Production Clear over unpainted fiberglass

I

inspectorbob

Can I use Production Clear on unpainted fiberglass? I am restoring a motorhome and wanted to try to find a product that would bond to the fiberglass without using a primer or base. I just want to clearcoat the white fiberglass. If so, what prep would be needed?

I thought about reducing it and wiping on several thin coats by hand. Would that work?

Thanks

Bob
 
Bondoskimmer;21853 said:
Wipe? Why not spray?

My original plan was to spray. I removed everything I could and repainted the parts with silver grey metallic (the original color) in my garage (compartment doors, trim, mirrors, etc), and they came out great. The balance of the rig is white gelcoat, with a few painted graphics. This is 35' long, so I tried to paint some of the graphics outdoors. The problem is, we live near the coast, and the wind is always blowing. I ended up really fighting the spray to get it on even the best I could, and ended up with a lot of runs and uneven coating. Unfortunately, all the runs occured along irregular shaped trim pieces, and it was a mess trying to remove them. Now, I will need to be doing some touchup. I can deal with that on the painted graphic areas, but I didn't want to be fighting it on the majority of the surface, which is unpainted gelcoat. I called Barry (thanks for your help, Barry!) and he suggested I paint outside at dawn to avoid the wind. The problem for me is that at dawn along the coast, the dew is like a heavy mist, and everything is still wet.

I had read about companies that make an acrylic polymer coating that you apply once every year or two by wiping it on in 4-5 really thin coats for the initial application, then 1 coat every year or two to renew it. Then I read about company called Vivilon (www.vivilon.com/recrepics.html) that make wipe-on urethane clearcoats that are supposed to last 5-7 years , so I thought maybe SPI's product would work if I reduced it enough, and used multiple thin coats. How about it, Barry? This is a big market! there are a lot of unpainted, ugly faded motorhomes and campers out there that need your magic!!

Thanks for your input.
 
to be honest, I would hesitate to use anything but epoxy (including epoxy resin or things like vinyl ester fillers) or gelcoat directly over raw fiberglass. The solvents soaks into the resin and glass and can cause problems over time. Gelcoat is 100 percent solids (all of what you spray becomes the solid coating). ALWAYS shoot epoxy primer, or gelcoat over raw glass... it's worth the extra step if you don't want it to show through or bubble down the road. imho...
 
wca_tim;21903 said:
to be honest, I would hesitate to use anything but epoxy (including epoxy resin or things like vinyl ester fillers) or gelcoat directly over raw fiberglass. The solvents soaks into the resin and glass and can cause problems over time. Gelcoat is 100 percent solids (all of what you spray becomes the solid coating). ALWAYS shoot epoxy primer, or gelcoat over raw glass... it's worth the extra step if you don't want it to show through or bubble down the road. imho...

A question now for a future project since this ones up today...
Are you saying Epoxy 'or' Gelcoat? or that epoxy will work if you need it to?
If I was redoing a fiberglass body and stripped it (razors) down to the bare glass and made my repairs it would be 50/50 more or less whether I used either one to seal with?
 
wca_tim;21903 said:
to be honest, I would hesitate to use anything but epoxy (including epoxy resin or things like vinyl ester fillers) or gelcoat directly over raw fiberglass. The solvents soaks into the resin and glass and can cause problems over time. Gelcoat is 100 percent solids (all of what you spray becomes the solid coating). ALWAYS shoot epoxy primer, or gelcoat over raw glass... it's worth the extra step if you don't want it to show through or bubble down the road. imho...

"I just want to clearcoat the white fiberglass."

I believe he is wanting to put clear over the existing faded gelcoat.

Best thing I can suggest is do a small test panel and see how it goes. Let it cure for a week or two then put some good tape on it and pull to check the adhesion.
 
Either one would work as long as you seal the bare glass area with something other than urethane. Using urethane over old gelcoat works just fine. I've done a couple of metalflake boats with severely faded gelcoat this way. They come out looking great IF you do the prep right and are careful about what you're doing. From boating background...

don't use solvent based systems over raw glass areas

do use epoxy (either resin or paint) or gelcoat over raw glass areas

don't use polyester resin (ie gelocat or standard glass resin) over epoxy

that's my current best understanding and experience...
 
If your going to all the work to properly prepare the surface for clear coat, why not base it and have somethin when your done???
 
if you like the color it is, but the surface of the gelcoat is oxidized and porous, it works well to wetsand the oxidized gell off with something like 320 or 400, being careful not to break through (gel is a LOT thicker than paint), degrease it THOROUGHLY prior to sanding, clean with a strong aqueous based cleaner, let it dry and shoot two wet coats of clear over it. It'll look great and hold up well. imho

ps. this works especially well on flake / clear boats where the gel has oxidized over time. if you break into the color you can also use an airbrush with some tinted intercoat to touch up the fades, etc...
 
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