I have read lots of reports about solvent pops in the paint after using chemcal paint removers. Are the pops caused by the paint stripperor or the laquer thinner that a lot of people use after washing off the paint stripper? If you sand off the top layer of paint and wash the primer off with laquer thinner, will you still run the risk of potential solvent pops? Thanks for your help.
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Re: solvents and fiberglass
I am no expert, but i can share what happened to my car. I purchased my 62 mostly naked of paint. I was told it was paint stripped in the 70's and was stored in a barn over the years. When I fist purchased the car I washed it with water and let it dry in the sun. ( I purchased the car in September of 04)
Needless to say it went into the body shop to get some body repairs done and a full repaint.
The car was sealed with "Slick Sand" The car was put in a spray booth several times to cure the sealer, to cure the paint, Anyways I get my car back from the painter January 10th 2005 and put it in my garage to sit, Had it in a heated garage 55 degrees and the paint looked perfect,3rd week of April 2005 and its a real warm strong sunny day and I decide to clean the garages. I roll the 62 out on the drive way into the sun, 6 hrs later I am done cleaning the garages and as soon as I roll the 62 back into garage I see giant blisters 3" in diameter in 4 different spots. I thought it was just a paint blister but it actually went all the way down to the glass. The paint manufacturer came to my home to see what happened and his determination was.
Paint was stuck to the primer rock solid
primmer was stuck to the top surface of the glass rock solid
Before they sealed the car (and it was cooked in the spray booth)there must have been solvents still in the body glass or the solvents from the sealer wicked into a fissure of the glass and just sat there dormant, until the day it when into the sun and the solvents exspanded, and the could not go thru the sealer or the paint and just ruptured the glass.
So my words of wisdom that I will live by in the future is dont seal or paint a car in the winter, It needs the sun to allow the solvents to evaporate out of the glass.We thought cooking it in a spray booth was enough but it really needs the that mean radiant power of the sun to pull it out.
Again I am no expert on car painting this is just an account of what happened to me personally. -
Re: solvents and fiberglass
Years back, whenever I stripped a Vette with chemical stripper I would Neutralize the residue that could not be washed off the car by bathing the car with Vinegar mixed in water at a ratio of 10/1. Worked well. My feeling at the time was that dorment chemical traces deep in the glass caused a gas to form when sunlight reached it. Having no place to go it blistered. Al W.Comment
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Re: solvents and fiberglass
Laquer thinner and acetone are not good solvents to use for wash down of a surface prior to painting. First the flash rate is too fast which means that you have to flood the surface with liquid to have a chance of removing the contaminants before the liquid evaporates. Particularly with fiberglass these are a poor choice because that flood of liquid can penetrate pores as well as wick along fibers. Once the fluid is in the laminate it is slow to evaporate out. You can force the evaporation with heat - but be careful not to exceed 115 degrees (F) surface temps, and don't rush it. Otherwise when the new coating is applied and you leave your toy in the sun the outgassing of the solvent WILL cause problems.
Another reason not to use laquer thinner or acetone is that neither is a very good solvent for contaminants. Years ago I thought I would wash the grease out of a set of front wheel bearings with acetone. Guess what - didn't work. Did not dissolve the grease. So how will it remove the contaminates? One of my friends would not listen to me in preparing a Soling sailboat for IMRON. He washed the prepared surface with clean rags and laquer thinner. As he sprayed the IMRON the residue of the thinner transmitted through the IMRON leaving a "wet look" he really did not want.
There are too many commercially available products specifically for the final wash of the surface to be painted. This is another case of working with the manufacturer of whatever coating you choose to use. Ask their representative what is the recommended product to use as a wash solvent as well as the proceedure they recommend for use on raw fiberglass.
Chemical strippers can be a problem of their own. Many are based on methylene chloride, which is a carcinogen. Methylene chloride is another solvent that can wick along fibers in fiberglass, and worse, it can soften the resins in the glass if it is left long enough (wicks into the laminate and cannot be easily removed? Oops!) It can also soften various fillers, such as BONDO. If either occurs while you are stripping the paint, there will be a problem with the repaint. It only takes a few spots to really ruin your day.Comment
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Re: solvents and fiberglass
car car was in for paint last year. My painter specializes in older vettes for the last 30 years so has a bit of experience.
He will only strip a car using chemical strippers as the other alternatives run too much risk of damage to the body.
the way he works it is this:
He only does one panel at a time. apply the stripper, let it sit and do it's work than scrap off the bubbled up paint. if needed reapply more stripper and do it again. once a panel is stripped down to the 'glass he first wipes it down with lacquer thinner, than washes it wiht warm soapy water, than rinses it with clear water, than another wipe with lacquer thinner. Only after thoughtly cleaning the panel will he move on to the next panel.
Once the entire car is done, he repaeats the cleaning process all over again with a wipe down of lacquer thinner, than warm soapy water, clear water, and a last wipe down of lacquer thinner.
After that he lets the car SIT UNTOUCHED for at least two weeks. He feels that letting it sit to have any possible remaining chemical solvent residue "vent" out of the fiberglass.
Only after letting it vent for at least two weeks will he than begin any body repairs needed before painting.
If the weather is warm and the sun is out letting the car sit outside during the day under the sun is even better, if it's winter and the weather is cold, keep it inside in the heated building. The warmer the temps while venting the better.
he said in 30 years of doing it this way he has never had a car come back with solvent popping. His method must work or he is a VERY lucky painter.Comment
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Re: solvents and fiberglass
Many thanks to all who took the time to reponded to my query, I really appreciate the advice offered by all. I am going to have my 63 SWC repainted and I do not want to run the risk of any future solvent pops, thus my concern.Comment
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