I did my plenum and water pipes with the black wrinkle! Words of advice are put even layers and let it dry at least 3 days before you mess with it! I thought my pipes were dry so I went to put them on and the paint just slid I guess you could say.... So I had to repaint em.... One thicker coat then 2-3 light even coats is what I did on my plenum! Some spots didn't have as much "wrinkle" so I went back and sprayed the spots that lacked wrinkle and it helped some..