I am looking to topcoat an epoxy repair. What do I have to do to prep? and what do prime with? I have bought a quart of gel...should I use this or is the a urethane paint I should use?

Paint over epoxy.

is your final surface epoxy and glass or an epoxy fairing filler?

That is part of the question too...what do I use for the fairing filler?

Cass Polymers 861 is really good stuff, spreads like cake frosting and sands great.

http://www.adtechplastics.com/pc-86-...air-resin.aspx

If the final faired 861 surface is a little porous you can brush on a hot coat of just epoxy resin to clean up the surface then lightly re sand after a couple days curing. From there i just use a high build 2K primer.

After the primer I can top coat with anything? What did you touchup my boat with? I have white gel on the shelf at home.

yes you can topcoat with any automotive system. I did your boat with a single stage urethane I think.