Gel/Resin Mix

I've found if I add about 20-30% white gelcoat to a batch of poly resin, it blends well to a solid white. I haven't tried a lower % yet, but I'll bet it will work.

US Composites standard white gelcoat and the 435 poly resin.

It looks like gelcoat when cured, but probably wouldn't polish up like gel.

How strong is gelcoat as a layup resin? How strong's my mix? I'm just playing around with it rebuilding an engine housing....

Re: Gel/Resin Mix

There's no problem mixing most resins and gel coats, it just depends on what you want to do. It can be difficult to laminate with a pigmeneted resin because you can't see if the glass is wet out completely, or if the air has been rolled out. Plus as you add resin to gel coat the UV resistance drops, so it will typically discolor, or turn yellow sooner. I do at times add gel coat to resin though, in small repairs adding gel coat to the resin can help eliminate the darker resin showing through the gel coat if you happen to sand on it a little too much.

I do it sometimes when glassing a floor, this way if you add sand while it's still wet you only need a single layer of gel coat over the top and if it wears down, the color stays the same all the way through.