Ira Donovan

Topic: Paint Adhesion Problems during repair

Hi all,

Most know me, but I am inquiring into an issue that I have limited proof and data in addressing.  Most autos are processed through a coating process during manufacture, most likely ecoating.  I have a client that had an "accident" where a vehicle backed into a door panel.  the door panel was replaced and panel "blended in."  Apparently, the hood and bumper was also replaced in the repair. 

There are now paint adhesion issue on the bumper for which the dealer claims they are "rock chips."  Obviously, I can tell the difference, but does anyone have any data on the adhesion requirements for Saturn or other GM products.  I do not have any specs, but if I had a QA\QC reference, I could perform a tape adhesion test to prove that the issue is an adhesion issue and not an impact issue.

Any help is appreciated.

Thanks,

Ira

Ira Donovan's Website

DustinGebhardt

Re: Paint Adhesion Problems during repair

While I don't have the actual spec, doing a Google search came up with this spec:


GMNA GM4350M - Painted Part Performance Requirements


I would assume that this spec would cover your question.  If the bumper is plastic, this line may apply:

"For painted plastic parts only, the combinations of substrate, surface
preparation and applied paints shall use that which are shown in GM
Approved Paint on Parts Systems (APOPS) database. When APOPS testing is
performed each test must be completed on a minimum of three (3)
samples, each obtained from separate parts."


So you may be able to go to the guy that did the touch up and ask to see his proof that his paint, equipment, and pretreatment are all APOPS certified.

-Dustin Gebhardt, CEF

Advanced Manufacturing/Finishing Engineer

Moen

Sanford, NC

Ira Donovan

Re: Paint Adhesion Problems during repair

Dustin,

Does the spec reference any tape spec?  For example 200 PSI, which is common for some aerospace applications.  I can order tape from 3M if I knew the specific requirement, as I am sure they did not do any testing on the repaired portion.

I am knida looking forward to the look on the guys face when I do the test in front of him.  If I was mean, I would ask him if I could do it on one of his new cars, but the liability is too great.  So, just looking for the ammo to make my case.

Thanks for the info provided though.

Ira

Ira Donovan's Website

DustinGebhardt

Re: Paint Adhesion Problems during repair

I couldn't tell you about the actual contents of the spec.  I searched around, but I could not find the spec for free anywhere.  Let's hope that somebody on this forum can enlighten us.

-Dustin Gebhardt, CEF

Advanced Manufacturing/Finishing Engineer

Moen

Sanford, NC