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I painted my ‘77 with some cheap acrylic lacquer paint from one of those online touch up paint suppliers back in the summer of 2016. I’ve since moved to Texas where it is more humid and rainy, and I’ve noticed a bunch of little blisters that are maybe 1/16” in diameter popping up on the top surfaces of the car. I never noticed this until I started covering the car to keep rain from soaking my carpets (the car sits outside). I’m not sure if there’s any way to know for sure but I’m curious what you guys think the cause of these blisters could be (just moisture or other contamination?) and what I could do when I paint it again the right way in the future to keep this from happening.
It’s hard to see the blisters in this photo, I do have a better photo somewhere but can’t find it. They look like the ones in the photo above, but there are a lot more of them
The blister is coming up from under the paint
Meaning something in the substrate - (primer or body)
what happens when the car is in the sun.....?
Regardless the panel would need stripped down to bare glass and see if there is a problem there....
According to DUB, covering a car with a wet car cover and allowed to then sit in the sun can damage a car's finish. Fortunately, here in Southern California, 330 days of the year are sunny with no precipitation. If these defects appeared after covering the car, I believe that there is a definite cause/effect. The contaminated surface could also be contributing to the condition. You might try to leave the car uncovered and in the sun to see if there is a change in the appearance but the damage may already be done.
According to DUB, covering a car with a wet car cover and allowed to then sit in the sun can damage a car's finish. Fortunately, here in Southern California, 330 days of the year are sunny with no precipitation. If these defects appeared after covering the car, I believe that there is a definite cause/effect. The contaminated surface could also be contributing to the condition. You might try to leave the car uncovered and in the sun to see if there is a change in the appearance but the damage may already be done.
YEP...If the car was fine and then covered outside and I do not care with what type of fancy-dancy car cover. It will more than likely cause the car to be in a really bad environment that can effect the paint in time.
Like I have proven to customers who live where I work at. I told them to go out the day after the car got rained on and when the sun is out in the middle of the day.... go and pull the cover off and open the door and see what it is like. Those customers who actually did it basically AGREE with my comment on it being like a greenhouse.....which is not good for paint and many other things on the car.
The car needs to breathe and the car covers do not allow it to breathe that well. Put our hand behind your fancy-dancy car cover and blow on it and see how much air actually gets to your hand...and then you can make your own decision.
Car cover companies say that the car can 'breathe'...but that term is subjective if you think about it.
I’ve left it uncovered for a few months and it’s only gotten worse. I had read DUB’s warnings about that and was concerned about it but opted to keep water out of the interior and risk the paint. I guess it is what it is now, I’ll just keep it uncovered unless it rains and not worry about the paint unless this could cause damage to the fiberglass.
Does this happen because the paint isn’t thick enough, or can this happen regardless of the thickness of the paint? I don’t remember seeing blisters like that before I stripped it down, and I know the previous owner covered it at least some of the time, but the car had several paint jobs on it.
What can cause these blister can be several things.
1.) Moisture in the air line when it was painted. 2.) A contaminated surface that was not so dirty that it caused the paint to 'fisheye' ...but bad enough to cover crap that is now expanding when it gets hot. 3.) Solvents from the undercoat that was applied prior to the paint ( if any). These solvents were trapped due to insufficient flash time and now these solvents are try to to find a way out when the panel gets hot. Usually it is much worse than what you photo shows...but it still can be possible. 4.) The body has been subjected to moisture and now it is actually in the structure of the body material. When this happens...usually it occurs on horizontal surfaces. Because moisture rises and will collect up on the underside of horizontal surfaces or possibly the top area of some panels like your doors where there is a channel that can hold moisture
Thanks. That makes sense. I didn’t apply any sealer before paint, I just did primer, base, and clear, but I don’t really remember how well I followed the instructions for the paint. Not happy with the way it came out but I guess it was a good learning experience. I can’t cheap out and take shortcuts and get good results. Next time I’ll definitely be seeking advice from you so I can do a better job.
Thanks. That makes sense. I didn’t apply any sealer before paint, I just did primer, base, and clear, but I don’t really remember how well I followed the instructions for the paint. Not happy with the way it came out but I guess it was a good learning experience. I can’t cheap out and take shortcuts and get good results. Next time I’ll definitely be seeking advice from you so I can do a better job.
I will be here if you need me but understand that one of the things I will mention is that you spend some money on materials and practice on test panels or things that you do not care get messed up.
I know this seems crazy...but if a person jumps right in and starts to spray stuff...when they have never done it before (not knowing if you have painted many things in the past)...they may get a rude awakening when problems begin to show up on their 'pride and joy' they are painting.
I get it from local people who will not do what I suggest because they feel that they are doing it to save money...so why spend money on materials when it is on going on the project car. But...they are also the people who either bring the car by or have me go to their house and look at it and tell them what went wrong. Sometimes I just go . Little do they not understand or consider is that the time, effort and the ADDED materials that it will take to fix their mess-up...could have been avoided in most cases.
I do plan to practice on other things before painting next time. Last time I practiced on a couple things but didn’t really practice with the products I ended up using on the car. I’m probably gonna replace the bumpers and hood so I’ll have the old ones to practice on.
I do plan to practice on other things before painting next time. Last time I practiced on a couple things but didn’t really practice with the products I ended up using on the car. I’m probably gonna replace the bumpers and hood so I’ll have the old ones to practice on.
Very wise move to do that.
Many times people think that 'paint is paint'...but that isn't the truth. Different paint manufactures make their paint...and often times where that paint can act differently that others when applied....or have different properties to it that may or may not allow you to do things with it like other paints.
I am sure when you go into it again you will have great success as long as you do all that you can to make it as successful job.
Paint blisters
. Little do they not understand or consider is that the time, effort and the ADDED materials that it will take to fix their mess-up...could have been avoided in most cases. 
