I've built several tube chassis cars and painted most with automotive paint. I've also had them powder coated. The best paint I've found that holds up to road hazards is the Eastwood chassis paint. But powder coat is more durable than any paint I've found yet.


But here's the biggest issue for me. Painting a tube chassis is a PITA like you can't imagine until you try it. Trying to get even coverage is difficult and if you start on the inner tubes you will get over-spray on them when you spray the outer tubes and ruin the gloss finish. If you start on the outer tubes you will lean on the fresh paint on the outer tubes when you try t reach across to paint the inner tubes. And you will get over-spray on the outer tubes anyway. Most of your paint will end up on the shop floor so you must buy more paint than what you expect you need. And I use a chassis rotisserie, if trying to paint a chassis without one you are going to struggle 10 times more.

So from my experience, powder coating is the best, easiest, and lest expensive way to coat a chassis.