Paint wouldn't stick to the grille?

[ambitions2]

Friend has a '93 Jimmy that he was in an accident with.  I found him a grille in good shape at the junkyard, but needed some cleaning up.  So I decided to scuff the grille with 120 grit paper and rattle canned the "chrome pieces" of the grill (not actually chrome, but painted chrome I think.  These are the parts around the actual grille fins - see picture below).  I then taped off the freshly painted area (1 week later), scuffed and painted the actual grilles black.  I was peeling off the tape and the chrome paint started to come up.  I was so amazed that I rubbed my finger on the chrome paint and it came up like nothing and I could see the scuffed area.  However the black paint was fine and was not coming up at all.

The piece has sat for 2 weeks so it had enough time to cure and tack.  After painting it chrome I left it for 1 week to tack and cure and then started the black. 
After I scuffed each piece I wiped it down with natural alcohol and let it dry. 
Both cans of paint are from Rustolem.

Am I missing something here?   

http://www.edmunds.com/pictures/VEHICLE/1993/Chevrolet/13329/1993.chevrolet.s10blazer.1872-396x249.jpg

[MEK-Dangerfield]

I would have used a self-etching primer befote the paint. I know Eastwood sells it in rattle can form.


  Mike

[Bullitt-]

If I understand correctly the entire grille was "chrome"  & the black paint stuck, if that's the case remove the chrome paint, repaint the entire grille black & then tape off & put chrome paint where you want it.

[ambitions2]

@ MEK: Your thinking the paint did not have anything to grip too?  If I use the self-etching primer and hit that lightly then the paint should stick to the primer?

@ Bullit: The only place I painted the grille black was the actual grille fins (I attached the picture because I had some trouble explaining it).  Expect for the fins everything else is "chrome" and these were the only places the paint came up.

Now that I think about it, I probably should have primed the whole grill and then rattle canned it because that would have given the paint something to stick too.  Am I close on this?

[MEK-Dangerfield]

@ MEK: Your thinking the paint did not have anything to grip too?  If I use the self-etching primer and hit that lightly then the paint should stick to the primer?

Yes, that's what I'm thinking.

[ambitions2]

Thanks MEK.  Looks like on my lunch break I will be heading to Home Depot. 

[craigsmytcudas]

you can use automotive grade paints from autozone . use trim paint green cans by krylon, also the tunner guys dye everything and use whats called bull dog adhesion promoter it turns purple after a short dry time then you can use just about any thing on it . its used in body shops for bumper covers before prime or color ,also the silver  you used might have some directions on the can .c

[ChallengerGary]

Bull Dog is great stuff.  I've used it several times throughout the years.  It also works well on things like undercarriages and engine compartments in nooks and crannies where you cannot sand too easily.