fiberglass or paint problems?!?

[Mark Morrison]

I HAVE A MAJOR PROBLEM IF YOU KNOW ANYBODY I COULD CALL OR TALK TO THAT KNOWS ABOUT PAINTING/CORVETTES/PROBLEMS:

I got some bad news from the body shop today. My new paint job has to be stripped off again. This has now happened 4 times in the last 6 months!!!!

Here's the drill. They clean (dupont 3939 enamel cleaner). They strip (sandpaper -not chemical). They prime, paint, and clear coat (all Dupont products they have used for years).

After this process (about 4 - 6 weeks) some little "pimples" somehow "bubble-up" from underneath.

Last time they decided to go all the way through the gelcoat and use a two part epoxy primer (similar to what is used on boat hulls). Then they brought it up from there but same result, in the same time frame!

Everyone agrees there is some "stuff" (solvent, oils, or other contamination) "underneath" in the fiberglass that wants to come out. Now for a solution!?!?!

1) CUT OUT AND REPLACE THE ENTIRE REAR OF THE CAR (only place that bubbling has appeared). YUCKKKK - BAAAAAD CHOICE

2) REMOVE PAINT FROM REAR OF CAR, APPLY CLEANER, USE HEAT GUN, BLOW DRIER (OR OTHER) AND REPEAT A FEW TIMES TO "DRAW OUT" THE OILS/CONTAMINANTS.

3) OTHER CHOICES/OPTIONS?

I'M OPEN TO SUGGESTIONS!

AND I WOULD GLADLY EMAIL PICTURES, OR YOU COULD CALL ME COLLECT AT 808 960-2089 WITH ANY IDEAS, OR PEOPLE TO CONTACT, OR ???

THANKS AND ALOHA,

MARK MORRISON, #22477

[George Daina]

As you state, baaad stuff.................

suggestion that may or may not help.....strip to bare glass, let it sit outside and bake in the sunshine, (same as using a heat gun), wipe clean w/slow drying thinner. Let it bake for at least a month

[mark34178]

Re: fiberglass or paint problems?!?

I used to live in South Texas where the sun is very hot and had a similar problem on the deck lid of a 1969 T-Top. I stripped it down to the fiberglass by sanding (no stripper was used), used primer/surfacer, sealer, color and clear. At the time, 1982, all lacquar products were used as it was before urethane products became the norm. After a few weeks in the sun had the small pimples in the paint. The way I finally solved the problem was to sand the finish down again to the fiberglass and spray about 3 coats of Featherfill which is still available. It is very thick and uses a catalyst to set up. I sanded it smooth and went over with the same products I used to paint the car previously. Never had any problems again.

[Ed Jennings]

Re: fiberglass or paint problems?!?

I was going to make the same suggestion earlier, but decided I didn't know enough about new paint systems and had better keep my opinions to myself. The featherfill will also repair any areas where the gelcoat is thin and the glass fibers may show through the paint. It is a sprayable polyester material. Used it on a 58 years ago to take care of gelcoat damage.

[Dale Pearman]

Thanks For The Capital Letters

I'm very hard of hearing.

Dale.

[Dale Pearman]

Corvettes Weren't Buiult With Gelcoat *NM*

[George Skalkeas]

Re: fiberglass or paint problems?!?

Gentlemen: I am no expert on body work or painting but I do know that original Corvette fiberglass came with NO gelcoat. Accordingly, trying to solve the problem with the assumption that gelcoat plays a part may not be the best approach!

[James F.]

Re: fiberglass or paint problems?!?

Mark, Mark 34178 gives you some good advice. As primer on my recent paint job I used Morton's Eliminator, a non ISO catalized primer. It worked well for me. I decided to use it after a lot of research and comments from painters who did use it. I'm not connected with Mortons yada, yada. Also, consider the possibility of moisture in the air line. Regards,

[George Daina]

Featherfill has been......

replaced by Slick Sand. Same product but easier to sand, and yes it covers. Makes Gel coat obsolete.

[Ron De Vries]

Re: fiberglass or paint problems?!?

Mark,

Being in the pacific side of the great white north, I have a few customers of mine that have have similar problems. Moisture being the biggest. One way that I have seen done is to seal the back or inside of the panel so water cannot come through from the back side. If this is the case make sure your vette is very dried out before you repaint and seal it.(unless you like fresh paint every 4-6 weeks or so. It will save money and time not having to buy and apply wax).

One other thing that causes bubbles in the paint here is car covers. I have seen more than one vette totally destroyed, paint wise with a cover on it. I flat out refuse to sell them here for this reason. Moisture gets caught between the car and the cover(after a wash or a drive etc).. the sun hits it or the just heat from your engine and little pimples to silver dollar sized bubbles form in the paint with a really nice black oily liquid inside. A little off topic but it may save your paint next time if you do use one. A simple dust cover(cotton and see through) is all you should be using. So save your money, they are NOT worth it.

Good luck and hope my 2 cents helps. Ron DeVries

[Ed Jennings]

Maybe that's the wrong terminology

but there is a layer of resin on the top which has no glass strands in it. When this layer is not present, you can sand it smooth as you want, but the strands will show through. It's like trying to paint the end of a piece of celery. Just sucks the paint up. A guy named Bob Paris who had a restoration shop in Norfolk, Va. years back put me on to Featherfill. It saved the old 58. It had been sanded with a grinder among other things. It wasn't perfect when I finished, but I saved it from becoming a parts car. Car was originally a 250Hp auto fuelie. Auto and FI both long gone.

[Dale Pearman]

Featherfill Is A Great

product. But at St. Louis two primer colors only were used. The double press molded panels did contain a mold release agent on the surface of the fiberglass that was similar to a sealer but no separate sealer or gel coat was applied at the Corvette factory.

If you are repainting a Corvette today you should use a high tech sealer or the much more labor intensive PITA gel coat!

Dale.

[George Daina]

Use Gel Coat?

Absolutely not. When you see thousand spider web cracks all over the vettes body, that is the outer mold release cracking, when you spray gel coat on top pf the mold release, it will be just a matter of time before Gel Coat also cracks.

Featherfill/Slick Sand is the way to go, easier to apply and use, and results are fantastic. Reason Master Judge The Dale won't advocate using Slick Sand IS................he can't tell if Slick Sand is used on a car and with a gleem in his eye, deduct 1000 points for non factory sealer. He knows the product is used, but he can't prove it.

BTW, all those tiny spider cracks? Ya gotta eliminate them with "V" scribe and fill with, I like a product called Dura Glass, filler with fiberglass strands that works.

[Bill W.]

Re: As you state, baaad stuff.................

heat gun and sunshine are not the same . a heat gun does not have u.v. rays.

[Bill W.]

Re: fiberglass or paint problems?!?

Ron is correct i had that problem on my 62 i left a wet folded cover on the back of the car and it caused bubbles. and this was a 15 year old paint job at that time .the rest of you are trying to cover up the problem not fix it. the problem is there are solvents trapped in the fiberglass ,the sun will draw them out paint are no paint .DO NOT USE 3939 ON RAW FIBERGLASS it has a very slow evaparition rate. raw fiberglass should have nothing but soap ,[tide or dawn] no car wash soap it has wax in it.water,sandpaper if a solvent is needed use a high grade of lacquer thinner it will dry. after all sanding is done the bare glass needs to be in the bright ,hot sun a few days. if it is not you take the chance of the bubble man coming to see you.if you have replacement pnls. good luck many of them have release solvents traped inside.