglass skin off the deck with a circular saw. The existing core was then chiseled out with a

wood chisel. Both skins were sanded with 60 grit. When I put in the new balsa core and epoxy I just left rectangular openings around the chain plates. Once the new core was in place, air release holes were drilled in

the top skin, everything was then gooped up with epoxy and West System adhesive filler (406) and the top skin was put back down. As soon as epoxy started to come out of the holes and the seams I would cover them with duct tape to keep all the epoxy from running out. Remember, there is a bit of camber to the deck so start taping the seams and holes nearest the toe rail first. Once everything was good and set in and there were no voids anywhere I taped up the most inboard seam. At this point everything is taped - all holes and the seam around the re-attached top piece of fiberglass skin. A couple days later, all the tape was removed and a 1/4" deep, 3" wide scoop was taken out of the seams with an angle grinder. Layers of 10oz and 6oz cloth were then layed in to build up the fiberglass skin on the seams. (you can see exactly what this looks like in the "Project Showcase" section of the MIR.) The strips of cloth start out thin and then get wider as the seam is built up - this way you finish with a flat surface. I then went around with the non compressive epoxy mixture( West system, 404 filler, bits of 10oz cloth )and filled in the holes, chain plate openings, etc. Sand, prime and paint. Nothing to it :-)

If I was just doing the area around the chain plates I would remove the chain plates and cut out the rectangle you want with a 1" drill bit or jigsaw. Then dig out a 1/2" of core around the hole you have made with a

small chisel or a filed down Allen wrench attached to a drill. This way the new epoxy has a large surface area of both balsa and fiberglass to bond to. Tape the bottom with duct tape. Fill with epoxy and fiberglass. Tape the top shut and let dry. Cut the new chain plate holes with a drill bit. Sand, prime, and paint. Attach the chain plates and bed with 3M 101. Once again, nothing to it :-)