Press 'n Seal Blisters

I've been using Glad Press 'n Seal as masking material for quite some time. But today I got a nasty surprise when I removed some from my Speedster. I had left it on the car for several days, so there was the usual light residue. I've seen this before but it's come off easily with polish. But this time there was more: I've got blisters on my clearcoat!

It's on both doors. There has been water on the car during the time it was PnS'ed; I'm not sure whether that's a factor in the blistering. I was able to sand down the blisters, but they went clear through the clear, and there was some light pitting in the color coat. So I'll have to spray the area again.

From now on, I won't leave Press 'n Seal on a car for more than a few hours. And I'll remove it right away if moisture gets under it.

Actually, I'd like to find something else to mask large areas while painting. I don't like to tape everything; it's a pain and can do damage because it's so sticky.

I never, ever leave masking on a car. I mask, I spray, I remove the masking, all in one session. This is because I know that it is more than likely I'll have some sort of compatibility issue between masking material and paint such as you have suffered. The Press 'n Seal is excellent for a masking medium for large areas, but don't leave it on there for any longer than necessary. Plan the painting tasks so that you mask, paint, and remove the masking in one session.

Oddly enough, Tom, I've been conducting an experiment with this stuff. I wrapped a body painted with Dupli-color lacquer and cleared with Rustoleum lacquer then let it sit for a few weeks just to see what would happen. It left the little adhesive marks but they are wiping right off (I disrobed the car after reading your post). There doesn't appear to be any damage to the paint job. No moisture, except for ambient humidity, was part of the equation so that might be the biggest problem.

Not exactly scientific, but I wanted to know what the worst case would be if the Press'n Seal were left on for an extended period. Of course, the safest course is to remove any and all masking materials as soon as feasible.

And I'm sorry to hear of any setbacks on your Speedster build. Still looking forward to the completed build.

I wrapped a body painted with Dupli-color lacquer and cleared with Rustoleum lacquer then let it sit for a few weeks just to see what would happen.

The car was cleared with U-POL (a synthetic lacquer like Tamiya TS-13). It had been dry for a couple of weeks before I masked over it, so it wasn't "uncured." Your results - and my good results in the past - suggest that the water catalyzed the Press 'n Seal adhesive and the clearcoat, causing the blisters.

U-POL is a professional product that ought to withstand almost anything. I doubt that it was the problem here. Who would imagine that the gentle adhesive on Press 'n Seal would cause such a reaction?

I'm taking Zoom Zoom's advice: Leave that stuff on the car as briefly as possible. And from now on, I'll take special pains to keep water from getting under it.

In the interest of "closure":

The pitting on the color coat was worse than I originally thought, so it needed quite a bit of sanding and a re-spray. The U-POL clear went on nicely, as it always does. So I seem to be out of the woods and almost back to Square One. If I don't have any more setbacks, the model should be done very soon.

It's been a long process; the Fujimi Speedster does not exactly snap together over a weekend. It looks promising; hopefully, it will have been worth it.

Thanks for the suggestions. Stay tuned.