Paint air pockets

[1750GT]

Hi all, I have a 1970 Alfa 1750 GTV and have recently noticed some marks on the paint work that look like minnute airpockets no bigger than a couple of milimeters across. When I press on them they disappear and then re-appear. They are not broken and I suspect it's bad undercoating or moist undercoating because if it was rust it would be comming thru given the car was painted by previous owner some 12 years ago.

Has enyone else noticed the same sort of problem with their paint work? and can you give me some advise.

1750GT 

[Ray Pignataro]

Sounds like moisture blisters  more noticeable in humid weather. when the air gets hotter and drier you will not notice them as much.

[Gary Pearce]

Sounds nasty. You need a paint expert to have a close look at it. About 10-12 years ago there was a issue with a particular brand of paint that reacted badly to a (different) undercoat. If you come to Spettacolo there will be people more qualified than I to give you an opinion.

[Davidm1600]

yes i would definitely agree with the other comments, it definitely sounds like micro blistering due to moisture getting under the painted surface. From my experience there are a number of ways they can form including if during say the repainting of a car, the painter was slack in removing moisture from the paint lines, since moisture is formed by the condensation of air via the compressor.  There is a bleed valve to remove the moisture as it collects in the line but if not watched will get into the air/paint mixture in the spray gun. 

Also another way I have seen such bubbles form is due to sweating when car are left under car covers for too long.  This happened to me with my 1750 GTV.   The problem being that once you have such micro blisters in your paint there is the real risk that you will also get surface rusting and if that happens there is only one option stripping the affected areas to bare metal, derusting the metal and repainting.

I would definitely get it checked out by an expert spray painter, panel shop.  Good luck.  Dave

[1750GT]

Thanks for your responses guys. Does anyone know of a good paint expert that is helpful and does a quality job in Melbourne?