What would make this happen.

5

540goat

Buffing out my car when I noticed in one area that the paint started to bubble. When it cooled it went away. Right there I knew there was a problem. I sliced the bubble with a razor and the paint peeled off right down to the primer(2k). I had sanded the primer with 220 and then put the epoxy on it then after the epoxy dried I hit that with 600 then the base. Then clear. Everything on this car was done textbook. What would cause this to happen.
 
you can create way too much heat with a buffer. in the days of lacquer it would turn to a soft rubber and never gloss again. i still buff at 1000 - 1500 rpm. takes longer but i dont like a lot of speed . check the temp of the panel regular so you can get off a panel when it heats up.
 
I spoke to James and he said it might be from the plastic letting gas off. I guess the heat from the buffer may have caused that.
 
Just an observation/question here......you say in this thread you used a 2k primer. Over on the chevelle forum you say you used Durabuild. Durabuild is NOT a 2k primer...it is a 1k acrylic primer.

So did you use a 2k primer or 1k primer?
 
I was thinking it was trapped solvents causing a local delamination when the heat was applied. Once adhesion is lost, there is no way to get it back. Having a 1K layer in there somewhere would make a problem like this more likely, but it can happen with 2K as well, especially in cold weather.
 
crashtech;15072 said:
I was thinking it was trapped solvents causing a local delamination when the heat was applied. Once adhesion is lost, there is no way to get it back. Having a 1K layer in there somewhere would make a problem like this more likely, but it can happen with 2K as well, especially in cold weather.
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After I sprayed the second session of clear on my car this summer, I took it outside a couple days later. I noticed a few small bubbles on the roof when the sun got it hot. Eventually they stopped showing up. I would guess it was trapped solvents, but how could that be? The primer sat in the sun for probably a week before I started paint. I always sun my primer between applications, as well. The first 3 coats of clear got a couple days of sun after blocking with 400. As far as I know, I did everything how I was supposed to, according to what I have learned on here. It really isn't a big deal and the problem is undetectable now, but I would like to learn from the experience.
 
540goat;15055 said:
. . . I sliced the bubble with a razor and the paint peeled off right down to the primer(2k). . .
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I assume the primer stayed on the car but the base did not adhere to the primer is this correct?
 
"Everything on this car was done textbook. What would cause this to happen."

540, this is in no way meant to be a slam, but the fact that something like this happened, just in this one spot and not all over, suggests that something you did or didn't do likely caused the problem. One of the biggest frustrations a painter will face is trying to figure out what went wrong. Can you tell us what specific steps you did from baremetal to paint? (any metal conditioners, wipe down with laquer thinner, bare hands on metal after eating wings or cheese fries :)
 
strum456;15076 said:
After I sprayed the second session of clear on my car this summer, I took it outside a couple days later. I noticed a few small bubbles on the roof when the sun got it hot. Eventually they stopped showing up. I would guess it was trapped solvents, but how could that be? The primer sat in the sun for probably a week before I started paint. I always sun my primer between applications, as well. The first 3 coats of clear got a couple days of sun after blocking with 400. As far as I know, I did everything how I was supposed to, according to what I have learned on here. It really isn't a big deal and the problem is undetectable now, but I would like to learn from the experience.
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It's so hard to say. That's the thing about taking refinishing to a higher level, there are SO many variables it's impossible to ever say with certainty. Just get as many things right on the money as you can, and from there on it's on a wing and a prayer.

I've had the problem you describe, but I thought it might be over filler that had some buried pinholes. I think they try to "breathe" with large changes in temperature. But it doesn't sound like your problem. Maybe in your case it was something a small as a slight sprinkle of moisture from the compressor, moisture which contains a kind of oil that won't necessarily fisheye, but could cause tiny spots to lose adhesion. Or maybe I am full of it, lol.
 
like barry says , you can do everything right but the minute you pick up that gun all kinds of crap can happen for no apparent reason. but my guess is you got it hot.
 
Thanks for the input, Jon. One thing I was thinking is the roof is the only part of the car that was completely horrizontal when I sprayed it (I hung everything I could). Is it possible that I sprayed the clear heavier on the roof, trapping the solvents? It was hot when I sprayed, and I let the clear flash for atleast 30 minutes, probably 45 to an hour. But then again, why wouldn't I have solvent pop?
 
RodMan;15080 said:
"Everything on this car was done textbook. What would cause this to happen."

540, this is in no way meant to be a slam, but the fact that something like this happened, just in this one spot and not all over, suggests that something you did or didn't do likely caused the problem. One of the biggest frustrations a painter will face is trying to figure out what went wrong. Can you tell us what specific steps you did from baremetal to paint? (any metal conditioners, wipe down with laquer thinner, bare hands on metal after eating wings or cheese fries :)
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After I sanded the metal I wiped it down with wax and grease remover, then repaired a small dent in the area. Primed the are then topped it off with epoxy, base and then clear. The only thing I didn't do that most do is I didn't put epoxy between the metal and filler. I am old school. I think either the filler wasn't mixed right or the batch was bad, I don't know. But the heat from the buffer got it going. The rest of the car is buffed and fine. I also I let the primer sit in the sun for a few days. Nothing was rushed on the car, I have been doing the body work on this for 3 years maybe longer. The only spot that was rushed was the one that bubbled. It was done the day before I painted the car.

Thanks for your help guys, now off to repair the spot. I have it feathered into the other side and I am just waiting for some epoxy that James was nice enough to send me for free. You have a customer for life.
 
If you'd stop using that 1K primer, you'd eliminate a big potential problem. If you are still using it , you can't really say you are doing it by the book, not the SPI book anyway.
 
Doesn't take much heat to cause a bubble. Just hand my 85 year old grandfather a wool buffer and your guaranteed a few spots like your talking about. Trizact, foam, and never stop moving the buffer have been my cure. Next buffer will be a flex that is variable like Shine mentions. It would be nice to slow it down, I seem to use my dynabrade 3" buffer more and more as it builds zero heat.
 
I've burnt clear but never bubbled it..... stopped using 1K primer years ago
 
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