splicing aluminum tube with a sleeve insert

Discussion in 'Boatbuilding' started by Charly, Oct 3, 2013.

  1. jonr
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    jonr Senior Member

    After all of that and you are still quoting the wrong alloy? The chart confirms what I wrote exactly. No UTS values and no sales literature.
  2. Ad Hoc
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    Ad Hoc Naval Architect

    My apologise, force of habit with using 5083 all the time.

    However, I still don't see where you mention the differing values with different tempers though. That's the important part.
  3. nimblemotors
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    nimblemotors Senior Member

    plug weld

    I would assume the tubing is way overbuilt already, as steering on boat is pretty much second only to hull leaking in importance. A little weld isn't going to matter. It is just going to create a little more weight with a sleeve. Personally at this level of boat, I'd get new tubing the right length. You will find other uses for the 8ft tube.
    Where do you live that you can't get it locally???

    What I did for my car suspension aluminum tubing is weld in some solid tubing that fit inside the hollow tube, I made on my lathe to be a tight fit. plug welded, so no stress seam.
    If you don't want to weld it, can make it an interference fit, heat up the tubing, insert the cold piece in. Just for good measure then drill small hole and run bolt/pin through both.
    Did that for my car steering shaft. :)

    This advice is worth what you paid for it..

    plug weld:

  4. Charly
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    Charly Senior Member

    Thank you all for the feedback.

    Nimblemotors, I was thinking I'd maybe do something similar, without welding- just find a tight fitting sleeve, prep the inside of it and fill with a plug of epoxy/microballoons/fiber, and after cure drill a hole all the way through it, then insert an aluminum pin all the way through, and peen both ends up snug. maybe bed it in 5200 or more epoxy before peening to take care of any "slop" if the hole is not perfect. I am out of my element with aluminum so any advice is appreciated.

    Then again I could just drive down to Orlando...
  5. dinoa
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    dinoa Senior Member

    Drive down to Aircraft Spruce http://www.aircraft-spruce.com It's closer.
    If you want better corrosion protection anodize it then seal by boiling it in water for 30 minutes.

  6. cor
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    cor Senior Member

    I once fixed a broken mast on a dinghy that was made from a round aluminium extrusion. Someone else had previously tried to repair it with welding it and it broke again in the heat effected zone.

    I had a piece of tubing of the same size on hand, I split the tubing length wise so that I could squeeze it down and fit it inside the mast. I held this new sleeved in place with epoxy and rivets. It has worked fine for many years.

    Of course the consequences of failure on a dinghy are a lot different than failure on a large cruising boat.

  7. tom28571
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    tom28571 Senior Member

    Is this application not straight axial tension and compression? No bending?

    An internal sleeve glued and riveted will surely suffice in such a simple application. Masts and booms have been extended or repaired this way for many years with success.

  8. Easy Rider
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    Easy Rider Senior Member

    I agree w dinoa.

    Aircraft Spruce will have lots of 6061 and if you get the right wall thickness they sleeve very well. Not a tight fit but close to snug. Most hang gliders and ultralight aircraft are based on aluminum tube frames bolted together with numerous sleeves. One could use some 3M5200 inside to keep the sleeve in place so no holes need to be drilled. But most ultralights have holes for the bolts and are trusted while in flight. I have 2000 hrs on such airframes. You could put the sleeve in the end of the tube w less stress. You just need a sleeve w the OD of your tubes ID or the ID of your tubes OD. If you do it w/o holes and hold the sleeve in place w flexible adhesive/sealant it will probably be stronger than w/o the sleeve.
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