Blisters in 3 month old paint job

G

gregstith

Hey guys, I've heard of this but never experienced until now. I did some paintwork on my father-in-law's cadillac 3 month's ago. On one of the quarter's there are about 20 blisters that have now appeared. They look just like drops of water.

When I painted the car I didn't take the panels down to metal, I just roughed up with DA, then some SPI primer, blocked, PPG DBU, 3 coats universal clear - 30 min. between coats.

He hasn't waxed it, so I wouldn't think there would be any trapped solvents. It was also not overly warm when I painted it. So I don't think it flashed too soon trapping any solvents.

Any ideas. Thanks.
 
Show some photos and I bet you'll get some answers, blisters usually mean there's problems coming from below the products that were applied.
 
Don't have any photos right now. Imagine roughly 20 drops of water on the panel.
 
Pictures..

You can come up with pictures.. Its 2011,, Have them sent to a phone or have someones phone send them to your eamil or whatever.. Like I said,, You can get pictures, you shouldnt expect people to "imagine" anything..

Bubbles can be imagined in many ways.. So just get some pics up and we can further help you!!

Have a nice day!!:cool:
 
I can imagine that they look like the ones that were on the hood of my half a truck where previous damage had been repaired. Some sort of acid had been used and not properly taken care of is my best guess.
 
SOF, that is exactly what happened with this car. Notice the blister in the center of the picture. It can up when I was buffing and then would go back down but not completely.
Turned out to be from using Metal Prep and I had to strip to bare metal and start over with epoxy. Lesson learned: bare metal always gets epoxy first.

P1010011.jpg
 
gregstith;9963 said:
Did you repair yours? If so how? Thanks for the reply.
Click to expand...
I sanded it down to metal, washed with solvent w&g remover, then washed again with waterborn w&g remover. Then a double coat of the worlds best epoxy.
 
Anything that can react and create a gas will make bubbles, like soda blasted metal sprayed with etch primer, for example. Trapped solvents can also create bubbles. Sometimes it's anyone's guess. But "Senile Old Fart" has the right cure, for sure.
 
pilgrimcustoms;10040 said:
Trapped solvent has done it to me before. Rushing between coats of any materials is a death warrant. Add hot sun and...
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Very unlikely that was the cause, so soon.
Being a Cadillac, for older the most common reason for a bubble would be painting over the factory lacquer.
Next most popular reason is painting over an acid.
Slight chance rust pin holes in metal and water coming from back side.
It would be one of those three things most likely, you can tell when you pop the bubble.
 
i have a whole car that is blistered like poison oak on skin from car store metal prep...didnt know any better... ive also gotten it from oil base w&g remover soaking into unsealed evercoat featherfill and painting too soon...
 
I've gotten bubbles from getting it to hot to soon from the heat lamp,
(cooked it really good)
and from putting it in the sun to soon, especially lacquers on wood.
I've done it all when it comes to the "wrong way" :eek:
 
Hey Barry, I was wondering about painting over lacquer. The driver side had been resprayed in bc/cc and the clear was all peeling that's why the repaint. I don't have any blisters on that side.

The passenger side was a single stage that was all starting to flake off in some spots it was very dry and brittle. I sanded down to the existing primer. Shot a couple coats of 2k, blocked and sprayed base. Would the lacquer primer under the 2k cause this?

Also, what do I need to look for when I pop the blister? Thank You!
 
Barryk;10057 said:
Very unlikely that was the cause, so soon.
Being a Cadillac, for older the most common reason for a bubble would be painting over the factory lacquer.
Next most popular reason is painting over an acid.
Slight chance rust pin holes in metal and water coming from back side.
It would be one of those three things most likely, you can tell when you pop the bubble.
Click to expand...

1: Being a Cadillac, for older the most common reason for a bubble would be painting over the factory lacquer.
2: Next most popular reason is painting over an acid.
3: Slight chance rust pin holes in metal and water coming from back side.

I understand what popping the bubble for #3 would show, but please tell what it would look like for #1 &
#2


Thanks
 
gregstith;10085 said:
Hey Barry, I was wondering about painting over lacquer. The driver side had been resprayed in bc/cc and the clear was all peeling that's why the repaint. I don't have any blisters on that side.

The passenger side was a single stage that was all starting to flake off in some spots it was very dry and brittle. I sanded down to the existing primer. Shot a couple coats of 2k, blocked and sprayed base. Would the lacquer primer under the 2k cause this?


Also, what do I need to look for when I pop the blister? Thank You!
Click to expand...

Yes and yes it will and does.
Here is what can happen, the lacquer primer may have over the years lost 50-75% of its solvents, now you further hurt the lacquer by sanding and getting air to it.
When you spray the 2K, loaded with hot urethane solvents, the plasticize-rs in the lacquer will try and rejuvenate themselves and they will, as the solvents melt the primer and then the primer soaks up all it can, some areas will have soaked enough to be like new and other areas may have only soaked up enough to get it like a 5-10 year old primer.

Now the heat causes the lacquer primer to expand at different rates and that is why it bubbles.

Cut top of a big bubble with a razor blade just shaving off the top, look and see where it stops and smell right away as the smell is good for about 10 seconds, shold smell like solvents, if not its water.
 
Barryk;10097 said:
Yes and yes it will and does.
Here is what can happen, the lacquer primer may have over the years lost 50-75% of its solvents, now you further hurt the lacquer by sanding and getting air to it.
When you spray the 2K, loaded with hot urethane solvents, the plasticize-rs in the lacquer will try and rejuvenate themselves and they will, as the solvents melt the primer and then the primer soaks up all it can, some areas will have soaked enough to be like new and other areas may have only soaked up enough to get it like a 5-10 year old primer.

Now the heat causes the lacquer primer to expand at different rates and that is why it bubbles.

Cut top of a big bubble with a razor blade just shaving off the top, look and see where it stops and smell right away as the smell is good for about 10 seconds, shold smell like solvents, if not its water.
Click to expand...

Now where else you gonna go to get an explanation like that? Thank you Barry for being you.
 
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