carbon fibre tube manufacturing

Have any of you made any tubes out of carbon fibre? I presume the tecnique should be similar then fibre glass but I would like to achieve a nice glossy finish with the carbon weave showing.

My mast on my sailing rig on the kayak has failed in 35 knots wind (bending the stainless steel tube with dowel reinforcement in the centre) http://www.flickr.com/photos/gnarlydog/2227853814/.

I am unable to source any ready made 16 mm diameter tubes locally (Australia) and I was contemplating making my own mast that will fit the 16 mm fitting for the kayak deck.

Any suggestions appreciated.

Some detailed instructions here:
http://www.solarcomposites.com/MakingShafts.html

Carbon fiber tubing…
http://www.onlinemetals.com/merchant.cfm?pid=14585&step=4&showunits=inches&id=1057&top_cat=1053



Is this close to what you’re looking for?

not really
I need on OD of 1.5" to replace the stainless steel mast on my kayak sail rig.

The max diameter of tubes on the website that you mentioned are just way too small

(but thanks)

LOL bohemia …
To the mast dude, you can call me if you want experienced help.



(858) 405 - 0652

Composite Engineering
You might want to talk with Ted at www.vandusenracingboats.com, he makes carbon fiber spars

I’m confused
16 mm is about 0.625 inches not 1.5 inches.

Looking at your pictures (very nice pictures I might add) your mast looks closer to 0.625".



I can’t help you with carbon but I’ve had good luck with Aluminum tubing. My canoe mast is three 5’ lengths of .058" wall 6063 tubing 1.375", 1.25", 1.125". It carries 50 square ft of sail no problem.

I get it here. http://www.texastowers.com/aluminum.htm

Shipping to Oz might be prohibitve but you probably could find similar there.



Good luck,

I thought you said 16mm…
That’s awfully close to .625, the dia. of the product in the page I linked. Good luck.

check out: kitebuilders.com
they have LOTS in different materials and sizes…

I am sorry for the metric conversion
despite that I lived in USA for more then 7 years I never quite got my head around the imperial system. I apologies for the previous comment of needing 1.5". You are correct: 0.625 is very close to what I need.

However I realize that a mast for my sail system of 1.4 mt (I prefer to continue on the metric since I find it a bit more “logical”… no offence) is not going to be an easily shippable item if I purchase such thing in USA. That leaves me with the option of manufacturing the thing myself. Sourcing carbon sleeves locally is again pretty much impossible but shipping the raw woven carbon from USA is ceratinly feasible.

Maybe just wrapping a very light wooden dowel with several carbon sleeves might have to do the trick.

Gnarlydog

Sails
Nice pictures.

I have absolutely nothing to offer here, but wanted to ask who makes the sail rigs shown in the photos? Very nice rigs.

I design the rigs
but I have a sailmaker cut the sail cloth. It woudl cost me more and take too much time to cut and sew the sail.

The similar commercially available rigs have several design flaws and certainly can not sustain more then 20 knots winds.

My mast failed for the first time since I tried to sail in 35 knots. Admittedly I was not very confident on the my new lighter mast in stainless steel, hence I now am looking at a carbon job.

The stays are in Dyneema cord (rated at 1050 Kg). If the deck of the kayak is rather soft it must be reinforced with a fibreglass rib, on the underside, at the mast base.

Metric conversion
I’m not great at that myself.

This



http://joshmadison.com/software/convert/



is an sweet little application that I keep on my desktop just for that reason.



It’s free too!

35 Knots!
That’s a pretty fierce breeze!

Have you considered going to a larger diameter mast? 16 mm is pretty thin IMO.

If I was doing it I’d probably start aound 25 to 30 mm (roughly 1 - 1.125 ") reguardless of the material.



Broken windsurfing masts might be a cheap source?



I’m guessing you have seen Larie Ford’s stuff?

http://www.laurieford.net/sails.htm



In your pictures it looks like at least one of the boats has no rudder. Is there a big difference in handling that vs. a ruddered boat?


