Hello I am getting ready to start body work on my fiberglass roadster. What is the best primer to use to seal up fiberglass? Thanks
If its a new body,you might want to go over the whole thing with a wax remover before any priming... Factories use a mold release to help from the body sticking to the mold..
When I did mine I washed the entire body inside and out with simple green, by hand. Then let it dry in the sun for a few weeks while I sorted out other items. After that, epoxy primer and blocked the car to find where it needed work. I was lucky it was nice enough to only need a few coats of high build primer and another round of block sanding. The seams I took care of before the first primer went on and that was all it really needed. Sent from my iPad using The H.A.M.B. mobile app
I always wash with soap and water then block sand block sand with 80 grit, making sure all of the shine is gone off the gelcoat .Then epoxy primer.
The best luck with either new or repaired fiberglass for me has always been spray gel coat! The primer becomes less of a factor from then on. I also have never had shrinkage problems.
Duratec makes a polyester based primer. Assuming your body was made with a polyresin. It was made to use on and under gel coat.
I use k38 PPG product and is a DTM. Have used it on glass many times. Do a scuff with 400 grit to get the shine off and provide some tooth. I think a wax/grease remover is standard on any surface prior to paint. This is a high solids material and blocks out beautifully with some soapy water and a long block and 400 then 600. Post photos of the project as it advances.
I used 40 on the seams, once they got close 80 grit on them. For the overall blocking/scuffing I used 120 on a long board, but 80 that has a little wear works well too or If you use cheaper papers, use the 80. For the high build I used 220 the first round checking for high and low spots with a guide coat...and 400 the second application and once it looked good to me. Keep in mind that If you let high build dry more than 48 hours it's gets harder to sand. Sent from my iPad using The H.A.M.B. mobile app
For prepping it. Scrub the whole thing with Dawn dishwashing liquid in hot water. After it's dry.... Wash the whole thing down with wax & grease remover, using the 2 rag method. Google 2 rag method. Sand the gellcoat with 180gt on a DA. Wash the whole thing again with wax & grease remover again with 2 rag method. This prep is to get rid of All wax and grease and to not have a fisheye problem.
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