I always fill the weave within 48 hours of glassing and with successive coats within 48 hours of each other and a light sanding (only enough to take off the resin sitting on top of the fibers and not sanding into the fibers) between each application till the weave is filled. The reason is that the resin stays green for at least 48 hours (the manufacturers of the resin says 72 hours). An amine blush developes after this and you can't get it out from between each of the spaces in the weave of the cloth even with chemicals and scotch bright (at least I don't believe you can). The amine blush will hinder the bond.

: Hello fellow enthusiasts.

: Since my motivation and time are limited and its generally over 100 degrees
: here in Phoenix - and I am working outside (which is actually cooler than
: my garage!) - I now have a kayak which is 100% covered with fiberglass -
: but none of the weave has been filled. At this point - I'm not going to
: get a chemical bond with the next coat of epoxy - in fact I have already
: sanded lightly and feathered where necessary.

: So here is the question: I'm dying to get to the woodworking fun of building
: the cockpit coaming and rim. I'm planning to 'glass over the coaming when
: it is complete. Is there any reason to fill the weave now? Can I do it at
: the end when the cockpit is done and 'glassed? It seems like it would save
: time - since I'm going to have to feather the coaming 'glass into the deck
: anyway.

: Advice? Comments?

: Thanks in advance, PC