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Advice, please: new mast for Seablossom

  • 16 Jan 2012 19:36
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    Reply # 800253 on 788093
    Anonymous member

    This being a mast thread, does anyone out here have experience with carbon fibre? Everybody telling me it is far out pricewise, but I recon I can have one made in the region of 4000- 6000 GBP. The problem is wall thickness. As no compression loads is present, I can use spun tubes, either standard, glued in steps, or a tapered pole aprx. 13 meter high.

    Ketil 
  • 15 Jan 2012 20:38
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    Reply # 798249 on 788093
    Anonymous member
    And unless you can find a tapered tube, you will have extra windage aloft as well as a rather unaesthetic result.  If you've got the quality of timber, time, space and skills to build the lower two-thirds in wood, why not just go the whole hog?

    And I see you are from BC.  The attraction of the composite mast for most of us is the difficulty and expense of getting decent timber.  Hardly likely to be a problem for you!
    Last modified: 15 Jan 2012 20:41 | Anonymous member
  • 15 Jan 2012 15:10
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    Reply # 798088 on 798011
    Deleted user
    Karlis K wrote:Just having a thought: any comments on a upside-down fantail composite mast, with wood laminate from the step to 2/3 of the way up, and some kind of aluminum to bring it to the full height?   Any advantages there in strength, cost, weight aloft?
    Having timber at the bottom means making a bi-conical shape which is a more complicated build. Quick and easy construction to me is the point of a composite mast. 
  • 15 Jan 2012 09:10
    Quote
    Reply # 798011 on 788093
    Anonymous member
    Just having a thought: any comments on a upside-down fantail composite mast, with wood laminate from the step to 2/3 of the way up, and some kind of aluminum to bring it to the full height?   Any advantages there in strength, cost, weight aloft?
  • 09 Jan 2012 20:50
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    Reply # 790726 on 789751
    Anonymous member
    Gary King wrote:Luv what you've done with the colour scheme Annie. Getting away from plastic boat "any colour you like as long as it is white" philosophy makes it look it was designed for the junk rig, rather than an after thought - if you know what I mean.

    I know exactly what you mean.  And thanks :-)
  • 09 Jan 2012 17:09
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    Reply # 790571 on 788093
    Deleted user
    Maybe I'll just stay with what I've got.  I sawed some hunks out of it with a Sawzall trying to cut away the glue but it could be worse.  This autumn I filled them in with thickened epoxy, but that doesn't give me longitudinal fiber strength.  However, I should be able to run my power plane along the mast from maybe a foot above the damage to a foot below it, giving me a shallow relief, and then epoxy in glass tape into that relief.  That way I should have fibers able to work in tension and compression.
    The damage will no longer be at the partners, either, because with the new rig the bury will be reduced about 8 inches as the mast is moving from mid-cabin to foredeck.  It will no longer be in the middle of the saloon, either, so its excessive circumference won't matter much.
  • 08 Jan 2012 11:45
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    Reply # 789751 on 788093
    Deleted user
    Luv what you've done with the colour scheme Annie. Getting away from plastic boat "any colour you like as long as it is white" philosophy makes it look it was designed for the junk rig, rather than an after thought - if you know what I mean.
  • 08 Jan 2012 10:10
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    Reply # 789733 on 788093
    Anonymous member
    In the 'for what it's worth' category - when I picked up my joined-together mast - 6m base, 4.5 top, 0.4 bury - the balance point was quite well below the join.

    'Chuffed to death with the rig' translates to 'the rig is sweet as'.

    :-0
  • 08 Jan 2012 03:21
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    Reply # 789635 on 789457
    Deleted user
    David Tyler wrote:
    Is the wooden mast really beyond saving? The good thing about wood is that you can plane off the damaged area, epoxy on some more, similar wood, shape it back to the original diameter, and it will be at least as good as new.

    If Jeff's mast is missing chunks at the partners, I wouldn't try to save it. Epoxy isn't *that* strong.
    Last modified: 08 Jan 2012 03:22 | Deleted user
  • 07 Jan 2012 19:21
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    Reply # 789457 on 789373
    Anonymous member
    Jeff McFadden wrote:I can get a 35 footer, 6 inch at base, .125 thickness, tapers to 3.5" top diameter, rated for 91 mph "flagged".  I have not yet found one with thicker wall.  Comments?

    Jeff
    Not thick enough, Jeff, I'm afraid. You're looking for 6 inch by 3/16 as a minimum, if the spec is good, with a high temper. Flagpoles have to be rather soft, to spin the taper in, and there, you'll need 7 inch by 3/16.

    Is the wooden mast really beyond saving? The good thing about wood is that you can plane off the damaged area, epoxy on some more, similar wood, shape it back to the original diameter, and it will be at least as good as new.

    If it is beyond saving, then the composite alloy/wood mast has much to recommend it, and is in no way second best to an all wood, or all alloy mast. I made one in about 1977, used it until 2000, and I believe it's still in service. Annie made hers, and is happily sailing about with an entirely serviceable mast. 

    I'm looking up at my two alloy flagpole masts, and I note that the bottom half is parallel; only the top half is tapered. Armchair theorising about taper doesn't carry you very far in the real world. You have to use what you can buy, or make.
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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