""Bleed Thru""

[C3alex]

Some other members and myself were talking on another thread about oil and other contaminents bleeding through the fiberglass from the underside of the hood causing bubbles in the top paint. I thought it to be a very important subject and started this new thread.

Members Phill and Koop has had bleed-thru damage from engine oils and AC compressor oil. My compressor blew but I didn't experience any damage....yet !!

Has any other members experienced this type of damage to the top side of their hoods from oil migration through the glass?

Alex

 

[bmotojoe]

My understanding is in the late 1970’S GM started experimenting with synthetic lacquer base paints. I know that most complaints by customers were related to the finish of the paint and many cars were repainted by the dealer under warranty. I bought my 1977 in 1982 with 29,000+ miles on it so I know its history pretty good and the paint finish is the original. The under hood blanket is almost as clean and dry from any contaminates as the day it was installed. The hood on my car starting getting small blisters in the paint just back of where the air cleaner sits years ago. The rest of the car shows no signs of any of these defects so I am assuming it may be heat related rather then contaminate related.
Also it is my understanding that these hoods came from the 1976 hood mold so there were the cutout for the grill insert that needed to be fiber glassed in so maybe this also has something to do with it. JMO
Brian

 

[TWINRAY]

I painted both of my cars - the '69 about 1980 and the '67 in 1989. I primed the '67 in 1977 and it was in storage until 1989 when I put the top coat on. Paint was Dupont Lacquer with their epoxy sealer - no clear. In the late '90's, both cars (on just the D/S top fender) started to "pit" (for lack of a better word) like acne

with an oily residue coming from the pit. It is worse on the '67 and damage extends to the cowl area and I have started to scrape it off with a single edge blade - I don't want to use stripper cause of the chemicals. I've heard various causes like: solvent pop, bad preparation and even that it was caused by fumes/vapors from the master cylinder attacking the glass. The last seemed the most "reasonable" if just for the simple reason that there are NO problems anywhere else on the cars. I have a "problem" with the bad prep answer cause the cars were good for many years and except for this fender issue, still are. The rest of the paint on both cars (especially the '67) is relatively perfect. The '67 doesn't have A/C - the '69 does, but the compressor is not in the area where I am having a problem.

 

[6880 Mike]

All C3s were shot with acrylic lacquer with the exception of the Bowling Green cars. If there is a leak, AC compressor oil/R12 can be thrown on to the underside of the hood and can leach through the fiberglass to cause the blisters your cite.

The aftermarket folks carry a compressor guard for this problem.

I've never heard of regular engine oil leaching through fiberglass.