Hi there. So my day job is metal finishing for aerospace, painting specifically.
Finally a thread where I feel useful lol
So there are 2 kinds of adhesion basically, chemical and mechanical.
I shoot for both of those on sabers when possible. Of course chemical will be a primer, and mechanical can be as simple as scuffing the surface up a bit.
On sabers I use this:
Dupli-Color CP199 Clear Adhesion Promoter Primer - 11 oz. by Dupli-Color Amazon.com: Dupli-Color CP199 Clear Adhesion Promoter Primer - 11 oz. by Dupli-Color: Home Improvement
The main benefit being, it’s clear. It works fairly good on aluminum too which is nice.
Before you paint, maybe try and scuff up the area with scotch brite at a minimum.
If the paint I’m applying is opaque I’ll prep the part with 400 sandpaper. Always sand in circles, so you don’t leave gouges or scratches
After that and a light coat of primer, whatever you spray should do fine. Light coats.
I feel like I’m giving more info than was asked for, so I’ll stop there. I’m happy to help anytime.