Carbon fiber mast tutorial = push pole?

[Bayport_Bob]

I agree, the process I use is not for the average builder. I posted it for those who have the capabilities or feel they're up to the challenge. I probably have about 30 feet in wasted, finished tubing (& one mandrel) before I had the technique down. The steps I described are the results of my lessons learned and may shorten the learning curve for others. (If anyone has more questions, shoot me an email and I'll help you as much as I can)

I was on the verge of producing paddles commercially, but the price of carbon fiber tripled (and then some) which killed my profit margins and the project.

Thanks for checking out the blog. I'll post pictures both on my site & here as the FS18 project progresses.

[anonymous]

Wow, exellent replies fellas. Thanks for the feedback. Bayport Bob, nice method, it seems you have alot of r&d in this and have it figured out pretty well. What wall thickness worked best for a 7' mandrel? I really like the heat shrink method at the end, it's like vacum bagging but different - where did you source the heat shrink in that diameter (1.5")? I have only seen it in very small diameters. Also, I'm guessing that a regular pair of calipers is not quite up to the task of measuring tolerences of .003". On a side note, I lived in Clearwater for about 10 years and have a few greek friends up your way - the food is exellent. I bet there's alot of snook up the anclote right now.

Shine, I'm not quite visualizing your method. The pvc mold is on the outside? If so what's on the inside to hold its shape? I'm versed on the conduit/pipe insulation method, but fear too much sagging making for a wierd looking pole.

Reguardless of the method, either way is way more appealing than spending $700 -$1000 for a production unit.

[anonymous]

Sorry, that was me in the last post.

thanks for any further input,
Mike Strange

[roob76]

on the insulation foam over conduit method. to keep the pole straight hang it straight up and down while it's curring. this will heep it from sagging and giving odd shaped poles.

also i have not tried this method yet but to laminate three layers wet on wet at once you can slide your fisrt sock over the mandrel and pull it tight now slide your second layer over the mandrel and pull tight and agian with your third layer. now secure one end with a zip tie or tape tightly(you want to have a little material overlapping the foam mandrel so you can secure it to the conduit). now loosen the third layer of sock and peel it back inside out over the part that is secured and the same with the second layer. now you can wet out the first layer then work the second layer back over it and wet out and then again with your third layer. once all layers are wet grab it with a glove and squeeze from the middle out to get out excess resin and to make sure all layers are tight together. now you can hang it so it stays straight. you will need to drill a whole on one end of the conduit and put some string through to hang it on a hook .

[Bayport_Bob]

Mike, send me an email. I think you can see the email button at the bottom of my post.

As for measuring the diameters accurately, I have a $15.00 digital caliper from harbor freight that works like a champ and an old starrett micrometer I use. The main thing is to measure the diameter in several places along the mandrel. The mil spec tolerances for 1.25" diameter tubing is +/- .005 inches. So I incorrectly stated my previous numbers. The key to the process is using enough vaseline on the mandrel This not only creates some lubricant for sliding off the finished part, but it creates a filler under the mylar that will make up for the minor tolerance issues along the mandrel. Also, epoxy resin shrinks ever so slightly when cured (~2%) and the vaseline adds a enough margin to allow for all the possible scenarios that may bind the carbon shaft onto the mandrel.

Another technique to remove the mandrel is to use aluminum's expansion/contraction properties when heated & cooled. I haven't tried it, but if you get one stuck, you might pack the ID with some ice to shrink the aluminum ever so slightly. However the vaseline will thicken on cooling so they may counter act each other.

The minimum wall thickness I would consider for a mandrel would be .083" on a 1-1/4" dia. tube. Remember - don't buy pipe! The tolerances are much looser on pipe and there's usually a prominent seam.

Onlinemetals.com has 8', 1-1/4" OD, 6061-T6 tubing for $32.37 plus shipping. Any lengths longer than 8 feet and you run into an oversized container penalty when shipping. Onlinemetals ships in very sturdy cardboard tubing. I've never had a problem with shipping damage - yet!

You'll also need a mandrel for a ferrule or you might be able to buy pre-made ferrule kits from some of the push pole suppliers. Many times they ship poles in sections that you bond together. They also sell these as repair kits for when you break a push pole. Do a search for Northstar or Loomis push poles. They sell ferrules for ~$20 each. This would probably be cheaper & obviously faster than making your own ferrules. As long as the OD of the ferrule matches the ID of the pole, you're golden.

Cabela's sells the forks and pointed ends at a very reasonable price (~$21 for the pair, plus S&H).

As you can see, I've done a lot of research, testing, & building on these. But I'm keeping my day job!

I spoke with Jacques & Joel on Wed. concerning a hybrid carbon/fiberglass poling platform. They sparked an idea I have for the doing the support tubing in sections, including the curved pieces. This would use the same braided sock material used for push poles. The technique I'm considering uses a process very close to what I've already described. When I have time, I'll make a few curved segments which will be the more difficult portion. If everything works, then I'll post my method. The FS18 I'm building will take priority over the platform testing.

[Evan_Gatehouse]

One further way is to use styrofoam as the mandrel and then dissolve the foam with a few eyedroppers full of gasoline.