I stripped down an entire bike and then rattle canned with a two part paint I got at an auto paint store. They said it would cure to a harder finish. I think you have to use it within 48 hours or so of having activated the can. As I recall, I did at least 3 primer coats and at least 3 top coats. I can’t remember if I did a clear coat. The paint seemed to hold up reasonably well for the year I had the bike before it was stolen and I was reasonably pleased with the results. I think I would be very hesitant though to try to combine my amateur, partial job with a professional job. Although, I did do the fork only on my black bike and that doesn’t clash with the old professional job too much. That was primer, one part black rattle can with a two part rattle clear coat. Hasn’t held up as well as I had hoped but it isn’t a disaster. My results did convince me not to try to do the rest of the bike.

For whatever it is worth, here in CA, the two part paint is marked for professional use only not for retail but the paint store sold it to me in my biking outfit without a word.