Epoxy filling stress cracks.

Barry

Barry

Paint Fanatic
Staff member
My vette when I was trying different intakes and carbs last year, the hood fell and hit the carb and did about a 6 inch shattering of paint and hood.

Sanded it down with 80 to glass to see damage and glass by all rights needed ground out and filled.

Had to do it, I brushed a coat of epoxy, ate dinner and an hour later brush another coat, I brushed because, I wanted it to soak the fibers.
Next morning before work I brushed a third coat.

Hand sanded smooth with 180 and have had car in sun for about four days, hood temp reached 148 one day, no stress or problems will be ready to paint over the fourth.
 
Barryk;21640 said:
Sanded it down with 80 to glass to see damage and glass by all rights needed ground out and filled.
Click to expand...

One of these days, I'm going to get around to restoring the factory fiberglass hardtop on my '65 MGB....there are some scratches through the original gelcoat, down to fiberglass. Should I take the whole thing down to glass, or can I rough up the remaining gelcoat, and epoxy prime the whole thing?

Never worked with fiberglass, and don't really know where to start.
 
I would just sand the glass with 80 and put about three wet coats of epoxy, let dry a week, sand with 180 smooth and put 2-3 more coats.
 
One thing for sure the SPI epoxy will stay flexible enough down the road that the cracks will never reappear.
 
I did an interesting test with epoxy primer awhile back, used fine filler sanding dust and added it to SPI epoxy then poured it a little over 1/8" thick and allowed it to cure. The test sample is still able to withstand a 90* bend test without cracking after 3 months but the cure was very slow at that thickness.
 
it took 3 years for my 3/4 inch hockey puck to get hard enough to crack. it was from doing the spi vette. it laid on the paint bench inside the booth.
 
Barryk;21673 said:
I would just sand the glass with 80 and put about three wet coats of epoxy, let dry a week, sand with 180 smooth and put 2-3 more coats.
Click to expand...

So get the remaining gelcoat off, or can it stay in place?
 
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