ok what on earth would cause a bubble in the paint? my brother and I painted my car and we did notice near the head light doors fiberglass that were exposed to the elements. We were gonna fix this weekend, how do we go about doing this? He said he knows how, but he won't tell me I'll believe him when and if it worked. I say worked, cause I don't want to have to do this again.

is the fiberglass giving off some chemical release causing the paint to bubble? I look forward to the responses

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3800 SC/IC Formula Bluuuuuuuuuue!

[This message has been edited by LoW_KeY (edited 06-15-2006).]

Fiberglass shouldn't bubble. Most bubbling I've seen involved the filler used to bond two pieces together (Bondo). The filler only should be a skim coat, not too thick. It absorbs moisture and swells. The only fix is sanding the bubbles out and repainting.

Painting on a unclean surface might cause adhesion problems.

For SMC and fiberlglass cars, I wonder if the use of a sealer might be better AFTER body filler.

On a regular car, you seal the metal to prevent rust, then you do your bondo, fiberglass..... whatever.

But, if you do your bodyfiller work first, then seal it.... might work better...

How big of an area bubbled?

How long ago did you paint? You might want to wait a couple weeks before painting if there is body filler on there?

What KIND of paint? Base coat/clear coat , single stage, rattlecan?

Did you prime it first?

Was this just a spot repair, or is the whole panel fresh??

Did you wipe it down with Wax/grease remover, prior to painting? (Thats important)


Let us know....

areas not that big probably the size of my thumb, we primed/filled a couple of a weeks before the painting.

used PPG paint, 2 base and 2 clear (forgot the name of the clear it was a european clear coat) we used grease remover and then tack clothes. We baked it afterwards if that matters? but the decklid is fine so I'm not sure if that'd be the case.

the area that bubbled was just the spot that needed filled in so maybe it was something he caused? I know he talked about heating up the area and letting the chemicals release then doing it over

quote Originally posted by LoW_KeY: areas not that big probably the size of my thumb, we primed/filled a couple of a weeks before the painting. used PPG paint, 2 base and 2 clear (forgot the name of the clear it was a european clear coat) we used grease remover and then tack clothes. We baked it afterwards if that matters? but the decklid is fine so I'm not sure if that'd be the case. the area that bubbled was just the spot that needed filled in so maybe it was something he caused? I know he talked about heating up the area and letting the chemicals release then doing it over

Did you guys wet sand the primer?
Reason I ask is cause if you go any finer than 600 on the wetsand, that might also cause the paint to not stick so well.

The only other thing I can think of , is if the paint was improperly mixed.??? I know thats not what you would want to hear.

I am still thinking contaminants....
Edit:

Also... What kind of primer?

[This message has been edited by intlcutlass (edited 06-15-2006).]

no idea on the primer.. he used all the same stuff the body shop uses. Sanded the primer down and what not.. I'll have to double check over the work before we paint. Maybe something he goofed on and got contaminants on

quote Originally posted by LoW_KeY: no idea on the primer.. he used all the same stuff the body shop uses. Sanded the primer down and what not.. I'll have to double check over the work before we paint. Maybe something he goofed on and got contaminants on

Sorry man......Usually , paint is the one thing you can't just fix. If it gets screwed up , (usually), it has to be sanded down , and shot again.... Thankfully...you CAN do just 1 panel though....

quote Originally posted by LoW_KeY: we primed/filled a couple of a weeks before the painting.

im betting your filler/primer absorbed some moisture. that will cause a bubble.

I agree that there is most likely moisture in there. That's one of the reasons that I never wet sand before painting as there is a possibility of moisture being absorbed by the primer before painting, especially in a higher humidity area. I dry sand with nothing finer than 320 for the urethane paints so the new base has a decent surface to grab onto. 600 is too fine in my experience for urethane, but I used to use 600 for lacquer. Lacquer isn't worth it anymore. I also try not to let body work sit for too long as the longer it sits, the more prone it is to pick up contaminants.

Primer/sealer never hurts, and often it helps protect against old paint problems, but even the primer/sealer will absorb a small amount of moisture when wet sanded. The sealer should always be used after your bodywork as the primer is necessary for the paint to bond to. New paint will not stick to unprepared Bondo ( or similer ) and needs either that primer or a primer/surfacer.

Moisture is something that can trash a good paint job if not dealt with properly, and sometimes you just cannot get away from it. Good moisture traps are very necessary and will help to keep water from entering your airstream. One spit of water in the middle of the hood realy sucks. But, it sounds like your moisture problem, if that's what it is, is caused by moisture in the body work itself. If you had exposed fiberglass and wet sanded it after doing the filler work, you probably had the moisture trapped by the primer long enough to hold it in place until the paint was applied......and the clear coat is waterproof on the inside as well as the outside and the moisture had to go somewhere.......and the paint bubbled. When you pop the bubble, you'll probably find water.

Drop us a pic when you can....

Mark

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quote Originally posted by intlcutlass: Sorry man......Usually , paint is the one thing you can't just fix. If it gets screwed up , (usually), it has to be sanded down , and shot again.... Thankfully...you CAN do just 1 panel though....

