Carbon Fiber rods

[rasby]

Can anyone tell me if the carbon fiber material they make archery arrows with is the same strength as material typically sold at Stew mac etc.. If it is, do you think the round shape if seated in a core box routed channel covered with a wood fillet would be good.



I am trying to straiten a cheap mandolin neck with alot of upbow, remove the finger board, plane out bow, and rout and epoxy CF etc.. needless to say no truss rod in it.

any advice appreciated

I have a cheap source of old arrows locally.



thanks



rasby

[AaronVW]

I think that archery arrows are hollow? Most carbon fiber rods used in instruments are solid. A hollow CF tube would be very light but not sure if it would be stiff enough. A regular 1/4 x 3/8 CF rod is not very expensive....

[rasby]

Thanks Aaron

the owner of the shop said he had hollow graphite arrows and SOLID carbon fiber ones. The CF he said were for practice arrows.

Its not so much the price, but a hankering to do the job now and using something at hand if it is suitable.

[David Newton]

Dragon Plate has very inexpensive carbon fiber "strip".
One piece of 1/8" x 3/8" x 24" long can be cut in half and doubled up, super-glued together.
Cost is $5.53 plus shipping.

[Graham McDonald]

A solid rod should be fine. Sit it down in the neck a bit, so the bottom of the slot is around 1/2" deep and epoxy in a strip of wood on top. Or if you can find a couple of hollow arrows that fit inside each other and epoxy those together. Should do the job as well

cheers

[amowry]

I would think that a single hollow arrow would be too flexible, and rectangular (set vertically) is much stiffer without adding too much weight. Like Graham said, the key is to put it as low in the neck as possible, so it's mostly under tension.

[Jim Baker]

I've used carbon fibre in two necks. The first one failed because I stacked two 1/4" pieces on top of each other. The neck moved over a matter of weeks. I took it out and put in a truss rod. I used cf in another neck but used 2 pieces 1/8" x 3/8" side by side. No problems with that one.

[Wilbur Tabacsko]

Dragon Plate has very inexpensive carbon fiber "strip".
One piece of 1/8" x 3/8" x 24" long can be cut in half and doubled up, super-glued together.
Cost is $5.53 plus shipping.

Dragon Plate has $30 minimum purchase.

[rasby]

Hey Jim

Thanks for info I haven't been here for a bit to check replies hence the late response. Hows things 2 km down the road?

[Jim Baker]

Hi Fred. Not much going on . This winter I built a cheap classical guitar kit with the intention of learning to finger pick. I think it's going to take a while.

[Paul Hostetter]

I am trying to straighten a cheap mandolin neck with a lot of upbow, remove the finger board, plane out bow, and rout and epoxy CF etc.. needless to say no truss rod in it.

Don't take the board off. Pull the frets and any dots and plane the neck true with the old board left in place. Maybe there's enough board to reuse it with deepened fret slots. If so, the neck will be quite stable.

If there's no board left, then it's appropriate to route a channel (hope there's no dinky steel bar down there!) for a carbon fiber bar. Such a bar needs to be a very tight fit. Your recycled arrow supply will be of no use, I'm afraid. The remains of the old board will be a shim under the new board.

BTW, carbon fiber is embedded in epoxy in the first place. If you decide to double up a thin bar, use epoxy. Most importantly, make sure it's a tight fit and that the bars are aligned as Jim in post #7 says. And look out for the CF dust, it's really bad news.