[misteryu]

Hello,

I sprayed 2k over some quarter panels and in the jambs while there was some bare metal prob 7 inches by 1/2 inch wide vertically in the jamb. I read on the tech sheet that it could cover bare metal but not for large areas. Well i tried it and whiel wetsanding i sanded through where the metal was. Well i started to scrape it off pretty easily where the metal was so i sanded the 2k off in that area.

I've decided i want to spray some epoxy on those bare metal spots, then 2k.

Well my question is, is it ok to spray epoxy over 2k? It's not going to be large, i guess the 2k will lightly coat on the surrounding bare metal where the 2k is. Any info would be greatly appreciated. Thanks

Chris

[julmer]

Just happened to have the PPG site open. Here's the poop on Onmi epoxy primer

Cleaned and sanded steel, galvanized, aluminum,
fiberglass, old finishes, and body filler.
MP176 Etch Primer
MP178 Plastic Primer
MP181 1K Primer Surfacer
MP182 2K Urethane Surfacer
MP184 Compliant Surfacer
MX198 Polyester Primer
MP210 1K High Solids Primer
MP211 2K High Solids Primer

Looks like it is happy over almost any othe rprimer.

[BarryK]

Originally posted by julmer
Just happened to have the PPG site open. Here's the poop on Onmi epoxy primer

Cleaned and sanded steel, galvanized, aluminum,
fiberglass, old finishes, and body filler.
MP176 Etch Primer
MP178 Plastic Primer
MP181 1K Primer Surfacer
MP182 2K Urethane Surfacer
MP184 Compliant Surfacer
MX198 Polyester Primer
MP210 1K High Solids Primer
MP211 2K High Solids Primer

Looks like it is happy over almost any othe rprimer.

*************************************************
Epoxies can go over anything like he pointed out.
2k primer adhesion to bare metal? Some companies say don't some say for small spots.
2K's stick very well to bare metal but have very poor corrosion resistance, so if there is any contaminates at all or metal has set for a week or so the primer will not have good adhesion as you found out.
Ideal situation for 2K over bare metal is you just DA'd through the paint and are going to primer right away, such as a dealership warranty repair.

[misteryu]

Thanks guys,


Could the reason why it didn't stick well is b/c i didn't scuff it with anything courser than 180?? Should it be scuffed with 80 before i shoot my epoxy or is it ok to just prime right over it?

THanks

[BarryK]

Thats a tough one! By rights it should stick to 180 as good as 80 because of the positive charge of the resin.

When I write a tech sheet for bare metal I say prep bare metal with 80-180. (The finer grits started with the European paint companies)

Myself, I have never used anything finer than 80 grit on raw metal or aluminum.

If nothing else using an 80 grit just makes me feel better.