Gordon wrote:

I just rescued an old O'day 20 and decided to clean up the oxidized
looking hull. That's when I realized the boat had been painted and I wasn't
trying to clean gelcoat.
Apparently it is epoxy and is HARD. So. how do I clean it up? Wet sand?
Heavy duty rubbing compound doesn't touch it!

If it's epoxy paint or LPU, it shouldn't look oxidized.
Something funny going on here.

When you say "heavy duty rubbing compound won't touch it"
what is happening? What grit? Are you using a buffer?

You might try wetsanding a small area, using an orbital
sander. If that takes the "oxidation" off then jump to the
next higher grit (I'd start with 1000), then try buffing &
waxing.

Another thing to try is Poly-Glo remover. Some of these
chemical glops that make the hull shine & look new end up
looking like crap after a few years, and they're a PITA to
get off unless you have the right remover.

Fresh Breezes- Doug King