Peeling hotcoat

[Jbrown69]

Hey so I shaped and glassed my first surfboard and now I'm having some issues with my hotcoat literally peeling off the board. Any ideas on why this happened and tips to resolve it? I feel weird riding the thing when I can feel the fiberglass cloth beneath the glassing even though the thing seems water tight

[oldmansurfer]

What kind of resin was the glassing done with? and the hot coat?

[Jbrown69]

I used epoxy in both circumstances

[oldmansurfer]

I don't think epoxy needs a hot coat. It just needs a sanding coat. Did you use the same resin and same mixture of part A and part B ? If there wasn't a difference then maybe you didn't clean off the resin after sanding and left a layer of dust?

[waikikikichan]

You should have wiped down the board with Denatured Alcohol before the hotcoat. You could have also sanded with 60 grit to give more a physical bond. But like OMS said you really don't need a hotcoat, unless you're using it as a filler and sand to blend the lam.

[oldmansurfer]

A hot coat is something Polyester resin needs because the glassing is done with a cooler mix meaning less catalyst added this makes the board less likely to shatter and leak but then needs a coat that has extra catalyst to harden the outer surface of the resin so it doesn't pressure ding to easily. They call it a hot coat because adding extra catalyst makes the resin get hot. Add too much and it will ignite