Galion 22 conversion

  • 02 Nov 2017 08:24
    Reply # 5498455 on 5070195

    I never like to mix materials that have different mechanical properties in this way, to carry the same kind of load at the same time. They might, or might not, reinforce each other. It's different in the case of, for instance, steel reinforced concrete, or glass reinforced plastic, where one material carries tension, the other carries compression. Here, you're asking both materials to carry tension on one side, compression on the other, as the mast flexes. But I don't have a definitive answer on this, either on theoretical grounds or from practical experience. It might work, I don't know, and the only way to find out is to try it. It would be necessary to use a timber with compressive strength equal to tensile strength, which means not the lighter softwoods. 

  • 02 Nov 2017 07:23
    Reply # 5497666 on 5070195

    How come it always happens that it's just what you need that is not available? There is not 3mm or 4mm tube available in more than 150mm diameter.

    A few steps back: did you advice me to totally forget the tapered al-flagpole option (145/2.5-2.8 mm with 2.8 meters of parallel) even with a wooden inner mast at the parallel part? The wall just isnt thick enough?

  • 01 Nov 2017 19:48
    Reply # 5490906 on 5070195

    Because you're aiming to go with a high AR rig, I believe you'll need the strongest, and more importantly, the stiffest of those options. That's the 140 x 5. My 165 x 3 mast is a little stronger and stiffer and a lot lighter, because of the thinner wall and greater diameter, and that's what I'd prefer you to have, but if it's not available in Finland, then 140 x 5 is a reasonable choice.

  • 01 Nov 2017 06:19
    Reply # 5481708 on 5070195

    Due to almost nonexistent availability of tapered al-poles in Finland, I have to go with a straight tube and the top made of something else.

    The options seem to be 130x5 and 140x5, no 140x4 (David’s suggestion) available. I suppose the 130 is not strong enough?

    Edit: 150x3 is also available.

    Last modified: 01 Nov 2017 06:35 | Anonymous member
  • 14 Sep 2017 14:16
    Reply # 5232157 on 5227569
    David Tyler wrote:

    Yes, depending on the spec of the GRP. But if this is possible, then  it is also possible to use that portion of the aluminium flagpole that has a diameter of 140 at its bottom end, and make a joining sleeve or spigot.That would be better, but rather wasteful.

    ¨...and too expensive, considering the waste. I can get my hands on cheap grp flagpoles. If I remember right, one of the members has done this to a 20" Havsfidra.
  • 14 Sep 2017 13:30
    Reply # 5227569 on 5070195

    Yes, depending on the spec of the GRP. But if this is possible, then  it is also possible to use that portion of the aluminium flagpole that has a diameter of 140 at its bottom end, and make a joining sleeve or spigot.That would be better, but rather wasteful.

  • 14 Sep 2017 10:35
    Reply # 5213400 on 5210436
    David Tyler wrote:

    I've just done some figuring, and 140/4 is coming out OK, as the lower tube on its own, so long as it is T6 temper. Could you accept this, with a wooden topmast?

    I would, gladly - but estimating from the first sketches I need a 9,5-10 m mast to keep the AR high enough, which in turn would mean 4 meters of wood (the al-tubes here are sold as 6000 mm). I'm not sure if this is achievable by myself.

    How about a 4m grp flagpole plus this 140/4 tube?

    Last modified: 14 Sep 2017 12:55 | Anonymous member
  • 14 Sep 2017 10:03
    Reply # 5210436 on 5070195

    I've just done some figuring, and 140/4 is coming out OK, as the lower tube on its own, so long as it is T6 temper. Could you accept this, with a wooden topmast?

  • 14 Sep 2017 09:15
    Reply # 5206737 on 5201606
    David Tyler wrote:

    So, is the outside diameter 145, and not 150? Quite likely, as there is a Nedal tapered tube at this size. If so, I'm not so sure that it's a good idea to use it.

    If it is indeed a Nedal tube, is the next size up available, 165mm? That's the size that I have. If so, your troubles are over.


    No, it's not a Nedal tube, but a finnish-made one :/


    Oh dear, back to square one.

    Last modified: 14 Sep 2017 09:15 | Anonymous member
  • 14 Sep 2017 08:12
    Reply # 5201606 on 5070195

    So, is the outside diameter 145, and not 150? Quite likely, as there is a Nedal tapered tube at this size. If so, I'm not so sure that it's a good idea to use it.

    If it is indeed a Nedal tube, is the next size up available, 165mm? That's the size that I have. If so, your troubles are over.

    Last modified: 14 Sep 2017 08:35 | Anonymous member
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