#1  
Old 05-14-2020, 05:34 PM
Tomaso Tomaso is offline
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Default What would cause paint to flake/peel?

Just curious on what would cause the old paint to flake off or peel like on a large area too and large flakes. But the red primer stays intact? I’m just curious...

I don’t want to do a show finish on the paint yet. I just want to fix the area, but make sure it doesn’t do that again any time soon.. It’s weird because it looks like the primer hasn’t lifted and is flat/smooth...

I’m going to sand it down, if it goes to metal, I’ll respray primer, sand it smooth, then paint. But would anything cause it to lift again in another spot? If I sand the other area to blend it in?

I just want a temporary fix for now..

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Old 05-14-2020, 07:14 PM
Chief of the 60's Chief of the 60's is offline
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Its called "delam", short for delamination. Causes vary and there are many. GM had major issues with delam in the late 80's and 90's. Go into a Pontiac dealership's body shop during that period and watch them take a blow gun to strip a new Grand Prix's paint.

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Old 05-14-2020, 07:29 PM
Tomaso Tomaso is offline
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That's it alright. Looked it up. So it's basically a gamble if I feather out and repaint over it.
So it looks like a bigger project now.

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Old 05-14-2020, 07:49 PM
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You didn't mention the age of the car, or if this is the original paint, but if it's from the early 1990s that's when the auto manufacturers were switching over to water base paint. GM, Ford and Chrysler (as well as the foreign brands) all had issues to some extent with poor adhesion, and it took them a few years to get things figured out.

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Old 05-14-2020, 07:52 PM
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It's a 1966. But It was repainted who knows when... A lot of panels have what looks like that delam. You can either peel it off or chip it off.

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Old 05-14-2020, 08:45 PM
MUSLCAH MUSLCAH is offline
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Use a razor blade and a blow gun..to get that paint off. If you just want to booger it up...with out getting into it...just use a skim coat of body filler on the broken edges....prime and paint. I did a guys 2004 Chevy van...just the nose and Windsheild pillars...flaking here and there...just did the filler thing and painted....still holding up 3 years later...lol

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Old 05-14-2020, 08:48 PM
Chief of the 60's Chief of the 60's is offline
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Don't try to feather it. I have a car now with masking tape alone removed the paint. If you paint over it, you will be doing it again and the second time will not be as easy as it would have been the first time.

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Old 05-14-2020, 08:50 PM
Chief of the 60's Chief of the 60's is offline
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Quote:
Originally Posted by MUSLCAH View Post
Use a razor blade and a blow gun..to get that paint off. If you just want to booger it up...with out getting into it...just use a skim coat of body filler on the broken edges....prime and paint. I did a guys 2004 Chevy van...just the nose and Windsheild pillars...flaking here and there...just did the filler thing and painted....still holding up 3 years later...lol
Never gave that a thought. Wouldn't polyester putty be better than bondo?

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Old 05-14-2020, 09:14 PM
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I wonder what it would cost to just media blast the car then. I don’t want to take the chance now because it’s on quite a few panels...

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Old 05-15-2020, 10:49 AM
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I took a picture. Is this it or something different?
Am I good to sand, fill and feather this and paint over?
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Old 05-15-2020, 10:54 AM
Chief of the 60's Chief of the 60's is offline
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That paint is all old, checked, cracked and has a lot of underlying sins beneath the surface. Sorry to say that there is really no saving it.


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Old 05-15-2020, 10:57 AM
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I dont want to save it. I just want to know if I can sand it, prime and repaint over it for now. So I dont have those spots this summer.

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Old 05-15-2020, 11:00 AM
Chief of the 60's Chief of the 60's is offline
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I wouldn't

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Old 05-15-2020, 11:01 AM
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Quote:
Originally Posted by Chief of the 60's View Post
I wouldn't

Get it media blasted?
Or paint stripper?

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Old 05-15-2020, 11:26 AM
Chief of the 60's Chief of the 60's is offline
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Quote:
Originally Posted by Tomaso View Post
Get it media blasted?
Or paint stripper?
Never did media blast. Did paint stripper, it sucks! PITA and a huge mess. I like 40 grit on a DA and follow up with 80 grit. I would consider soda blasting if I had to strip one today.

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Old 05-15-2020, 11:52 AM
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Quote:
Originally Posted by Chief of the 60's View Post
Never did media blast. Did paint stripper, it sucks! PITA and a huge mess. I like 40 grit on a DA and follow up with 80 grit. I would consider soda blasting if I had to strip one today.

I was thinking about that method too. But someone mentioned it would gouge the metal? Is this true?
Or could I just stick with 80grit?

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Old 05-15-2020, 01:19 PM
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Dustless blasting, worth paying for it, if you don't want to put a tool together to do it.

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Old 05-15-2020, 02:02 PM
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Quote:
Originally Posted by Tomaso View Post
I was thinking about that method too. But someone mentioned it would gouge the metal? Is this true?
Or could I just stick with 80grit?
40 will leave swirls in the metal, heavy primer would take care of that but would involve a lot more sanding. 80 knocks the 40 down to where a regular primer coat can easily take care of.

Keep in mind, you are using a dual action (DA) sander not a circular one. Using 40 grit in a circular fashion would "grind" the metal. You don't want that.

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Old 05-15-2020, 02:03 PM
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Quote:
Originally Posted by Formulabruce View Post
Dustless blasting, worth paying for it, if you don't want to put a tool together to do it.
I believe the OP asked how much? Inquiring minds want to know.

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Old 05-15-2020, 03:10 PM
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Quote:
Originally Posted by Chief of the 60's View Post
40 will leave swirls in the metal, heavy primer would take care of that but would involve a lot more sanding. 80 knocks the 40 down to where a regular primer coat can easily take care of.

Keep in mind, you are using a dual action (DA) sander not a circular one. Using 40 grit in a circular fashion would "grind" the metal. You don't want that.
That's not too bad. If the filler primer will work than that sanding shouldn't be an issue.

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