: The plan was to wet sand the epoxy with 180 and then 220 and finish
: with the McClosky Spar Varnish (which I bought when I should
: have finished it previously). Any gotchas that I should be
: looking for?

Sounds like a good plan to me.
Perhaps best to leave the soap out of the wet sanding water, if that is your habit.

From Gougeon/WEST epoxy:
http://www.westsystem.com/ss/assets/Uploads/Ew20Contamination.pdf

"Amine blush may be formed when epoxy
cures. Amine blush is water soluble. Many organic solvents are completely ineffective for
removing it. That is why we suggest washing
an epoxy surface with water (water clean
enough to drink) using a Scotch Brite™ pad
(or wet sanding with waterproof wet/dry
sandpaper) and drying it with paper towels
before continuing with another operation.
Soapy water, or water with ammonia or
bleach, is not necessary and may leave a residue—another possible surface contamination."

Amine blush is more of an issue with getting epoxy to bond to the contaminated surface, but it certainly won't do your varnish job any good.
For varnishing: thin coats, not thick are best.