paint question

[hrzracr23]

Hello all,

Today I started the prep work for the new paint job. I have painted a few tailgates, a bumper or two, ... a geo metro when I was younger lol. Anyway never painted fiberglass.

My paint was faded and anywhere they put a screw there were awful spider cracks so I thought I should sand these out instead of just painting over. So that?s what I did anywhere there were spider cracks I sanded them out down to the fiberglass. Job well done, so I thought until my friend who claims to know a thing or two about a thing or two when it comes to fiberglass informed that this was a fatal mistake. I should have, according to him cleaned the existing paint with solvent and then scuff up the clear coat and paint that.

Is this true? Is my paint job going to come out poorly? My next question is I read somewhere on here about a topside paint you apply with a roller that supposedly looks as good or better than spray on? Is this accurate if so what is this paint and where do I purchase?

Thanks,
Folks

 

[reelfishin]

Re: paint question

The only thing that would concern me is if you sanded through the gelcoat.
If it were mine, I'd probably sand to scuff the surface, fill the cracks with a sandable filler primer. Fiberglass also should have a self etching primer just like aluminum.

 

[drewpster]

Re: paint question

If you are going to use a marine paint system all of them have some form of high build primer designed to fill crazing in the gelcoat. (spider cracks) I agree that you should not sand through the gelcoat unless it is necessary to make a repair. You can fill the crazing with the primer so aggressive sanding may not be needed.

 

[ondarvr]

Re: paint question

If the cracks were just in the gel coat then you did the correct thing by sanding them out, if you didn't they would be back almost as soon as the boat was back it the water, if they go deeper then more work is needed.

Use a high build primer, or a filler to cover the areas that are down to the glass because there will be thousands of tiny pin holes and imperfections in that surface that will cause problems when you spray over them if you don't.

 

[drewpster]

Re: paint question

So, crazing should be sanded out?

 

[drewpster]

Re: paint question

Sorry about double post. You should sand out crazing prior to paint? Will the primer and paint not fill it?

 

[ondarvr]

Re: paint question

Yes, if at all possible, filler and paint don't have any strength, so when the area is flexed or stressed the cracks normally come back if not sanded out. If the gel coat is too thick, then it's prone to cracking, so you can sand it down to the glass and re-gel coat or paint. If there are other reasons for the cracking (damage or bad laminate), then those issues need to be addressed or it will crack again.