I'm curious. I have a "35" Ford chopped sedan and it's painted with "Flat Black" epoxy primer. I like the look for now, however here's the rub. How do you keep the finish looking good? I know there are plenty of HRs on HAMB with flat black paint and most of them look cleaner and nicer then mine. I only ask because we are headed to the "Good Guys" in Nashville soon and I'd like a better look. What am I missing?
I guess you are missing the search function? Steel wool and elbo grease. Here's the rub you either wax one or steel wool one both take a lot of work to keep looking pristine. Or you could just forget about it and go and have a good time. If it aint fun there is no reason to do it.
Why not paint it with a flat paint? Or, you can use clear top coat with a flattening agent over the primer to keep it nice. Primer was never really meant as a top coat and it will suck up moisture like a sponge, holding it against the sheet metal. It will also fade a lot faster than paint will, especially if not top-coated. In your case, hit the primer with a 600 or 800 grit to knock it down to an even appearance. Unless you cover it with something, you will have to do this again, and you will eventually get to the point that you'll burn through the primer in spots.
Epoxy isn't UV stable so it will "chalk up" after a while, it needs topcoating. Although, my trailer lived outside in bare black epoxy and it did take a couple of years, but started going chalky white sure enough. Current car is 2k satin (though is being changed). It keeps OK with a wash, have to wipe most water off or tidemarks etc show.
My buddy has the same black epoxy finish on his Tee sedan -He cleans it with spray-on quick detailer(like Mothers) and a rag-has been cleaning it this way for 5 years and looks great
Epoxy primer won't allow water to penetrate, so that's not a problem. Skcollob is right-it'll chalk up because of UV.