Carbon masts
I was fortunate enough a number of years ago to work with the guy who pioneered Dynafiber windsurfing masts. The technology is to use a bi-axial or tri-axial woven sleeve slid over a mandrel (old aluminum mast) wet out, and oven cured using a rain gutter and Coleman camp stove. Of course Dynafiber went on to become the best windsurfing masts in the world and refined their technology a bit from the above description. Basically the woven sleeve works like the old children’s Chineese finger that collapses around the mandrel or finger when pulled tight. Adventure Technology paddles uses this same technology in their paddle shafts or Dynafiber is making the shafts for them.

skeg vs rudder for sailing
Tommy, I started off with a Laurie Ford style sail (step mast) and I thought it was great fun but it did not allow me to paddle while sailing: the sail was too close to me since the mast has to be inserted into a sleeve on deck while sitting in the kayak (it must be close to you to be reached). I considered V sails but they are not as efficient and I believe the set up and rigging is a bit primitive.

The current set up uses a tiller extension fitting on the deck of the kayak and therefore 16mm diameter. I guess a larger diameter mast would be better but I don’t know of any other light hardware that would allow me to have the mast collapsible. A carbon fibre mast would ceratinly be strong enough. I had to reinforce the deck of my Assateague with some layers of carbon cloth on the underside of the mast foot ( I had some spider cracking happening after the 35 knots incident).

I used to have the same set up on a ruddered kayak but the skeg kayaks perform better. The extended keel line on a typical skeg kayak helps the kayak from drifting sideways and therefore sail better. Since the sail is mounted faily forward on the deck the force of the wind on the sail cancels out weathercocking. I can control the direction of the kayak by simply deploying more or less skeg. Half way skeg gives me perfect neutral direction. Admittedly a ruddered kayak is somehow easier to manouvre in a tight turn but it does not sail as efficiently.

Unless I have a head wind I can use my sail to cover long distances that otherwise would see me totally buggered.

Gnarlydog

Could you make an adaptor?
I don’t know what your hardware looks like so I might be totaly off but…



I wonder if you could make a plug, maybe 10cm long with half of that fitting into a 30mm mast and the other half turned down to fit your 16 mm hardware?

Just a thought.



Anyway thanks for the pics and getting my imagination cooking. It looks pretty nice down under!

found a local carbon fibre manufacturer
Pacific Composites is willing to manufacture me 3 tubes out of carbon fibre for a very reasonable cost. However the info from you guys has sparked an other project… a carbon fibre Greenland paddle. The carbon fibre biaxial sleeves that are available from http://www.solarcomposites.com/composites/carbon%20fiber%20sleeves.html will make the project viable (I think :slight_smile: even with my limited knowledge with composites construction.

Bird’s mouth shaft
Damiano,



You might find this link interesting: http://www.geocities.com/shawnkayak/paddle/birdshaft.html

I used this method to make the hollow wooden core for my paddle shaft. I used strips of Western Red Cedar to keep the weight down. I also cut them to different widths in order to create an egg-shaped shaft. It worked out beautifully; by far the most comfortable paddle shaft I’ve ever held. I covered the core with a carbon fiber sleeve and used heat shrink tubing to squeeze out the excess epoxy. You don’t need too many layers of carbon fiber/epoxy since you already have a core. I also added a strip of 1.5" unidirectional CF under the sleeve for additional strength/stiffness. I placed this strip along the power-face edge of the shaft so that it would be in tension during hard paddling and extended paddle rolls.



I bought my CF sleeve and heat shrink from Sweet Composites, but for larger sizes, Sollar Composites has a great selection. Both are very helpful and pleasant to deal with.



http://sweetcomposites.com/



http://www.solarcomposites.com/



Good luck,



Pedro Almeida



p.s. The bird’s mouth technique can be adjusted to make any diameter tube you want.