u/Puzzled-Community213

hello guys, I’m an artist mainly an sculptor and I’ve this stainless steel piece (a few small tubes side by side) and I want to paint only their tips (like a gradient that goes from metal to color) I have never used airbrush but I thought maybe it could be the way to go, but I don’t really know how to go about it, could you guys help me?

(I cant sand or use primers cause there is no clear starting point on the painted area since is going to be a small gradient area, but also is just a wall piece decoration thing so i dint think this would be a big problem)