I have used this stuff and it works great as long as there is NOOO paint at all under it! I also sugest using an acid primer. When I used it I had no brush stokes butthe key is to not keep brushing it. Get it on and stay away from that area until its dry or if you are putting a second coat on you have to do it when its slightly tacky! My brother is using por-15 in his engine compartment. I'll let you know how it went when its done but it might not be for awhile. It also really tuff to sand! I like the stuff but I also have been going with eastwoods stuff so I can sand and topcoat it.