fiberglass interior finish

[dpollitt]

I am buying a catamaran that has had its wall treatment taken out leaving bare fiberglass. Does anyone know the best and lightest way to put some of this back. Concerning the fiberglass that is there...is it possible to fair it in some way and then paint it back to a glossy smooth finish. Sort of like a home wall...put compound on, smooth it out, sand it down, repeat and then paint.....voila...lovely smooth surface. Is there any thing like that in a marine application?

david pollitt

[Hud3]

Hello, dpollit. Welcome to CF.

A simple and relatively inexpensive solution would be to cover the surfaces with a heavy duty vinyl wallpaper.

[Weyalan]

Yes. Fairing compound (a.k.a. filler). It is basically like plaster for boats. There is a wide variety available. Speak to your local fibreglass suppliers and they will recommend a product (or products) that will be appropriate for your application.

Basically, you will need (1) Resin, and (2) Fairing compound. The resin will be 2-part. Epoxy is probably best. The fairing compound is like a powder that you stir into your resin to make a thick paste (kinda like plaster). Typically the compound will be microsocpic balloons or fibres (or a combination of both).

Basically, you sand the fibreglass surface, then clean it (typically with acetone). Then you mix up your fairing compound; which, because it uses 2-part resin, will "go-off" (harden) fairly quickly, so only mix relatively small batches. You screed your filler

You apply the fairing compound over your fibreglass surface, typically with a plasterer's trowel. Get it as smooth and even as you can. Let it go-off (harden) completely, and then you can sand it (typically with an orbital or palm sander, but hand sanding also works) to a perfectly smooth surface. The thing is, though, that it is quite hard work to sand, so you really want to get as close to an even surface when you lay it on, otherwise you will spend days sanding it back to "fair".

After the fairing compound has gone off, you may need to re-fair it with more compound to fill low areas, rather than sanding the whole thing back to the lowest point.

Once you have the surface-filled and faired/sanded to your satisfaction, you can finish it off with an appropriate high build primer and top-coat.

[dpollitt]

Interesting...does that vinyl paper have something that goes on first or does it go directly on the bare fiberglass?

thanks
david

[David M]

I would go the fiberglass fairing and then painting route. Have you ever had to remove any sort of wall paper? Its not fun and over curved surfaces it may be impossible for it to look right.

This is my favorite epoxy fairing compound.
Interlux Watertite Epoxy Filler Fairing Compound - iboats.com

[knottybuoyz]

System Three QuickFair is another filler that's pretty good.

Boat Builder Central - products

Another option might be a lightweight liner such as Coroplast covered with a fabric of your choice.

Coroplast - The Leading Manufacturer of Corrugated Plastic

A little trim work and it's done. No messy sanding & painting. FWIW just an idea.

[hellosailor]

David, there are industrial/commercial wall coverings that are like softer thinner versions of Formica. I'd suggest filling and smoothing is going to be an intense waste of materials and time and money. Either "panel" the hull with some type of liner like that, or glue down a very thin dense foam layer (to get a smooth surface, or a denser thicker one to add insulation/padding) and then apply a liner layer on top of that. The factory finish was probably similar to one or the other.

[mikereed100]

Jeez Rick, that Coroplast idea is brilliant! I may give it a try myself.

Mike