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Yachting World 5 tonner -- possible conversion

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  • 01 Mar 2025 09:41
    Quote
    Reply # 13469301 on 13457716
    Anonymous member

    Thanks Tony, and Annie, for your estimations of mast weight. It's very reassuring.
  • 28 Feb 2025 06:01
    Quote
    Reply # 13468891 on 13467902
    Anonymous member
     
    Anonymous wrote:

    Thank you Annie. You're right, GRP wouldn't be a good idea. However, carbon fibre would work, if i could find one. Much stiffer.

    My problem would be manhandling a solid piece in my reasonably small space. My workshop is 20' long so I was planning on making a little door/flap at one end and I could saw pieces that weren't ridiculously heavy, and glue up in jigs.

    I realise that whatever method I use it's going to be very heavy when finished. Do you think 3 or 4 people could lift and carry the average 10m mast?

    Cheers.


    Pete and I could (just) lift Badger's masts, which were solid and about 11 m +/-.  If we were moving them about seriously we could grunt it with three people and manage fairly well with four.  The two of us could very easily carry Missee Lee's square, hollow, douglas fir mast, which was about 7m long.  I can't recall its cross section. My hollow topmast on FanShi, 4.5 m long, was perfectly easy for me to pick up and carry.  It tapered, over that length, from 154 mm to 90 mm.
  • 26 Feb 2025 17:14
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    Reply # 13468032 on 13467902
    Anonymous member

    Do you think 3 or 4 people could lift and carry the average 10m mast?

    Cheers.


    Yes.

    There's a calculator here that will give a good approximation of mast weight.

    https://jrcalc.oscarfroberg.com/
  • 26 Feb 2025 14:44
    Quote
    Reply # 13467902 on 13457716
    Anonymous member

    Thank you Annie. You're right, GRP wouldn't be a good idea. However, carbon fibre would work, if i could find one. Much stiffer.

    My problem would be manhandling a solid piece in my reasonably small space. My workshop is 20' long so I was planning on making a little door/flap at one end and I could saw pieces that weren't ridiculously heavy, and glue up in jigs.

    I realise that whatever method I use it's going to be very heavy when finished. Do you think 3 or 4 people could lift and carry the average 10m mast?

    Cheers.
  • 26 Feb 2025 00:32
    Quote
    Reply # 13467731 on 13457716
    Anonymous member

    Go and observe a GRP flagpole in a strong breeze.  They bend like bamboo!

    our member Pol Bergius runs a timber yard.  While he's in Scotland, so not exacly handy, he might have some wood that would suit for a topmast and he would at least understand what you're talking about!!

    I enjoyed making my 8-sided mast, but it would be far more logical to get a piece of wood of around the correct dimensions, saw it in two, hollow it out for any wires you might want to run and to reduce the weight somewhat and then glue it back together (end to end?) before shaping it.  Douglas fir would be my personal choice.
  • 12 Feb 2025 18:08
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    Reply # 13462315 on 13457716
    Anonymous member

    Thanks David. I don't know what I can get yet. I don't think there's anywhere local. I used to get my timber from Timbmet in Oxford but the delivery will be costly. 

    I just got a quote from Aluminium Warehouse for a 5m length of 6063 T6 200mm dia,  5mm thick tube. £820 + VAT.

    I was thinking a GRP "extra heavy duty" flagpole might be sturdy enough, but maybe not.
  • 12 Feb 2025 12:28
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    Reply # 13462129 on 13457716
    Anonymous member

    I'd prefer something a bit harder and more rot resistant - douglas fir, larch, cypress etc, but it should be a pragmatic decision - what can you find locally at a good price, perhaps a recycled spar, perhaps a tree straight out of the forest?

    GRP doesn't make for a good unstayed mast - heavier and more flexible than its rivals. But if you can find a tapered tube that would make a topmast for an aluminium tube, it's a possibility.

    CFRP makes a good, if expensive mast for lightweight boats, but is a little over the top for a heavy displacement carvel boat, I feel.

    Last modified: 12 Feb 2025 13:01 | Anonymous member
  • 12 Feb 2025 12:16
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    Reply # 13462126 on 13457716
    Anonymous member

    Hello David, nice to hear from you. A hybrid certainly seems to be a good idea. I've put out a couple of enquiries for quotes on aluminium tube spec. as you suggested and also fibreglass flagpoles from Harrisons. Would you use spruce for the top bit (assuming I can get good quality clear spruce)?

    I like the idea of a composite carbon fibre or GRP mast.

    Sorry to hear you've hung up your sails but I guess you've done a good few miles!

    Cheers.
  • 11 Feb 2025 15:18
    Quote
    Reply # 13461701 on 13461179
    Anonymous member
    Anonymous wrote:

    Graham, thanks for that, re. mast. It sounds like it may need a good helping of luck to find the right thing. Yours sounds perfect. One problem I may have is that where we live, the last few miles are single track roads with grass growing up the middle. We can't get big trucks down here so it may be difficult getting something delivered in one piece.

    I'll give David a shout and see if he has any more ideas. We met up in Scotland a few years ago when we did some testing with Alan Boswell of the differences between Weaverbird and my conventional rigged boat Calisto

    Whenever there's any difficulty in procuring a one piece aluminium mast, I always come back to recommending a hybrid aluminium/timber construction. You get yourself an aluminium tube, to a stronger spec than with the tapered aluminium poles, 6082T6 or 6061T6, rather than 6063; so your factor of safety can be higher - more strength for a given stiffness. Try to find a 6 metre length. Then make a ½-barrel-tapered timber topmast (6- or 8-staved for preference, when the facilities and skill level are present, as I'm sure they are here). 
  • 11 Feb 2025 12:04
    Quote
    Reply # 13461622 on 13457716
    Anonymous member

    Hi Asmat.

    Lucky you. That sounds great. Sadly my boats aren't worth much monetarily so I wouldn't be able to get much if I sold it/them ( I've also got a little Hunter Medina on a trailer outside the house!)

    I never believed that saying that owning a boat is like standing in a shower tearing up £10 notes, but now I certainly do.

    Happy sailing.
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