Maybe brush the initial coat, spray the finish coat. Mike Liston uses rustoleum self etching primer and rustoleum enamel. I was surprised, his engines look good. Apparently it is a good deal for what it costs.
Curious on how the color pigment holds ,to engine temperatures long term. Usually use a acryilic enamel stage, and three heavy coats. Seems to hold well. Last time ( rusty engine block), used a rust conversion Hammer Metal gun metal grey rattle can. Holding up well., so far.
