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TexTuba
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Post by TexTuba »

Anybody ever try to make a carbon fiber mouthpiece just for kicks? How practical is it?









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Chuck(G)
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Post by Chuck(G) »

jacobg wrote:It seems that carbon fiber is cheap enough to be used by fledgling bike frame companies, who can't have operating expenses that much bigger than your average boutique tuba company.
If I'm not mistaken, the reason for using carbon fiber in a resin composite is that carbon offers greater strength than, say, glass fiber.

If that's the case, why bother? I wasn't aware that a tuba needed to be awfully strong. Seems to me that a fiberglass tuba would be less expensive to build.

...and it seems that there's already someone doing just this:

http://www.musik-glassl.de/home.html
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Kevin Hendrick
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Post by Kevin Hendrick »

Chuck(G) wrote:If I'm not mistaken, the reason for using carbon fiber in a resin composite is that carbon offers greater strength than, say, glass fiber.

If that's the case, why bother? I wasn't aware that a tuba needed to be awfully strong. Seems to me that a fiberglass tuba would be less expensive to build.

...and it seems that there's already someone doing just this:

http://www.musik-glassl.de/home.html
There are two possibilities when "material A" is stronger than "material B", but no heavier: (1) use the same amount (which makes the component stronger, but no heavier), or (2) use less (which can make the component either lighter-but-the-same-strength or a-little-lighter-and-a-little-stronger). Lighter-but-the-same-strength might be worth paying more for ... :)
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Rick Denney
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Post by Rick Denney »

Chuck(G) wrote:If I'm not mistaken, the reason for using carbon fiber in a resin composite is that carbon offers greater strength than, say, glass fiber.
Does FRP use the same binder plastic as carbon composites? I don't think so. It seems like fiberglass uses a polyester resin, while carbon composites are usually constructed with epoxy resins. You can tell us the difference, which I think matters here. I frankly don't know, but I figure you will, heh, heh.

I do know that you can dribble a carbon-composite tuba bell like a basketball and it won't break, while fiberglass sousaphones are not known to be indestructible. I have handled one that was made by the same fellow that made one for CD.

Rick "thinking that CF has more tensile strength, but the compressive strength is provided by the binder" Denney
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Chuck(G)
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Post by Chuck(G) »

Rick Denney wrote:Does FRP use the same binder plastic as carbon composites? I don't think so. It seems like fiberglass uses a polyester resin, while carbon composites are usually constructed with epoxy resins. You can tell us the difference, which I think matters here. I frankly don't know, but I figure you will, heh, heh.
First off, polyester is cheap compared to epoxy.

You can do carbon or fiberglass with either binder. Epoxy's more expensive and takes longer to reach full cure. But when I'm wrapping shovel handles, I'll use epoxy+fiberglass--if a handle bends under stress, no harm. Do the same thing with polyester and it'll start cracking.

Epoxy's also used when laminating up a wooden canoe--it's not nearly as brittle, so scraping a rock will not produce nearly the mess on an epoxy-bonded canoe that it will on one that's been made iwth polyester resin will.

Similarly, if I wanted a bulletproof flight case, I'd specify a layup of carbon, glass or kevlar in epoxy. That's not what Walt Johnson uses, however, and I imagine the reason is that polyester + glass is "good enough" and it's lighter.

http://winshipmodels.tripod.com/resins_ ... erials.htm

OTOH, it's simple enough to repair a polyester laminate--it's called "Bondo".
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