OK -- off the wall fix but I have seen this work. For a small paint delamination I once used MicroSet to rebond the bubble. You have to have real patience and be very detail oriented or you may cause more damage (which would mean a panel repaint anyway, so might as well try this). I had a bubble on a car I painted to resell, about the size of a nickel. I pierced the bubble carefully with an xacto knife, not a big slice just a little prick. Relieved the water by gently pressing, working the bubble. When it seemed mostly gone I used an insulin syringe to inject MicroSet into the bubble. I made a second tiny xacto prick and worked the set through the void. I set up a vacuum pump, plastic and clay to pump out the air and apply pressure to the void overnight. The next morning the void was readhered and only a little clean up and polishing was needed.

MicroSet is a model airplane decal setting solution available from squadron mail order:

www.squadron.com

Model stuff often works great on cars (Tamiya XF20 gray is great for Fiero interior touch up).

Can't guarantee this will work for you, but might be worth trying. Easier than a panel repaint. Don't know about the long term durability, had the car for 2 months and was still OK when sold. If it fails you're no worse off, start sanding and repainting. Good luck!

Cheers

[This message has been edited by tutnkmn (edited 06-15-2006).]

I`m going with moisture too, did some work on my sons rear bumper, when I sprayed it with primer--that even bubbled up. Didn`t have anything to loose , so popped it with a pin & it was trapped mositure...

quote Originally posted by Firefox: I agree that there is most likely moisture in there. That's one of the reasons that I never wet sand before painting as there is a possibility of moisture being absorbed by the primer before painting, especially in a higher humidity area. I dry sand with nothing finer than 320 for the urethane paints so the new base has a decent surface to grab onto. 600 is too fine in my experience for urethane, but I used to use 600 for lacquer. Lacquer isn't worth it anymore. I also try not to let body work sit for too long as the longer it sits, the more prone it is to pick up contaminants. Primer/sealer never hurts, and often it helps protect against old paint problems, but even the primer/sealer will absorb a small amount of moisture when wet sanded. The sealer should always be used after your bodywork as the primer is necessary for the paint to bond to. New paint will not stick to unprepared Bondo ( or similer ) and needs either that primer or a primer/surfacer. Moisture is something that can trash a good paint job if not dealt with properly, and sometimes you just cannot get away from it. Good moisture traps are very necessary and will help to keep water from entering your airstream. One spit of water in the middle of the hood realy sucks. But, it sounds like your moisture problem, if that's what it is, is caused by moisture in the body work itself. If you had exposed fiberglass and wet sanded it after doing the filler work, you probably had the moisture trapped by the primer long enough to hold it in place until the paint was applied......and the clear coat is waterproof on the inside as well as the outside and the moisture had to go somewhere.......and the paint bubbled. When you pop the bubble, you'll probably find water. Drop us a pic when you can.... Mark

I was thinkn the sealer would be better as the last primer on these cars.....Normally though, it should be a High build primer, like Evercoat brands.... That way when you blocksand. you can get the panel nice and straight, and you will still have primer there...

I didn't know the sealers can absorb moisture..?? Do you mean the epoxy sealers???

Also good call on the final sanding before the BC.... I was thinking 400, not 600, (my bad).

A+ sir....

I see a lot of it on vettes and Fieros. Usually around the headlite doors on hood, and on Fieros around the edge of the sunroof glass. Its caused from the fibers in the glass becomeing exposed from overly aggressive sanding or accident and moisture getting the inside of the panel and becoming trapped. comes back after you primer it and paint over it, even if you put filler on it, it works its way back thru and causes it to bubble up over and over again. About the only cure is to grind it down into the glass fibers, drill some vent holes on the back of the panel and let it dry out for a week or more. Then you reglass, and fill the defect, sand and prime, paint and hope. I had one particular C4 that had 6" areas beside both headlites and came back 3 times. I finally gave up and we replaced the hood panel. I figured it had had antifreeze get inside the fibers in an accident and would never completely dry out. You need to peel it off in the area to tell if its bubbling from the body out, or from the primer or sealer to be sure of the problem. If its the paint bubbling off the primer (and its still intact), then moisture or oil got on the primer before it was painted.

Oh and Forgot, If STRIPPER was ever used on it and got into raw glass fibers, throw the panel away because you will never stop it. This is why I will never touch a plastic car thats been chemical stripped ever.

[This message has been edited by rogergarrison (edited 06-16-2006).]

My roof is bubbling too!! Right around the sunroof the paint has flaked and the fiber is exposed and a little past that the paint is bubbline slightly. Any suggestions?

quote Originally posted by intlcutlass: I didn't know the sealers can absorb moisture..?? Do you mean the epoxy sealers???

Any primer can hold moisture, even the epoxy sealers. When it comes to primers, they shouldn't be exposed to the elements. The sealer primers won't allow moisture to pass through as the sealer part of them prevents it, but they still can hold a little surface moisture. It's just one of those things we sometimes take for granted, and yes, I've had primer exposed to weather before and just sanded it off when it was time to get back to bodywork, so I have violated the ' rule ' myself. But, it's one of those things that can come back to bite you without warning.

Mark