You use rustoleum primer too? Only reason why I'm asking, is im a fan of rusto matte colors [I add gloss through my clear] and It seems like either im doing something REALLY wrong or the paints coming off. I live in humid area, things tend to take longer to dry.
but I ALWAYS have an issue with rusto primer and color.. For example. Paint a piece of freshly cleaned sheet steel, the whole nine yards, sand, degrease, delint, spray the primer. Let the primer cure, because I normally sand it down and spray another coat, and let that cure [24 hours for "cure"] then spray my color, and clear following normal directions. but I always have bonding issues between the color and the primer, the paint will chip off in little chips with zero warning. maybe a mm across in size, leaving the primer just fine underneath NEVER takes the primer with it. I assume its bad bonding.. but I don't know maybe I am doing something wrong..
but I've been in the spray paint game for years now myself.. I know pretty much what I can and cant mix from things off the shelf. for a really good looking finish. this primer issue has come about with my motorcycle gas tank mainly and some other stuff.
Rusto Primer
Rusto Matte color
Minwax Helmsman Spar Urethane - gloss
I tested it before hand following the same directions but I did it on a small piece and it never chipped like this because it just saw "lab" test not real world.. but I soaked the SOB in 98 octane gasoline for 3 days straight and it never lifted or peeled and I wacked it with a hammer for flexibility testing, and it didn't flake or chip like the paint had lost its stretch. [**** yeah that spar urethane stuff is the strength of it all.]
For indoor stuff that isn't wood and I just want it painted with decent durability, lets assume like a metal PC case or something along those lines.
Krylon primer.
Rusto Matte color
Krylon crystal clear acrylic [actually starting to get hard to find for some weird reason.]
Never had a problem with those. Ever.. and has pretty decent durability despite the whole "acrylic clear over enamel color" it deals with heat pretty darn well within a reasonable factor. and doesn't yellow in sunlight.
Oh and while I'm fanboying over paint.
POR15 for all your in-da-gastank needs...
And any quality truck bed liner junk you can find for spraying inside wheel wells, underneath your junker car to keep it from rusting. underneath a gokart to protect it from rocks and sand and sticks.