advice on paint issue needed

[Bill S.]

my 66 is in the shop to fix some blistering i had on the drivers side fender on the top. i also have the issue on the cowl top as well. the shop sanded it down but noticed after it sat over night the spots appear wet indicating that some thing is surfacing. any ideas of what we have and how to correct it?

[Paul S.]

Re: advice on paint issue needed

Sounds Like Maybe Brake Fluid Bleading Thru, Can You See Anything On The Inside Of The Fender?

[Terry M.]

Re: advice on paint issue needed

Wasn't there one of the brands of reproduction fiberglass panels that had issues with resin bleeding out of the panels?

[Chuck G.]

Re: advice on paint issue needed

Wasn't there one of the brands of reproduction fiberglass panels that had issues with resin bleeding out of the panels?

I think some folks had trouble with Corvette Image panels for a period of time, Terry.

Not sure if the problem has been rectified now.

In this issue, if it's not a replacement panel, there's some kind of contaminate soaked into the fiberglass. The master cylinder is REAL close.

Chuck

[Terry M.]

Re: advice on paint issue needed

I agree. Actually my first thought was the refrigerant oil from the air conditioning system, but I didn't voice that due to the location of the bleeding. I wasn't trying to suggest it isn't brake fluid -- I am just exploring the range of possibilities.

[Bill S.]

Re: advice on paint issue needed

i didn't know what was meant by "inside the fender" it has no A/c. it is an original fender. i know about brake fluid as that happened to my 70. being on the cowl in the center top between the hood and windshield makes me doubt brake fluid. my body shop suspects some type of stripper. reguardless, it is contamination of some sort, any ideas how to control it and go forward? or will we need to ID the contamination first? and if so how?

[Frank M.]

Re: advice on paint issue needed

my 66 is in the shop to fix some blistering i had on the drivers side fender on the top. i also have the issue on the cowl top as well. the shop sanded it down but noticed after it sat over night the spots appear wet indicating that some thing is surfacing. any ideas of what we have and how to correct it?

Bill,
I know this is an old post, but I have the same problem. I acquired my 66 roadster in September of 1998. At that time the car was pretty tired. The paint job looked like it was done with a vacuum cleaner. I had the blistering on the drivers side front fender, starting were the fender meets the door and extending toward the front 18-24 inches and on the upper firewall panel between the two vent panels. I started restoring it in January of 1999, leaving the repainting until 2013, when I had the car repainted. I specially told the painter that I wanted the problem fixed. The paint job looked great when I got it back, however, I had moved to Tucson, AZ at that time, and we have a lot of sun out here. Two month after I got the car back, it started to blister again. I took it back to the painter, who told me that he had under estimated the job, and basically if I wanted it fixed I would have to pay for it or sue him. I wasn't happy, but decided I could live with it. In 2016, I decided I really couldn't live with it and started looking on the discussion board for what caused this problem. This is when I found your post dated 5/13/09. I also saw a similar post from Bill Wilhelm on 5/15/09. I've been a member of the NCRS for about 23 years. I like to read the threads, but I probably have only posted two or three times. It seems I can only find the problems and recommendations, but never seem to find the resolutions. Now fast forward to December 10, 2022, when I was out driving my and was stopped at a red light. All of a sudden, Boom! I was rear ended and pushed into the car in front of me. To make a longer story shorter, in addition to the insurance proceeds for damaged parts, I decided to shell out part of my own money and buy a whole new frontend. I figured that would end my blistering. I am now at a reputable body and restoration shop and after pulling off the whole front end he has told me that I have that same blistering on the upper part of my firewall under the cowl area. He is concerned if that area is not treated, that new cowl area may become infected. He has suggested doing some of the things that have been mentioned as a response to your problem, but I would prefer to have actual experience solutions if available. I hope you can help me out and if someone else has solved the same issue, drop me a line. Sorry about the length of the narrative.

[Bob R.]

[Mark M.]

Re: advice on paint issue needed

I've seen this on a 66 and 69. Both cars have all their original panels. Both cars had an increase of blisters as the years gone by, on front and rear panels. Both cars had older complete repaint jobs but I don't know how they were stripped or prepped. The blisters on both cars if opened, seem to release an oily fluid. The 69 is still the same today and needs a complete paint job. The 66 was stripped and all panels were cleaned underneath and on top with degreaser and thinner. A heat lamp was also used and placing the car in the sun with wiping the oily material off many times with thinner until it seemed to stop over days and weeks. Sprayable polyester resin on all panels and the shaping begins. This takes much time and labor and there's no guarantees. Don't know if it was previous stripper or oil from tired engines with leaking pvc ??? Three years later the 66 looks great but who knows what time and the sun may bring out. The panels are porous and how densely manufactured may effect this but clean and seal as best as possible is all you can do.
Limit time in the sun should help, especially a dark car.

[Frank M.]

Re: advice on paint issue needed

Bob,
Thanks for the reply. When the car was purchased back in 1998, most of the blisters had been popped on the front fender and nothing was coming out. There were some unpropped blisters in the cowl area between the wipers, which I didn't pop. I knew I was going to have the car repainted someday so I left them alone. The heat in northwestern PA is nothing like Tucson, AZ so knowing what I know now I should popped them to see what might have come out. When I finally had the car stripped, the shop blasted the car with walnut shells( first mistake) and I never had the opportunity to see the car at the bare fiberglass stage( second mistake). I'm still finding walnut shell debris on the front seat floor mats eleven years later. I am working closely with my current repair shop, and I will be there before anything is applied to the stripped fiberglass.

In regard to your comment about removing the applied stripper from the fiberglass, I found a number of threads from February 16, 2001 that address that issue in great detail. I'll be sure to give that info to my shop. Thanks again.

Frank

[Frank M.]

Re: advice on paint issue needed

Mark,
Thanks for the info. Since the infected parts have been removed from the car and will not be repaired, I'll be able to see what's going on, both on top and on the bottom, and prepped based on your recommendations. This will be done just for my satisfaction and to possibly help the next person with this problem.

After reviewing a lot of threads, there seems to be a lot of 1966 vets that have this same problem. I've got a very basic understanding of the evolution of fiberglass panels on the C-1 and C-2 corvettes. The question arises that is it possible that the original problem was created at the factory from a faulty mixture of the resin and hardening agent or not allowing for the mixture to set up long enough. Perhaps someone with knowledge of this process could chime in. Just a thought with no back up to support it. Thanks again.

Frank