We are in good company

[Daryl and Daryl]

I like to buy spars from Kites and Fun Things. They are cheap and the service is good.

Kites and Fun Things

I was recently e-mailing back and forth about an order and mentioned I use the spars for tents and backpacks. Here's part of the response I got:

"There is a company called zpak that uses our tubes for shelters and backpacks."

It's nice to know I'm in good company.

[Sam Farrington]

Daryl,
K&FT is selling spars from Skyburner, which also makes the SkyShark spars, like the P400 that you have mentioned in posts.

The Skyburner site is up front in acknowledging that the spars are made from a woven carbon material that is wrapped around the mandrel like a cloth.
This process is much better than pultruded, but does not yield as strong a spar as the best multi-layered wrapped ones. I've mentioned the layered Victory V-Force V6 arrow shafts before, which I've found to be markedly stronger than the P400s.

The Gold Tip XT Hunters, size 75/95 with 5 layers (of carbon, not fillers or finishes used by Easton, Cabelas, Carbon Xpress and others) are both stronger and lighter than the Victories, but more expensive, around $75 @ dozen.
I have break-tested all of the above mentioned. It is interesting that the P400s break with a 'thunk' sound, while the stronger wrapped layered carbon breaks with a crack.

I used a very simple set-up:

The scale is pulled down by the handle and indicates the pounds of force exerted at the moment of the break. The scale attachment point must always be exactly the same distance from the lip of the ALU tube protruding from the brick wall; otherwise, the change in leverage would vary the results. The breaks always occur at the lip of the tube.

What also varies the results is the snugness of the protruding tube over the carbon spar. So the tolerance between the inner diameter of the tube and the outer diameter of the spar is kept to between one and two one/thousandths of an inch. Even that variance will alter the results, but it is the least that is practical to create.

The XT Hunters might be a bit too stiff for your purposes; but if not, please try them and see if you agree. The Victories are available in several flexes, including those designated 400, 350 and 300. I use the 300s, and they are flexible enough to span a 7.5 foot arc with a height of around 4 feet, to make poles for a Wilderness Equipment Bug Dome. About the same stiffness as an Easton .340" OD 7075-T9, which is around twice as heavy as the carbon.

The Victory 300s are stronger and heavier than the more flexible 350s or 400s, because they use more layers of carbon to achieve the stiffness. I don't know if that is true of the XT Hunters, but suspect it would be.

Hope this is of interest.

[Daryl and Daryl]

Samuel,

Thanks for all the info. Very interesting.

I'm a bit overstocked on shafts at the moment so I probably won't be buying anymore for awhile.

Thanks,

Daryl

[Jerry Adams]

You've drilled holes in your brick wall so you can test shafts?

[Sam Farrington]

It worked for me, Jerry. Guess it is all about passion for the MYOG, and not wanting to waste a lot of time on something that will turn out inferior to store-bought.
They are just two small holes, though, and the brick is just a facia, behind which is the real wall of the house. The holes are in the mortar, not the brick, and could be filled easily with mortar mix. No sweatsky!

[Jerry Adams]

I have a hole through my exterior wall between insulation measuring instrument and my computer.

The wife complains about it occasionally but mostly just ignores it.

I kind of put it behind the barbequer so you can't see it too much.

[Daryl and Daryl]

Your holes through/in the walls sound like answers to the question "You know if you are an ultra lighter when…….."

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