Mast Partner Design for JR

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  • 24 Mar 2015 00:25
    Reply # 3263420 on 3223038

    Round in section, certainly, but I can't answer as to hardness. Not foamed, but solid elastomer is all I can say

  • 23 Mar 2015 17:58
    Reply # 3262983 on 3223038
    David, the rubber doughnut: round in section and soft, say 60 or 70 shore?
    Last modified: 23 Mar 2015 17:59 | Anonymous member
  • 23 Mar 2015 16:25
    Reply # 3262851 on 3262629
    Ben wrote:

    Gerald,

    Are you talking about the mast boot that seals the weather out or a rubber gasket that supports the mast at the partners?

    May I answer that, as I fitted out Ivory Gull? The rubber doughnut is purely for mast support, and there is a boot as well. 
  • 23 Mar 2015 16:12
    Reply # 3262837 on 3223038
    Deleted user

    Wow......you can't beat the service on JRA! Thank you!

  • 23 Mar 2015 15:51
    Reply # 3262675 on 3223038
    Anonymous

    Done.

    Chris

  • 23 Mar 2015 15:09
    Reply # 3262629 on 3223038
    Deleted user

    Gerald,

    Are you talking about the mast boot that seals the weather out or a rubber gasket that supports the mast at the partners?

    Thank you Annie for your experience with your raked mast. That helps.

    Maybe someone qualified to do so, could change the title of this topic to "mast partner design" which covers a broader spectrum.


  • 23 Mar 2015 10:12
    Reply # 3262254 on 3261587
    Gerald O'Brien wrote:

    Ivory Gull's foremast is raked forward slightly. The seals at the partners on both masts are formed by rubber compressed between two plywood plates. This gives excellent non-leaking seals which are also silent.

    Gerald, I like this idea. How thick are the rubber doughnuts, how flexible is the rubber and is it round in section, or square? Does water lying inside the upper plywood plate raise the possibility of corrosion in an alloy mast? I'm about to construct partners for my masts and have yet to decide whether to use this idea, or to form a seal of Spartite, or pourable polyurethane, (after coating the partners with release agent), as David Tyler advocates. 
  • 23 Mar 2015 01:20
    Reply # 3261705 on 3261518
    Ben wrote:

    All good input, thank you!

    Annie what are lolly sticks?

    If you are from USA, Ben, I think you'd call them Popsicle sticks.  Like tongue depressors but about 115mm x 10mm x 2mm thick and made out of wood.

    Does anyone have experience with a raked foremast partner? With the slight upsweep of the deck at the bow, combined with the forward rake of the mast the opening at the partners will be more of an oval.

    Fantail has a strongly raked mast and the partners are at the same angle to their base.  If I had been a sufficiently clever woodworker, instead I would have made an angled plinth so that the (stainless steel) partners would have been at right-angles to their plinth.  That would have been a lot cheaper.   And if you are building the partners out of anything else, I still think that would be the better way to go.

    I was thinking I would lay up the partners with an opening just big enough for the mast to pass through, step the mast and scribe lines off the mast from above and below. Then remove the mast and remove material down to the lines.

    Do you rake the step as well and keep the mast square to its length at the foot?

    I put in the mast step horizontally and sawed a little off the base of the mast to match the angle.  Supposedly, this will also have a 'cam' effect to stop the mast from rotating.  But I also fitted a rigging screw between two saddle eyes - one on the step and one on the mast, both to hold the mast down and to prevent it rotating.

    Or should I make a new topic with this raked mast partner questions?

    If you want to discuss this any further, yes, we should probably start a new thread.
  • 22 Mar 2015 22:15
    Reply # 3261587 on 3223038
    Deleted user

    Ivory Gull's foremast is raked forward slightly. The seals at the partners on both masts are formed by rubber compressed between two plywood plates. This gives excellent non-leaking seals which are also silent.

    Last modified: 22 Mar 2015 22:18 | Deleted user
  • 22 Mar 2015 20:24
    Reply # 3261518 on 3223038
    Deleted user

    All good input, thank you!

    Annie what are lolly sticks?

    Does anyone have experience with a raked foremast partner? With the slight upsweep of the deck at the bow, combined with the forward rake of the mast the opening at the partners will be more of an oval.

    I was thinking I would lay up the partners with an opening just big enough for the mast to pass through, step the mast and scribe lines off the mast from above and below. Then remove the mast and remove material down to the lines.

    Do you rake the step as well and keep the mast square to its length at the foot?

    Or should I make a new topic with this raked mast partner questions?

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