S2 6.7 Junk Rig Conversion

  • 21 Oct 2020 07:56
    Reply # 9316544 on 6872873

    This reminds me of when Annie was looking for battens for Fanshi, and the pultruded stock tubing readily available in NZ was found to be too floppy to support its own weight, like this USA stock. This must have been made with random directional fibres as well.

  • 21 Oct 2020 03:35
    Reply # 9316318 on 9316122
    Deleted user
    Anonymous wrote:
    David Th wrote:

    Would you be better off with aluminium battens? I used T5 alloy battens very successfully on the big sail on Footprints. They were light but strong and I never had a failure. Larger diameter with thinner wall thickness seems to produce a reliable batten. But it looks as if you are locked into a diameter based on your already made batten pockets. 

    After reading the other David's message I spent part evening trying to find unidirectional fiberglass tubes. The only ones I can find online are VERY expensive. The remainder of my evening I have been convincing myself that ripping out the batten pockets and replacing them with larger ones might be fun. I think I have all the materials for that effort. At least I do not need to buy anything.

    It is a real bummer to waste all the tubes and epoxy that I put together only a few days ago.

    I don't know how you can quantify this but can you give me some idea how rigid the battens were on footprints?

    The alloy battens were the top three on the sail and were 6.5 meters in length and from memory about 65 mm diameter and 1.5 mm wall thickness. To lift them individually there was no flexing, and with the sail up and working there was very little deflection, not really noticeable at all. I know the recommendation is to use T6 alloy which would allow smaller diameter but my T5 battens were fine. I imagine for your sail you would only need 25 to 30 mm diameter battens, but others might be able to advise better on sizing.
  • 21 Oct 2020 00:53
    Reply # 9316122 on 9315933
    David Th wrote:

    Would you be better off with aluminium battens? I used T5 alloy battens very successfully on the big sail on Footprints. They were light but strong and I never had a failure. Larger diameter with thinner wall thickness seems to produce a reliable batten. But it looks as if you are locked into a diameter based on your already made batten pockets. 

    After reading the other David's message I spent part evening trying to find unidirectional fiberglass tubes. The only ones I can find online are VERY expensive. The remainder of my evening I have been convincing myself that ripping out the batten pockets and replacing them with larger ones might be fun. I think I have all the materials for that effort. At least I do not need to buy anything.

    It is a real bummer to waste all the tubes and epoxy that I put together only a few days ago.

    I don't know how you can quantify this but can you give me some idea how rigid the battens were on footprints?

    Last modified: 21 Oct 2020 00:55 | Anonymous member
  • 20 Oct 2020 22:49
    Reply # 9315933 on 6872873
    Deleted user

    Would you be better off with aluminium battens? I used T5 alloy battens very successfully on the big sail on Footprints. They were light but strong and I never had a failure. Larger diameter with thinner wall thickness seems to produce a reliable batten. But it looks as if you are locked into a diameter based on your already made batten pockets. 

  • 20 Oct 2020 21:14
    Reply # 9315567 on 6872873

    Sorry, Scott, I don't like the specification of this tube:

    "This fiberglass tube is made by the pultrusion process. Fiberglass (random directional) mat, pulled via hydraulics through a bath of resin and pigment. Heated and cured. "

    The fibres should be almost all longitudinal, to give maximum stiffness, with preferably a little diagonal braid in the layup to provide hoop strength. You can see this in the tubes that I buy from my preferred supplier. Random directional mat is not suitable for making structural tubes to withstand bending loads.


  • 20 Oct 2020 20:25
    Reply # 9315461 on 6872873

    I could use some help. I think my battens are too flexible. The tubes I glued together for the yard and for the upper most sheeted batten (larger than the others) seem good to me.

    The others seem to bend significantly under their own weight.

    Is anyone willing to guess if the batten I have shown in the photo might be acceptable? If I am going to re-work it I would rather do it at the house and not after it is rigged on the boat.

    The photo shows a one inch pultruded fiberglass tube glued inside a 1.25 inch tube. The wall thickness is 0.125"

    David: Thanks for the information about melting epoxy. I ended up gluing on a second 'hinge' for now. I still need to cut or melt the first one off somehow.

    3 files
    Last modified: 20 Oct 2020 20:34 | Anonymous member
  • 02 Sep 2020 06:21
    Reply # 9206303 on 6872873

    Hi Scott, the 250 to 300 centigrade is the heat gun temperature, the epoxy will fail at around 100 centigrade. This is well below the temperature that may effect the temper of the Aluminium which is between about 180 and 220 degrees centigrade.

    All the best, David.

  • 01 Sep 2020 21:28
    Reply # 9205296 on 9179655
    David wrote:

    [...] application of heat to the stainless will release the joint. A normal heat gun is usually adequate, you need about 250 to 300 degrees celsius.[...]

    It is epoxy to 6063-T6 aluminum.

    Do I need to worry about messing up the temper of my mast by heating it with a heat gun?

  • 01 Sep 2020 21:26
    Reply # 9205291 on 9199652
    Annie wrote:

    [...]Did you sort out the "hinge"?[...]

    Nope. Not yet. I need to decide how to re-work my first failed attempt at a hinge.
  • 30 Aug 2020 09:39
    Reply # 9199652 on 6872873

    Mine looks huge, too.  But on Speedwell, you don't even notice it, with the mast in and the sail on.  If you sail with junk rig, you have to get used to people making comments about your weird boat.  I've decided to paint my tabernacle aqua.  If you've got it, flaunt it!

    Did you sort out the "hinge"?

       " ...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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