As far as sanding the seal coat, do not do this without a resprirator. The green epoxy dust is quite toxic. I use a scraper (Sharpened handled paint scraper with the corners rounded) to smooth and remove drips.

: Just a quick question regarding the use of epoxy for fillets, gap
: filling, etc. I'm assuming that when you use epoxy for fillets
: and such that it's "hardened". Is this correct, and if
: so, is there ever an instance where you would use only the resin
: with no hardner mixed in? While I'm on the subject of epoxy,
: should I sand the sealer coat before I lay on the fiberglass
: cloth? Thanks.