Fiberglass Questions...

[Nick09]

I am about to start building a kayak, (i know a little different from the projects i see mostly posted on here) but, anyone who knows about fiberglass can help. I need either a kevlar, carbon fiber, or fiberglass cloth in order to build it, and kevlar and carbon fiber are too expensive, but i cannot find 6 ounce fiberglass fabric that comes in colors. So my question is, how do i finish say a glossy black finish. Is it possible to paint the actual fiberglass so i can keep the woven look? Or does anyone know where i could get cheap kevlar or carbon fiber, or colored fiberglass?

Thanks

[PAR]

Several suppliers sell regular 'glass fabric, but with the carbon weave and in black. It' doesn't have the physical qualities of carbon, but it will easily tolerate a lot more UV. Most 'glass supply house can order it, some actually carry it.

Call Joel over at "Boat Builder Central" (tell him PAR sent you). They don't show it in their on line catalog, but I'm sure they can order it for you.

You can try a search for black fiberglass, maybe finding a local outfit.

Expect it to cost about 20% more then similar weave undied fabrics.

http://www.fiberglasssite.com/servlet/the-38/Black-Fiberglass-Cloth%2C-5/Detail

[Nick09]

Does the weave even show up in fiberglass? I do believe, (please correct me if i am wrong), that normal fiberglass goes clear after you epoxy it. If i get black fiberglass will you see the weave, or will it just be black?

[PAR]

Regular 'glass goes clear because it's glass (literally), just like what you put beer in. Colored glass (just like what you put beer in) doesn't go transparent. A fabric's transparency is dependent on how heavy the fabric is. Truly transparent is 4 ounce and under (per sq. yard) regular 'glass fabric, over 4 ounce and the weave begins to show. The 3 twill weave of common carbon fabrics is distinctive and quite visible, even if the fabric isn't actually carbon. The stuff listed above is an 8 or 9 ounce fabric, so it'll easy show. Of course you'll want some sort of UV protection over it resin (I'm assuming epoxy) and I'd recommend either a solvent or water based LPU.

[Nick09]

Thank you for the help PAR. I have one more question though because i think i have changed my mind about the black weave. I think i am going to do something like this. My question is, what do you think the white is on the bottom? is that just paint or is it fiberglass also?

http://www.stewartriver.com/images/northernlight.jpg

[Herman]

Paint or gelcoat.

As you probably want a lightweight boat, go for paint. (gelcoat needs a mould, which you probably do not have, and gelcoats easily adds 0,5 kg or more per m2)

About carbon look: Als consider basalt fiber. A bit brownish-black, but not unpleasant to look at, actually.

[PAR]

As Herman suggested, it's very likely paint. Gel coat is difficult for the backyard builder to apply well.

[Cobra1]

As Herman suggested, it's very likely paint. Gel coat is difficult for the backyard builder to apply well.

No it's not.:D :D

[robherc]

It's all in what you want really, you can get glass, or polyester, or whatever, dyed in almost any color you want, but you have to know what you're looking for before you can find it. :-)

Also, if weight is all that critical for you, you could get some white pigment to add to your epoxy to get the painted-white effect on the bottom...but you'd want to find an epoxy with good UV stability if you aren't going to overcoat it!

[PAR]

There isn't an epoxy that has a "good UV stabilization". All epoxy formulations, at least all the ones we'll use in laminates or barrier coats will require additional protection from UV. About 95% of the time, this will be paint.

Cobra1, you're mean dude . . . :p

[Herman]

There are epoxies that have "increased UV stability" which means they turn yellow later and slower...

But they do turn yellow...

Throw in some white pigment, and leave the boat outside. In about half a year, you are in for a good laugh, as parts of the boat are turned yellow now, and parts are still white. And this might be in "swipes" or "spots".

However, white pigmented epoxy laminate is a good base for a thin layer of white paint.