Thread: Polyester/epoxy compatability

I've done some more research, it seems that my best interests are to use epoxy, for many reasons. For the false floor locating strips, I'll seal the back of the strip in epoxy and let it cure, then epoxy the strip to the inside wall of the cavity (cleaned fibreglass) and screw along its length, then once cured, remove the screws and plug screw holes with epoxy, and then seal the strip along its length with epoxy. How does this sound?

As for the forward floor section with holes cut out, i'll let it all dry out, clean up the holes with sandpaper, and then coat exposed grain with epoxy.

Does this sound like I am on the right track?

Chris

Originally Posted by Ricochet

Does this sound like I am on the right track?

Chris

Yep, I would use epoxy. It bonds better to wood than polyseter ever did.

No worries with comaptabiltiy either. Epoxy will bond to cured polyseter OK.

Note though that the reverse is not true - polyseter resin won't bond to cured epoxy, not that you would ever want to do this anyway.

It is very important to seal off exposed end-grain of cut timber. This is where most rot gets in. Epoxy is good stuff. Go for it.

Cheers, Cameron.

Thanks very much for that Cameron, really appreciate it! Here are some pics of what I found-

It started with water in the bilge, due to boatyard leaving transom bung in and some rain here in Perth. Brought her home and let her drain, but i wanted to further inspect, as when the boat was retrimmed, all floor spaces were sealed off by carpet being glued down.

I cut the carpet out and found the fuel tank and 30 years of rubbish and muck below




I cleaned all this out, and found a few things. All limber holes in frames were blocked with rubbish and gunk, but the midships frame had been purposely blocked with wine corks.



I wanted to get access to the sealed floor around the helm, as i was sure there was nasty things below. I bit the bullet and cut inspection holes with a holesaw, and worked my way up the floor. There was a lot of rubbish under there also, that was blocking the limber holes in the frame immediately aft.








You can see in the last pic that the floor extends into the V-berth. I was thinking about doing the same for the V-berth floor, but there is no frame below it, so all the rubbish would have washed back to the helm floor. The ply floor at the helm was in good condition, no rot or soft spots, but it doesn't seem to be sealed on the underside of the ply. Glass strand mat and resin on top, bare ply underside. Needless to say will be keeping a close eye on this cavity and keeping it well ventilated.

Chris

Chris, you seem to have things well in hand. Unfortunately, you are experiencing what many have with older production boats.

I'm surprised you have any limber holes at all in the sole support framing. It's common for them not to have any. You are very correct in that the weeps (limbers) need to be cleaned out and placed where necessary. You can't have too many, but you sure can have too few.

Typically, they sealed up the under sole area by tabbing the sole to the hull shell and leaving the support structure out of sight, out of mind. This works until the boat is out of warranty, at which point they don't care any more.

The best thing you can do is provide a path for any accumulated moisture to drain aft. This usually means lots of weep holes and modifying the framing a little. Also consider some plywood "bilge hatches" so you can uncover these contained areas and vent them, when the boat is parked. Naturally, park her bow high so she can drain aft to the transom plugs.

With the plywood uncoated, it'll go soft eventually, unless very well ventilated (as you know). Replacing a sole is a pain in the butt, but not as hard as it would seem. Since you seem to have caught this before the sole feels like your walking around on a mattress, you have a shot at preventing it from rotting out.

Carpet has killed many a boat. Don't use it if you can avoid it, unless it on a purely 'glass piece. If it's on a plywood part, even covered with 'glass, it will eventually rot the plywood, from trapped moisture. If it wasn't for carpet in boats, I'd have lost 50% of my repair business. So, I'm hoping the word doesn't get out to the manufactures, so keep this secret for me, will 'ya.