Need fiberglass advice

[shockwave538]

I have a specific question, separate from my out of date build thread. I had to refoam the tray on my SN. I got the I initial part done, and filled the tray with a combination of block and poured foam.

I started the reassembly by glueing in the original tray pieces with a thin layer of poured foam underneath, since that crap seems pretty adhesive.

The plan was to use the original bottom and side pieces, then use new glass to finish the seams and hold everything I place. I’m now wondering if that will be strong/secure enough to hold everything in place without cracking or forming interior gaps. Should I instead remove the original pieces and finish the entire tray with fresh glass? (If so, I might just cut more and widen it.) I am fairly new with the fabrication dept and would like some advice, preferably from some folks who’ve been around the block and can give an experienced opinion. Thanks.

 

[Big Kahuna]

you can use the old sections as long as you get a good bond. I would lay a sheet of glass over it all once you get it stripped in.

 

[shockwave538]

you can use the old sections as long as you get a good bond.

Are you talking about the bond to the foam or the adjacent hull?

Something else I forgot to mention is while the side panels were sitting out, they detensioned and got a little inward curve to them, so they don’t sit flush with the underlying foam. I can get it so the center of the panel is flush and the corners sink in a little deeper (not much, 1/4” at most), and just have a little extra to fill in around the corners to make it all even.

Does this sound ok, or should I redo the side panels with fresh glass to be safe? The bottom kept its original shape and fit just right, so I was thinking that piece should be just fine.

 

[shockwave538]

Finally found a picture of it. If you look close, you can see where the corners sink in a little, but not a lot. (I also beveled all the edges to allow for stronger glass work) The whole piece felt like it wanted to flex when pushed. I put the poured foam down underneath and put lots of pressure on top to adhere it and hopefully keep it in place nice and solid.

 

[Carrera911]

My corners wanted to sink in like that too so I cut up shims from the insulation foam that would only let it sink in as far as it needs to. Then I used whatever I had laying around to push all the edges in flat and flush (clamps, duct tape, 2x4 cut to length etc.). I'd pick out all that foam in the seams and clean off as much of the residue as possible. Thicken some epoxy with cabosil, micro balloons or talc, and smear it in all the seams. Sand down the seams once it cures and grind off all the gelcoat in the middle of your tray. I added 3 layers of 1708 on the floor and 1 layer 1208 up the gunwales. 3 layers might be a bit overkill but I did that because my old tray was pretty trashed. I would still say to do at least 2 though. I went through all this a couple months ago and explained things better w/ pics in my build page if you're interested.