Paint Blistering

[Donald W.]

Any comments on what causes paint to bubble or blister on corvette body paint finishes. Any way to repair other than strip and repaint.

Thanks for your comments,
Don

[Ralph Harlan]

Re: Paint Blistering

Is this a new finish? Old paint? Original paint? Enamel/polyureathane/lacquer?

[`Michael Southard]

Re: Paint Blistering

On my lacquer, I understand it's because there are solvent gases trapped under the paint. A result of not thoroughly washing prior to prime and paint.

[Donald W.]

Re: Paint Blistering

Paint is Black Enamel (PPG Deltron 2000 base coat clearcoat) applied a little over 1 year ago.

[Mike M.]

Re: Paint Blistering

i'd guess there was contaminants in the air supply to the paint gun( water and/or oils). looks like its time to re-strip the old girl and repaint. mike

[kelly theaker]

Re: Paint Blistering

paint blistering is a definate adhesion problem, either substrate - filler or primer . small pin type blistering is a trapped solvent problem usually caused by not enough flash time between the coats and solvents were trapped and the sun is now trying to leach them out. strip it or admire from a distance.

[Rich G.]

Re: Paint Blistering

Don

I bought a 66 3 years ago that had recently been painted by the previous owner. It exibited a few blisters the size of a quarter or bigger on the top of both front fenders. Figuring I had little to lose and after talking to a friend who paints airplanes I tried this:

I stuck a pin in the center of the bubble and worked around the edges with my fingers at the same time cooling things with an ice cube. I read someplace that dry ice is used to take small dings out of soft aluminum, so I figured cooling it would help. I did this in warm weather. It worked. I can find one of the spots if I look real hard, but the rest are gone.

This worked real good on big spots. I have one small one that I can't get to go down, but it's so small, you wouldn't notice it.

The paint on my car is DuPont "Chromabase"...not sure what that is, but it is not BC/CC.

Good luck.

Rich Giannotti

[Bob R.]

Re: Paint Blistering

I had a blistering problem on my 63. I just had the car repainted this summer. When the car was stripped it was obvious what caused the problem. There were multiple layers of old paint. The newer paint did not adhere to the old.

[Ross Flora]

Re: Paint Blistering

I had blister problems on my '72. I had the car refinished. The guys doing the work told me the there was too much paint on the car in some spots and small cracks in the fiberglass that allowed moisture and such to wick through an unstick the heavy paint

[Stephen W.]

Re: Paint Blistering

Blistering is cause by two things and both happen during application of the finish coats or the primers. Large blisters are usually moisture related and these can get there a couple ways. In the thinner used to reduce the primers. In the thinner itself ( cheap thinners were popular for primers ). For the home DIY situation it can be the use of a compressor thats to small. The little guy works so hard it is overheating and pumping water through the air.
The other type of blister is solvent "pop" Tiny droplets of trapped solvent that expand to form a tiny blister. Flash times, proper mixtures and correct temps for spraying correct this. Ever see a guy in a shop spray primer on then wave the gun over the panel blowing air on it to speed the dry? He just created a huge future problem.
I would say that the use of epoxy primers, sealers, and complete systems ( all PPG or all Dupont ect) helps to eliminate these problems. Cure times not being rushed no "force drying" and proper maintenance of spray equipment will eliminate the other half of the problems.
Lastly you can spray over an existing finish if its a daily grocery getter but never do it on a Corvette... unless you don't care that it will not last and just want to stick someone else with your time bomb. Let me be clear on this point. I'm talking about doing a complete refinish over an existing paint finish not spot repair to fix a scratch on an otherwise good paint job.