: Best soap? Whatever detergent is sitting on the kitchen sink. You're only
: washing any powder dust left from the wet sanding. If the epoxy was hard
: enough to sand you're OK. Generally a short week and it's no longer
: out-gassing.

I've been told to wait about a month or two between final epoxy and sand/varnish. The expoxy will slowly finish setting, adn in doing so will shrink a little. if you sand/varnish too soon you will start to see a little glass print-through on your varnish job.
just someone elses recycled $0.02