It is a paint. It costs $120 per quart. I bought a quart several years ago and have done several sets of manifolds. There is probably enough left for two more sets. So $120 and I get 6 sets of manifolds; not bad. I spray on one medium wet coat and a few minutes later another medium wet coat. They warn you to NOT spray a second coat after the first dries, and to NOT build up too many coats. You could use just about any spray gun, even a cheap Harbor Freight one. Like I said, all of my customers have always been very pleased.
I have never used the Techline on headers. However, about 25 years ago, I used the silver Eastwood stuff on the headers on my Barracuda. It looked pretty good and lasted for several years before needing a bit of touchup. THAT BEING SAID, I really like the Techline stuff, and it's all I'll use on manifolds.
Agreed. I sprayed mine on the first time and brushed on the touchup.