Sectional, sure it is. Just do the sleeve like you mentioned and glue the sleeve to just one of the ends. The rivets will have to go tough, so you must think up something new there. Perhaps laminate the eye to the sleeve instead.
Just get a smaller diameter alu tube that fits inside. 1 mm difference between the tubes is enough and practical. The longer you make the sleeve the more tight the fitting becomes especially when the tube is bend slightly like when you do pretensioning the spi pole.
On landyachts were we use masts that are made up out of at least 3 independent alu sections the sleeved overlaps are nearly always 150 mm. (halve a foot) That seems to work well enough.
In your case make the (internal) sleeve permanent on the pole that takes the eyestrap for the bridle strut. The two bolts or monel blind rivets you use for the eyestrap will also secure the sleeve. Smooth out the ends where the breakage occured by sawing off a small piece and VOILA you have a collapsable spinnaker pole, very nice for transporting the boat.
The pole tip wires will keep the front tube secured to the sleeve by compression.
Hell, come to think of it I might even get such a setup myself. Will allow me to remove the snuffer ring a bag and not have them degrade in the weather 6 months a year.
Wouter
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
Re: loud cracking sound
[Re: Wouter]
#118659 09/27/0710:32 AM09/27/0710:32 AM
Ummm, dare I ask the obvious? How much is a new spin pole?
Not much. The length is 10'+. That is a pita to rig and stow. Since I have lemons, I thought I'd make lemonaide. (The only thing broken is the tube, all the attached hardware is fine. BTW- the original damage is from inadaquate preparation. I was in too big a hurry to get on the water.)
You could start a trend and in a few years all new boats will come with sleeved spi poles.
If it works for landyacht masts (MUCH higher loaded) then it must certainly work for spi poles.
In case my other post wasn't clear enough. In landyacht masts the tricks is as follows.
They only get tubes that have a outer diameter that can be devided by 5 and that have a wallthickness of 2 mm. With these you are always certain that you can find an adequate sleeve in getting a tube that has an outer diameter of 5 mm less then tube you want to sleeve.
1 mm difference = 0.5 mm space on either side between the tubes is practical when the tubes gether salt, dirt or small damaged spots. Probably 0.5 mm = twice 0.25 mm would be perfect but such tubes are not part of the standard extrusion package and therefor are custom orders. And the 1 mm difference setup works out quite well in stiffness and strength already.
If for some reason you want to sleeved tube to sit more straight and more tightly then just use electrical tape to place two bands on the exposed inner tube, spaced something like 100 mm apart. Basically close to either end of the exposed sleeve. This takes out most of the slack. You'll have to experiment a little with the tickness of tape. You can also cover the whole sleeve with tape but this setup can be tricky to seperate if you do it wrong or alot of dirt/salt gets in there. And two bands of tape works just as well as coverong the whole section.
I hope this is clear to everybody.
Hey Tiki,
Just measured my own pole and I can do such a setup myself as well. But best of all I thought of the following. Instead of completely seperating the two sections one can actually just unlock the two tubes and flip the front end over backwards and just store this whole package (incl. the spi that remains in the sock) as one item (in a trailer, sailbad or shed). One can leave the retrieval line and sheets attached. Basically cutting down massively on spinnaker (de)rigging time. Just fit the pole, unfold it and put the front end over the sleeve and then run the top halyard (other end of retrieval line) up the mast. Also the spinnaker can never be tied on wrong ever again.
Wouter
Last edited by Wouter; 09/27/0701:04 PM.
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
You could start a trend and in a few years all new boats will come with sleeved spi poles.
Sounds like an 18 sq I used to sail with. Everytime he broke the mast, he sleeved it. He always claimed he always claimed he was testing and reinforcing the weak points.
Think a carbon two piece sleeved pole is standard on STealth , certainly I got one and its a great boon to break it down and put in box for travelling , 2yrs sailing in all winds has proved it up to the job
It works so far. Keeping it simple, I got a 16" piece of anodized aluminum with a very thick wall and bedded that in with silicon. I decided epoxy was over-kill. I wrapped the joint with rigging tape, because it was thicker and more rubbery and doesn't have the gooey adhesive of duct tape or electrical tape. I didn't fly the spin because there was W-A-Y too much wind for me, but the rig did survive a fairly radical pitch-pole.
I did nothing to the other end, just filed it flat and took off any sharp edges.
$3.00 for the alu sleeve; $1.50 for the silicon; the tape I already had on hand.