Core Problems

Added 02/17/04

The 10.7 deck is cored with 6" x 6" x 3/8" thick plywood pieces. The curved sections of the cabin top are 3/8" end grain balsa. I'd be surprised if the 8.7 core specs are any different, as that would mean stocking several different thicknesses at the Columbia plant. Contact Justin Thompson and you should be able to get the complete laminate schedules, I have the ones for the 10.7.

Paul

Sidney, get in touch with Justinb Thompson (justin@sailinfo.com). He has the complete set of plans for the 8.7 and can supply you ith copies. You don't have to buy the lot, just about 8 or 9 will do. He'll e-mail; you the list of plans and you can choose the ones you want

john pampero iv (8.7)

Last summer I had to repair a small section of non-skid on the cabin roof that had been damaged. A buckle had smacked the area and dented right through to the unlerlying mat. The area was only a couple of square inches but I wanted to duplicate the pattern so that the repair would appear invisible after painting.

What I did was to make a plasticine "fence" around a good area that matched the damaged area for curvature. Using this good section I poured melted candle wax into my fenced area until I'd made up a good block of a couple of inches thick. After letting it cool, I removed the fence and popped off the wax block. Probably best to wait until night or very early in the morning before the sun can warm the wax. Now I had an exact mould of the non-skid pattern. Next, I froze the wax block, cleaned up the damaged area, mixed up some epoxy, spread it over, and pressed the wax block into it. Use a weight on the block while the epoxy cures. If you match the male bumps on the wax to the female dents in the non-skid then everything lines up perfectly. Well, in theory anyway. The mistake I made was to put a bit too much epoxy on the wound. I got a perfect reproduction but it was about 1/16" too high and I had to do some tricky carving and sanding. So if using this method you might want to experiment first. I removed the block by melting it away with boiling water but you should be able to remove it by popping it off.

Okay, I scraped the paint (many layers) (this boat has seen many colors!) off of the soft spot above portlight amidships. I believe the bad spot was caused when the PO over-tightened the grabrail causing an indention where water accumulated. The core is definitely wet (and presumably rotten). Anyway, the original gelcoat is cracked due to the flexing. (It is where one would naturally step up to approach the mast so it has to be repaired properly). My boat neighbor suggests removing the outer skin and rotten core, then filling the void with the Bondo product that contains fiberglass. West marine suggests filling with the West epoxy system. Fortunately, all of this is underneath what has been painted with anti-skid, so I don't think (If I do the job right) that there has to be much evidence of the surgery I am contemplating. I would like some comments from those who may have solved similar problems. S/V ForeverColumbia 8.7Mobile Bay, Alabama