Fiberglass questions
Hello everyone! In my search for a new van, I am thinking of getting one with a high fiberglass top. Or having a top (used or new) put onto a van. I'm reading up on restoring fiberglass and hav...
Forum Discussion
The gel coat on my Van's fiberglass roof was in pretty bad shape after 12 years of florida Sun.
I first painted it white with Interlux marine yacht enamel, 15 years ago, and later on Again with Rustoleum's topside yacht enamel( cheaper).
If one used any shine type product in an attempt to miraculously and magically fill the voids in the gel coat, Any paint applied at a later date will not adhere properly, unless the roof is scrubbed adequately with a solvent like acetone and a fine bristle brush and a rag to remove the contaminants from the 'magical' products
Spraying on a new gelcoat is pretty much fantasy, unless one has big bucks to throw at the problem.
Polyester resins handle higher temperatures and UV light much better than epoxy resins. Epoxy has much higher bond strength to substrates and is lighter and stronger, but totally overkill for a vans fiberglass roof. Vinylester resin has cured properties closer to epoxy and a mid range price, but is likely Not used in such applications.
Sanding a gel coat will not give one a fiberglass itch, unless they actually get through the gel coat and into the fiberglass, which is incredibly obvious when it occurs.
If one intends to paint a cracked gel coat, sand it to 120 grit and use a leaf blower to get all the dust out of the cracks. Compressed unfiltered air might blow oil/contaminants onto the surface which will cause the paint to be repelled. Paint it in the shade in multiple thin coats according to manufacturer directions. DO NOT apply thickly in direct sunlight or add another coat prematurely. With a roller and followed with a foam brush, a nice finish can be achieved, but it will never be as good as a paint applied with professional sprayer.
I use Star Brite marine polish every 12 months to keep it repelling water and dirt. The bead lasts for about 8 months. This last time i went 18 months and it took a lot more effort to get it clean and shiny.
Do not fear the cracked gel coat if the rest of the Van meets your expectations. Only if you can see actual fibers from the fiberglass poking through the cracks in the gel coat would you need to take a pass.
But do look closely to see if people have been walking around on the roof. Some have foam sandwiched in between the fiberglass, and a well placed foot can crack the fiberglass, allowing water into the open cell porous foam, seriously compromising its strength.
One can check at night for depressions/ cracks with a flashlight held low to the surface, but might need to apply some pressure to see if it is indeed compromised enough to warrant a pass.
I first painted it white with Interlux marine yacht enamel, 15 years ago, and later on Again with Rustoleum's topside yacht enamel( cheaper).
If one used any shine type product in an attempt to miraculously and magically fill the voids in the gel coat, Any paint applied at a later date will not adhere properly, unless the roof is scrubbed adequately with a solvent like acetone and a fine bristle brush and a rag to remove the contaminants from the 'magical' products
Spraying on a new gelcoat is pretty much fantasy, unless one has big bucks to throw at the problem.
Polyester resins handle higher temperatures and UV light much better than epoxy resins. Epoxy has much higher bond strength to substrates and is lighter and stronger, but totally overkill for a vans fiberglass roof. Vinylester resin has cured properties closer to epoxy and a mid range price, but is likely Not used in such applications.
Sanding a gel coat will not give one a fiberglass itch, unless they actually get through the gel coat and into the fiberglass, which is incredibly obvious when it occurs.
If one intends to paint a cracked gel coat, sand it to 120 grit and use a leaf blower to get all the dust out of the cracks. Compressed unfiltered air might blow oil/contaminants onto the surface which will cause the paint to be repelled. Paint it in the shade in multiple thin coats according to manufacturer directions. DO NOT apply thickly in direct sunlight or add another coat prematurely. With a roller and followed with a foam brush, a nice finish can be achieved, but it will never be as good as a paint applied with professional sprayer.
I use Star Brite marine polish every 12 months to keep it repelling water and dirt. The bead lasts for about 8 months. This last time i went 18 months and it took a lot more effort to get it clean and shiny.
Do not fear the cracked gel coat if the rest of the Van meets your expectations. Only if you can see actual fibers from the fiberglass poking through the cracks in the gel coat would you need to take a pass.
But do look closely to see if people have been walking around on the roof. Some have foam sandwiched in between the fiberglass, and a well placed foot can crack the fiberglass, allowing water into the open cell porous foam, seriously compromising its strength.
One can check at night for depressions/ cracks with a flashlight held low to the surface, but might need to apply some pressure to see if it is indeed compromised enough to warrant a pass.
