I'm doing a full frame off restoration on a '68 Deuce. I have found the Behr Marquee I am using very soft, dings easily even up to two weeks after painting. I'm assuming it will take the full 8 weeks to harden properly and getting the painted parts out in the sun to cure for full durability, however this has concerned me. What I have found that has worked really well for me is using a cheap Wagner old school power sprayer (airless), thinning the paint with water approx. 1 ounce per quart. Paint flows nicely and looks really good. Any more water than that you risk runs, any less you risk a textured look. So far so good, the only issue I'm concerned about is the hardness of the paint. My primary question is, if you paint the exhaust stack with Behr latex paint, will it hold up or cook off due to extreme heat?