Join Date: Oct 2004
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Wet Core Repair
I have had to deal with all of these problems and one, a 42'' centercockpit ketch, had only 3 square feet of balsa core that was NOT wet. Obviously, the job was done from above, as working from below would have meant dismantling far to much interior and it simply wasn''t an option. This is what we did:
We removed all deck hardware and equipment, then cut the entire non-skid area of the deck with a 1/2 exposed blade circular saw, leaving a 1" lip all around the edges both outboard and against the center cockpit. Then we carefully tore of the outer layer of glass and disposed of it. The core had maybe as many as 10,000 1/4" diameter West ''rods'' in it where previous attempts at repair had been made by laying pegboard on the deck and drilling holes through every hole in the pegboard into the deck, then injecting West and squeegeeing flush.
Good Lord. When the first thousand provide no improvement, why do people keep going? Anyway, you can''t saturate with West what is already saturated with water, and I mean saturated. We used standup barnacle scrapers (five feet long) to scrape off the basla and got soaked head to foot by how much water gushed out.
We had to be very careful no to step in the wrong places and cause damage to the inner liner. Next, detergent and scrub, again. Then big body grinders with 80Grit to smooth the surface, then begin the buildup.
Wipe down with acetone, then apply a mixture of West and colloidal silica with squeegees and set in place the first diagonal layer of 1/4" Luan cut into 2" strips and weighted down with many small weights to apply pressure and hold the right shape. By the time we made it to the back, start the second layer from the front, opposite diagonal with thinner West and now using Monel staples. Third layer went of side to side, then fair and grind.
Next, three layers of 1808 Biaxial fabmat with West, smooth and fair, seal with Interlux 1000 then 2000 barrier coat, Awlgrip White, then light gray with non-skid.
25,000 and a bargain, considering all the work and materials. The deck is solid as a rock and the owner is delighted, though sincerely wishing he hadn''t spent the first ten grand having people drill holes and fill.
I know this was long-winded, but the method works well. You can substitute door-skin to come up with a thinner laminate, but the beauty of those materials is that they are virtually flawless, inexpensive, far superior as a deck core to balsa, which DOES NOT deter water migration which was once thought, and it is as easy to fit as anyone with a sheetrock knife can tell you. Score and pop as you go.