Paint bubble
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 3,438
Likes: 41
From: Raleigh NC
St. Jude Donor '13-'14
Paint bubble
I moved the corvette out of the garage today for a thorough garage cleaning. It was a nice 86°F with hardly a cloud in the sky. This is what awaited me after about 7 hours in the sun. 
It is about half way down the drivers side on the fender. At this point, I want to mitigate the problem and prevent it from getting bigger. The car was repainted in 2006, but has lived in a climate-controlled garage until I purchased it about a year ago. I don't know if it has ever sat in the sun for that length of time.
Suggestions?
It is about half way down the drivers side on the fender. At this point, I want to mitigate the problem and prevent it from getting bigger. The car was repainted in 2006, but has lived in a climate-controlled garage until I purchased it about a year ago. I don't know if it has ever sat in the sun for that length of time.
Suggestions?
Melting Slicks
Joined: Jun 2009
Posts: 2,709
Likes: 3
From: Savannah GA
Have a seat. This is likely only the first of more bubbles to come as the car gets exposed to the elements. There are several reasons it might be bubbling; all of them require diagnosis and complete pant removal to cure permanently.
You may be extremely fortunate and have only this one area fight back against whatever contamination is below the paint in which case my advice would be to live with it for now... let us know if more areas fail as the car gets used some. Good luck.
You may be extremely fortunate and have only this one area fight back against whatever contamination is below the paint in which case my advice would be to live with it for now... let us know if more areas fail as the car gets used some. Good luck.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
Funny thing about fiberglass things sneak in from below sometimes. I have seen oil from the A/C units do this to hoods and oil from a tar like under coatings do this to the top of the surrounds right above the tires. Heat from the sun can draw it up.
Racer
Joined: Jun 2009
Posts: 409
Likes: 3
From: St. James, NC
Similar problem with mine...getting worse. My problem started around the taillights. The paint is getting to the point of lettting go. I have a big piece ready to flake off. Expensive to fix. I believe heat is a big contributor. My problem was caused by the garage door being up and sun shining on the back end of the car and heating up the fiberglass. The problem probably happens more with dark color vettes.
I feel your pain.
I feel your pain.
Pro
Joined: Apr 2012
Posts: 543
Likes: 10
From: B.F.E....Bowling Green Kentucky
My black 79 has several of these spots, and I've heard before thats its because of something getting on the fiberglass (bare, I guess??)
LeMans, I wouldn't worry too much, yours is still one of the sexiest I've seen,
Love that color!
LeMans, I wouldn't worry too much, yours is still one of the sexiest I've seen,
Love that color!
Safety Car
Joined: Jun 2004
Posts: 4,652
Likes: 80
From: Lakeland Florida
I have a similar problem on my 72. One area is at the top of the T Bar roof, and the other is on the right rear fender area. I am so tempted to pop it, or stick a needle in it, but then I thought it would only cause it to get worse. So I am living with it for now.
Nothing quite as large as the quarter size you are showing, but they are there nonetheless, and I dont know what to do about it other than live with it for now.
kdf
Nothing quite as large as the quarter size you are showing, but they are there nonetheless, and I dont know what to do about it other than live with it for now.
kdf
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
The fiberglass is 'out-gassing' because of some volatile comtaminant left on the surface or from some repair compound used below the paint; or it could be from some petroleum-based substance that bled through the fiberglass from below (like the A/C refrigerant/oil suggested above). I have them on my hood just above the front A/C compressor seal--obviously some failure of that system with the prior owner who had it repainted some years ago.
I think we all hope this instance is isolated.
I think we all hope this instance is isolated.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Melting Slicks
Joined: Jun 2009
Posts: 2,709
Likes: 3
From: Savannah GA
Make a photographic record of known trouble areas and look carefully for a cause after paint removal. Remember that fiberglass is both porous and permeable... things like A/C oil, undercoating, tire shine sling-off and silicone brake fluid drips can seep through the glass from below.
Also as you strip, pop the bubbles and lift the paint to see if you can smell trapped solvents in the area, or if there is liquid in the bubble which you might ID. If a painter applies too much film build without waiting for adequate dry time, those trapped solvents can "pop" the paint off if the car gets warm enough to evaporate them.
Fixing solvent pop is straightforward... remove everything and repaint using correct technique.
Cleaning contaminated panels is complex and time consuming... and the technique is somewhat dependent on the contaminant. Plain old Dawn dish soap and water applied both sides repeatedly is a pretty good way to start...just be certain you rinse well and allow adequate dry time before sealer.
Also as you strip, pop the bubbles and lift the paint to see if you can smell trapped solvents in the area, or if there is liquid in the bubble which you might ID. If a painter applies too much film build without waiting for adequate dry time, those trapped solvents can "pop" the paint off if the car gets warm enough to evaporate them.
