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Fiberglass filler primer etc.

PostPosted: Wed Sep 24, 2014 8:35 pm
by rizzz
As I'm nearing the end of my cowling fiberglass work I think (or maybe I should say I hope), I'm starting to think about eventually priming painting the fiberglass parts not necessarily something I'll do now but eventually.
During all this cowling work I've obviously been adding/removing fiberglass, drilled lots of holes, using fiberglass reinforced filler here and there etc.
I've also been using a gel coat repair filler to re-coat some of the areas where the gel coat was damaged and to coat the added fiberglass areas, this makes it all look nice and white and smooth again, although I’m not sure this is really necessary.

So what's next?
I assume something like:
Sanding, filling, priming, sanding, filling, priming, some more… and more…

I’m not entirely sure what the techniques are here, the sequence and so on.
Also would like some advice on materials, fillers primers etc. used.

Thanks.

Re: Fiberglass filler primer etc.

PostPosted: Sun Sep 28, 2014 8:55 pm
by rizzz
Anyone?

Re: Fiberglass filler primer etc.

PostPosted: Sun Sep 28, 2014 9:11 pm
by ScottM-Sonex1629
Michael,

It depends on how much you've burnt through the gel coat. I'm starting to paint my tail surfaces and you can see the process I'm using.

I also previously finished and painted an entire fiberglass kit car (Factory Five Racing, Mk3.1 Cobra replica) and you can look through my photobucket account for my finishing if that helps.

http://photobucket.com/albums/nn218/STL-Scott/FFR%206583-Build-Frame

I would use a polyester surfacing primer first, something like slick sand, which is a high solids, high build sandable primer surfacer. You can sand this just like the gel coat. You then want to hit any low spots with two part light weight body filler, then seal it all down with a good 2K epoxy primer. Next is a light wet sanding of the epoxy if if you have any orange peal in this coat, prior to paint. You can either use single stage 2k paint, or base coat, clear coat. If you want to go cheap rattle cans work but I'm not a fan of their durability.

Let me know if you have more questions.

Re: Fiberglass filler primer etc.

PostPosted: Sun Sep 28, 2014 9:21 pm
by rizzz
Thanks Scott,

Till now all I've done is filling in the scratches etc. using a gel coat repair filler:
http://www.supercheapauto.com.au/online ... 8601#Cross
I've also used this to fill the flush rivets which were countersunk slightly deeper than the top of the gel coat so I can hide them nicely.
So from here on the next step would be a polyester surfacing primer or can I go straight to the 2part epoxy primer given I'm filling in the gel coat with the repair kit?

Re: Fiberglass filler primer etc.

PostPosted: Sun Sep 28, 2014 10:03 pm
by ScottM-Sonex1629
If your happy that the overall shape of the cowling is good, you can profanely skip the surfacer primer. I forgot to mention when I did my cobra fiberglass body it was many stages of apply the body filler, then sanding to get the shape correct, filling holes, low spots, etc. after I had this done the surfacer primer was next which allowed me to long board sand to get everything nice and straight. Cars are different then a Cowling. You can probably skip to the epoxy primer, or just a urethane primer if you want. The epoxy primer is good in case you need to seal down body filler, so it doesn't bleed through your top coat.

Does that make sense?

Re: Fiberglass filler primer etc.

PostPosted: Sun Sep 28, 2014 11:04 pm
by rizzz
Great,
That certainly makes sense.

Thanks Scott.