1973 corvette what’s the best way to strip paint off without hurting gel coat
Q. I have a 1973 corvette what’s the best way to strip paint off without hurting gel coat any help will be helpful.
A. First you have to realize that other than early Vettes they were not gel coated. Yours should not have gel coat unless it has been stripped in the past and gel coated prior to repainting. What is often thought to be gel coat is actually resin. When a part is actually gel coated a mold release agent is applied to the inside of a negative mold then gel coat (chemically different than glass resin) is sprayed into the inside of the mold and finally the fiberglass is sprayed into the mold and bonds to the gel coat. When the part is separated from the mold the gel coat is now on the outside of the glass part and forms a smooth outer coating which is often colored.
Originally posted on National Corvette Owner’s Association newsletter http://www.nationalcorvetteowners.com/
But starting in 1968, Corvette body parts were manufactured using a press mold process where the fiberglass material and resin are shaped in a two piece die-like tool. Press mold made much smoother parts and did it more quickly. Then in 1973 conventional fiberglass was replaced with sheet-molded composite, or SMC. SMC uses fiberglass, resin and a catalyst formed in a press mold but under high heat and pressure.
In all cases some of the resin oozes out of the surface of the glass material and forms a thin layer on the outside of the glass. This layer of resin is what is under the paint and almost universally mistaken for or improperly called gel coat. Although gel coat is similar in composition to fiberglass resin it is not chemically the same. But that really doesn’t matter because it’s like Kleenex, a trade name universally used to describe tissue.
Anyway there are various ways of removing paint from a Corvette without damaging the fiberglass resin under the paint. It can be done with chemical stripper designed for use with fiberglass, it can be done with a razor bade or similar tool to scrape the paint off or it can be done with media blasting.
The big issue is not what method you use but how well it’s done. I wouldn’t pretend to have enough space here to suggest how to do it properly and I definitely would not suggest that you try it yourself. I base my last statement on the fact that you asked the question which automatically means you aren’t qualified. Other than using a razor blade which if held upright (roughly 90 degrees to the surface of the paint) will strip the paint nicely. It does take time but not that much more than other methods and it’s less apt to damage the fiberglass or preexisting body repairs. There are lot so tings on cars that can be learned by reading a text or watching a video but this typically is not one of them. Doing this job right comes from years of practice.
Professional stripping should be done by someone highly experienced in stripping Vettes and no, stripping is not stripping a Vette is vastly different than cars with metal bodies. A warning, anyone who says it’s just stripping is someone to avoid like the plague. Also keep in mind that both chemical and media blasting will expose and usually obliterate any old body work under the paint. Finally both chemical and media stripping requires the use of specific fiberglass-safe products.
In the case of chemical stripping the product not only has to be fiberglass-safe but then has to be used absolutely as the instructions say or the car will be damaged. Most good chemical people use a kitchen timer cell phone timer app to keep the process to the minute because close doesn’t count. When required they also use hundreds if not thousands of gallons of water to neutralize the chemical reaction. Cutting corners will yield a paint job that might look okay for a few months but sooner or later the mistakes will come through your great looking paint. Blisters, bubbles, discolored spots and peeling areas are all common.
In the case of media blasting make sure the tech completely understands the different hardness of various materials. In media blasting the media should be about the same hardness as the fiberglass but different operators and different equipment may alter that. If the media is too hard it will eat away the outer layers of resin leaving exposed glass. Once glass has been exposed the costs start to skyrocket and the unqualified tech blames something about the car, previous work done on the car or some other fictitious story so you pay him for his mistakes rather than him eating his mistakes.