Sleeving an aluminum mast

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Anonymous (not verified)
Sleeving an aluminum mast
Well, Vaea is back in the water, but I'm not sailing yet :( There was some rot in the upper portion of the mast, near the blind sheave. Vaea's mast is somewhat of a hybrid: the upper 3' and the first 5' are wooden according to plan. The central portion is aluminum: this is how it came to me. The lower wooden part is still in good shape, and eventually I will replace it with aluminum, but I want to go sailing this summer :!: :!: But I did order some 1/8" x 5" tube to do the top. Here's a shot of the mast at the left (looks bigger due to being closer to the camera), the sleeve (with the "serrations") and the mast top: [img]http://farm3.static.flickr.com/2470/3705130063_391bebd85e_b.jpg[/img] The "serrations" are to prevent any stress in the outer tubes that the edge of the sleeve could produce. I doubt that the wingsail rig would actually stress the mast that much, but it only took 30-45 minutes with my angle grinder and a metal-cutting wheel. I cut the holes for the crane and the jib halyard box today, so all that is left is to drill the lower mast, set the halyard exit plate, and fish the jib halyard up the mast. When will it ever end? :lol:
Anonymous (not verified)
Re: Sleeving an aluminum mast
Kim Thats an interesting sleeve setup. Do you use just epoxy, thickened or otherwise, to glue it together; or do you rivet as well? Dan
Anonymous (not verified)
Re: Sleeving an aluminum mast
Dan, I'm going to use some form, either rivets or screws, of mechanical fastener plus a "soft" adhesive. Here's a photo that shows the rule of thumb for sleeving that an engineer posted on Sailing Anarchy: [img]http://farm3.static.flickr.com/2624/3705468585_ecb02d10b3.jpg[/img] Must go sailing! :lol: BTW, the sleeve requires an 1 1/4" wide slot cut out lengthwise in order to allow it to be compressed to the inner diameter, 4 3/4", of the main 1/8" x 5" tube.
Anonymous (not verified)
Re: Sleeving an aluminum mast
Here's the sleeve being compressed for actual fitting into the new mast top: [img]http://farm4.static.flickr.com/3451/3718103028_14dc2a5613.jpg[/img] The SS hose clamps work great for compressing the 1/8" x 5" aluminum tube sleeve.
Anonymous (not verified)
Re: Sleeving an aluminum mast
Thanks for your post, I have been trying to find a sleeve to extend my mast by 3 ft and could not find the tube with the right diameter. I have a question. How do you cut the 1/4" slot? Thanks!
Anonymous (not verified)
Re: Sleeving an aluminum mast
rhapsody, I used a flexible tape to measure the inside circumference of the pipe, then subtracted this from the outside circumference. To this figure I added 1/4", so the slot turned out to be 1 1/4". I cut the slot on my table saw, using my wooden sled that slides in the miter gauge slots. The sleeve happened to be just the right length to fit inside the fences, and I screwed guide strips on either side of the sawblade opening to mark the location of the left and right cuts. I then held the pipe firmly against the rear fence while pushing the sled through the sawblade. Carbide-toothed woodworking tools cut aluminum easily. The workpiece must not be allowed to move while being cut; if the piece moves out of alignment after cutting begins, things can get ugly, ie, kickback. As long as the workpiece is firmly clamped, or otherwise held in place, it is a simple operation.
Anonymous (not verified)
Re: Sleeving an aluminum mast
Kim, that's a pretty nice sleeve job there. David www. boatsmithfl.com
Anonymous (not verified)
Re: Sleeving an aluminum mast
Thanks, David. Here's a shot of the nearly finished product: [img]http://farm3.static.flickr.com/2464/3731840561_a61ce5d685.jpg[/img] I got the 1/2" x 6 1/2" SS hex bolt and neoprene-backed washers to keep the SS and aluminum separated from McMaster-Carr. I also have some goo in a syringe that Brion Toss recommends for preventing corrosion between dissimilar metals, the name escapes me at the moment. edit: Tef-Gel is the goo's name :) [url]http://www.tef-gel.com/index.html#[/url]