Painting fibreglass.

[firko]

I'm soon to paint a very used and abused fibreglass replica BSA tank and now that I've removed six different layers of paint I've found a few very fine spider web style cracks in the gelcoat. My worry is that these cracks may eventually show up through the paint so...is there any special preparation involved in nullifying the cracks or am I being an old worry wart and all will be OK? 

[bazza]

Had crazy cracks in a f/glass Maico tank (not the one im going to give you) Mate put a thin resin coating over it and was ok

[yamaico]

Hey Mark,
Sorry to put a damper on things but the crazing will definitely come through. Either what Mike says (resin coating) or use a good quality epoxy primer. Sanding first with 80 grit freecut will provide a good surface bond for the primer,
Pete.

[firko]

Thanks Mike and Pete.
The tanks not going to be a show item, it's just to replace my unobtainium Cheney tank when the bike's being raced. Having said that I still want the tank to look reasonably neat so I'm presuming a good quality two pack, perhaps with a bit of extra hardener might last a bit longer than a rattle can job before the crazes start to appear...or am I just being hopeful?

[yamaico]

If you use a rattle can they will probably come through as you're painting Try a high build primer and then whatever you like over the top - that will probably keep them at bay for a while.

[Noel]

Sand the gel coat back to the base fibreglass, where there is  crazing,  prime and paint
Noel

[Davey Crocket]

I'm no expert on it Mark, but go down to your local boat shop or google FGI fibreglass, the boaties do that shit all the time. Have you got me a pre65/60 mount for next years nats?

[Rossvickicampbell]

can agree with the good primer  -worked a treat on my side panels - and then all came up good.