paint adhesion to chrome grills
Thread Starter
Instructor
Joined: Mar 2011
Posts: 127
Likes: 2
paint adhesion to chrome grills
I'm restoring my front grills on my 70 coupe. I had them rechromed and now I'm painting them. The side louvers had a paint base of some sort from the factory that was supper stout and hard to remove with chemical stripper. I used a metal etching primer but the paint is not adhering very well regardless. Any suggestions on what to do to get the paint to stick?
Burning Brakes
Joined: Aug 2011
Posts: 983
Likes: 35
From: Redding California
As destructive as it sounds, you're going to have to take a 40 grit grinding disc or flap wheel on a grinder and go at the chrome to make an area for the primer to "bite" into. There's a ton of YouTube videos on prepping bare metal for etching or epoxy primer and you need to do pretty much the same prep. Chrome is not a porous surface and a light scuff with some sand paper by hand isn't going to do much good. Don't be deceived by the word "etch" in etching primer. It doesn't make a magical bond to metal. It still needs something to grip to. It's more of a rust preventative thing. Don't worry about the scratches you're going to put into it. After a good prime, you can sand the scratches out. Good luck with your project!
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If you clean the chrome surface really well with a volatile cleaner (lacquer thinner), then mask and shoot with a decent paint, it should stick and stay fine...after curing for 5 days or so!!
Paint...even though it appears to be 'dry' is very fragile for the first day or two. And, it will cure and harden even more for several more days. Most folks don't want to wait that long, and they mess with it way too soon.
I painted the gray/cast-iron color on my grillwork and chrome surround parts years ago without any primer and they are holding up just fine.
Paint...even though it appears to be 'dry' is very fragile for the first day or two. And, it will cure and harden even more for several more days. Most folks don't want to wait that long, and they mess with it way too soon.
I painted the gray/cast-iron color on my grillwork and chrome surround parts years ago without any primer and they are holding up just fine.
Safety Car
Joined: Feb 2012
Posts: 4,705
Likes: 983
From: Orlando FL
Team Owner
Joined: Sep 2006
Posts: 31,267
Likes: 4,361
From: Westminster Maryland
Hi,
I too haven't had a problem with paint adhering to the FRONT grills.
I also agree that 40 grit is pretty aggressive to use and would shy away from it.
I think you're adhesion problems may be the result of the remains of what the chrome shop used to polish the grills when they were completed.
I think cleaning them with lacquer thinner as 7T1 suggests may be a good thing to try.
Regards,
Alan
ogto shows the SIDE grills which I do think benefit from sanding with something like 220, but only on the large flat vertical panel surfaces of each grill.
I too haven't had a problem with paint adhering to the FRONT grills.
I also agree that 40 grit is pretty aggressive to use and would shy away from it.
I think you're adhesion problems may be the result of the remains of what the chrome shop used to polish the grills when they were completed.
I think cleaning them with lacquer thinner as 7T1 suggests may be a good thing to try.
Regards,
Alan
ogto shows the SIDE grills which I do think benefit from sanding with something like 220, but only on the large flat vertical panel surfaces of each grill.
Race Director
Joined: Jun 2005
Posts: 10,189
Likes: 206
2018 Corvette of Year Finalist
2017 C3 of Year
Not sure if the product is still available but OEM Paints used to sell a pre adhesive spray to be applied before the actual paint. It went on clear. I used the product on the bumperettes and lower front bumper chrome areas. It worked great! 
I was also able to purchase their "dark grey matte finish" paint for the bumperette/bumpers. It was a perfect match to the factory applied material. I had extra and sold it to a fellow in California.........
Contact them:
http://www.oempaints.com/
Edit: It was big $$$$!
I was also able to purchase their "dark grey matte finish" paint for the bumperette/bumpers. It was a perfect match to the factory applied material. I had extra and sold it to a fellow in California.........
Contact them:
http://www.oempaints.com/
Edit: It was big $$$$!
Advanced
Joined: Feb 2015
Posts: 55
Likes: 0
front grill paint
Duplicolor sells an adhesion promoter that's supposed to work with chrome/metal. I plan to use it this week to prepare my lower grills for paint. Does anyone know if Duplicolor or anyone else has a good match for that grey/graphite color?
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Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
I selected a "cast iron" gray paint. It may have come out just slightly lighter than the original color...but not by much.
P.S. You should be aware that the dark gray, flat-colored paint used on the center grill section of the 70-71 cars was NOT the same color as what was used on the painted areas over the chrome pieces.
P.S. You should be aware that the dark gray, flat-colored paint used on the center grill section of the 70-71 cars was NOT the same color as what was used on the painted areas over the chrome pieces.