I know there is such a thing, our local AZ dosn't have it though.
Plus I had already applied normal primer.
Rustoleum says 200 deg F for the primer and normal Hammered. Which is pretty hot, but given that the T-stat dosn't open until 190F, I'm just not sure what the surface temp is, or what actually happens when you are close. I wouldn't expect it to boil off or anything, just wouldn't want it to get sticky and become messy.
But I'll trust the real-life experiences above and move on w/ life.