: I am almost ready to glass my kayak. I will prefer do the coatings
: while the epoxy is still "green" to get a chemical
: bond, but i am not sure I can time it right. So maybe I will
: have to sand between the coats to get a mechanical bond instead.
: It will probably not be a problem between the seal coat and the
: first wet-out, but i am worried about sanding before the first
: fill coat. Won't this damage the glass?
: Also, will the epoxy have to be (almost) completely dry before I
: sand it, or can I do it as soon the green stage is over(where it
: can't be dented with a fingernail)?

: Palle Dam
: Denmark

I've used System Three epoxy for 25+ years and I aways liked the fact that you had
days to add new coats without having to sand.

I'm testing some MAS epoxy on the new boat and they say you must sand (rough it up a little)
after 12 hours or sooner if you can't press a fingerprint into the resin.

So, I'd say you need to find out what the epoxy manufacturer says about the resin/hardener you are using.

After the seal coat, it's easy to sand if you must. BUT after the glass wet-out your fiberglass cloth will be a
very rough texture and it is best if you can apply the first fill coat in the green resin re-coat window.

Then if you can't get to the next fill coat before it's time to sand, there is a much lower chance of hitting glass.

But, this sanding between coats is only to rough the surface and provide a "tooth" for the new resin, so go lightly.

Rob