Fixing solvent pop is straightforward... remove everything and repaint using correct technique.
Cleaning contaminated panels is complex and time consuming... and the technique is somewhat dependent on the contaminant. Plain old Dawn dish soap and water applied both sides repeatedly is a pretty good way to start...just be certain you rinse well and allow adequate dry time before sealer.
Melting Slicks
Joined: Aug 2008
Posts: 2,200
Likes: 3
From: Lehigh county Pennsylvania
***** them with a needle. Find out what's in them...just air or maybe some kind of fluid. Then slice with a new single edge razor blade. Flatten down with a squeegee. Doing this while it's warm out is best. The longer you wait, the more stretched the topcoat will get. Good luck.
Melting Slicks
Joined: Aug 2005
Posts: 2,683
Likes: 34
From: Working on the car NY
"leaching" on top of the drivers side fender started about 8 years ago. Looked like a bad case of acne. Read that it is fairly common with the way the vapors travel underneath the hood - then consider the wicking effect of a car thats been heat cycled for over 40 years.
Melting Slicks
Joined: Aug 2005
Posts: 2,683
Likes: 34
From: Working on the car NY
***** them with a needle. Find out what's in them...just air or maybe some kind of fluid. Then slice with a new single edge razor blade. Flatten down with a squeegee. Doing this while it's warm out is best. The longer you wait, the more stretched the topcoat will get. Good luck.
I'd just leave it - otherwise you'll end up stripping the whole thing and doing a repaint - and maybe have the same thing happen again. Just my .02 fwiw.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
For anyone doing a repaint, I would think that the underside of the hood should be painted with some kind of sealer or epoxy paint which would prevent engine compartment contamination from making contact with the hood fiberglass.
Melting Slicks
Joined: Aug 2005
Posts: 2,683
Likes: 34
From: Working on the car NY
I've read (FWIW) that the way to do it, is to take the finish down to the bare glass (and I wouldn't use chemical stripper), repeat wiping it down with acetone until contaminates leach less (it will take repeated wiping and you'll never get it to completly stop), gelcoat etc. to a completed paint job. I was told (again, FWIW) NOT to paint the underside (whether hood or fender top) so that the contaminates can now go (after the gelcoat) the other way out. They need to be able to get out someway. This is the procedure I'm using on my '67 but I won't be able to give results till next year. I thought I had my leaching stopped coming out from the top of the front fender but the $hit still comes out after a hot ride. But I still keep wiping down with acetone and maybe when I get around to finishing it, it'll stop - I keep hoping.
Last edited by TWINRAY; Aug 13, 2012 at 12:22 PM.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
I used SPI epoxy 
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 3,438
Likes: 41
From: Raleigh NC
St. Jude Donor '13-'14
Thanks for the replies. These paint bubbles are obviously frustrating for many. At this point I have no plans to repaint the entire car due to this blemish.
This is what I'm looking for. Since I believe the heat brought this about, its probably something volatile that has been released under the paint. Is pricking this a good idea? I can see it becoming a wrinkly mess quickly. I agree with the process, but I think I could make it look ALOT worse than a bubble.
My fear is that since it was only 86°F and sunny, a good 95°F and sunny will only make this bubble bigger.
***** them with a needle. Find out what's in them...just air or maybe some kind of fluid. Then slice with a new single edge razor blade. Flatten down with a squeegee. Doing this while it's warm out is best. The longer you wait, the more stretched the topcoat will get. Good luck.
My fear is that since it was only 86°F and sunny, a good 95°F and sunny will only make this bubble bigger.
Racer
Joined: Feb 2012
Posts: 319
Likes: 0
From: Daytona Beach Florida
Most likely gassing out.. The hot sun doesn't help.. Sometimes it corrects itself.. What I have done with other cars is put a tiny slit in it with a razor... Let it release in the sun for a few hrs.. Pref a few days.. Then seal it with a drop of clear... Fiberglass loves to gas out in the heat..had one the size is a basketball develop while baking the car...after it cooled it never returned..
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
You will find when it goes back in the shade it will shrink some. I also have had these on other cars. I would give it 6 months and leaving it in the sun every now and again. If no more bubbles arise I would not take any chances to just sand and repaint that section, Cut it out completely and reglass that section cause whatever is in that section will leach out forever even with heat lamps.
Last edited by gingerbreadman1977; Aug 14, 2012 at 02:57 AM.
Racer
Joined: Oct 2001
Posts: 474
Likes: 64
From: Portage La Prairie Manitoba
Had a similar looking problem with my 81 hood at the front.After 2 refinishing jobs on the hood we discovered water was trapped in the hood.Drilled drain holes at the lowest point of hood on the underside problem solved.