a fiber/resin ratio irony?

Im hoping someone can clear my head on something…

say you do youre final glassing and youre really good…your finished glass/resin ratio is about 1:1…

then when thats done, you lather the whole thing with a thick hotcoat filling in the holes in the weave, adding thickness to the outer shell, etc etc…

Doesnt hotcoating defeat the original purpose of having good glass/resin ratios???

Ironic isnt it?

But there’s one more thing: The hotcoat shouldn’t stay thick. I think the Aussie’s have the best discription of what a hotcoat should be. They call it a “Filler Coat”. Designed to fill in the weave of the lam coat. I know from experience that if the hotcoat is not sanded down, and remains thick, it can get some nasty rail to rail stress cracks when the board flexes.

Doug’s rule #1 to himself when glassing: Unreinforced resin is not strong.

Remember Gene Cooper’s description of glassing his boards? They lay an extra 4 oz. layer of cloth on the bottom, hotcoat it, then sand the hotcoat right down to the weave. Then they apply a thin gloss. Lots of fabric reinforced resin and only a little that’s not.


Yeah, it does in my opinion. That’s where vacuum has the advantage of not only pre-compressing the weave and reducing the ratio, but making it flatter as well.

I’m with Doug on this one. Vaccuuming is the ultimate way to get a high fiber to resin ratio, but lets face it folks we’re dealing with a couple thin layers of glass. It’s possible, with good technique, to improve over the typically, over the top, wet lay-up, common in boards. In my exerience wet lay-up can get within 4 oz. (weight) of a bagged board on a typical shorty with good technique (using epoxy). Hot coating is supposed to be fill, not excess.

In the old days the hot coat was done thick so the sand job was perfect so you could get that perfect gloss/finish. In high performance boards today, where strength to weight matters, resin ratio should be controlled.