Adding a Luff Groove to Carbon Mast

Discussion in 'Sailboats' started by BobBill, Apr 30, 2012.

  1. BobBill
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    BobBill Senior Member

    Anyone tried or have information on this...I would like to convert a carbon mast and boom that uses sails with sleeves to use with sails having either a bolt rope luff/foot or slides...either seems better than sleeve.
     
  2. Stumble
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    Stumble Senior Member

    I know a number of boats that use a track that is epoxied onto the mast, and then a layer of CF is applied as a fillet on either side of the track. I can't see why a track would be desirable over a strop for the clew, but it works well for the luff track.
     
  3. JRD
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    JRD Senior Member

    hey BB, whats the boat?

    I have a 6m plastic (pvc?) bolt rope track on my carbon mast. This is glued on with Sikaflex 252 and no other mechanical fixings. There are epoxy products that will be suitable too but if your mast is quite flexible be carefull that the epoxy is able to handle the sheer loads that accompany the deflection. Im not sure I would be so happy with this arrangement if I was using luff slides which would give point loading.
    On the foot, can you make it loose footed and just lash the clew? or use a strop as Stumble has mentioned.
     
  4. BobBill
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    BobBill Senior Member

    JRD, this boat is a Kite, below, unstayed mast...the other, not built, will be Malibu Outrigger, second pic...stub mast 26 foot long yard or somewhat conventional un stayed Bermudan with boom, third pic.

    The Kite original mast has been rebuilt to near orig condition, very good, but requires luff rope sail. I have orig sail, but it is stretched to near useless condition, so decided to use sleeved Force 5 mast and sail rigs as interim plus one Laser Radial sail, but prefer to raise etc conventionally. BTW, these sails are very nice and economical at around 140 each.

    Kite was likely last one built in 73 and MO is 50s boat being updated...a 10:1+ hull/beam ratio, with foam/glass ama and rudder, folding akas, open center cockpit, trampoline...flotation, and more. Not sailing off surfed beach but want to keep it as near simple as original. Way fun and fast proa sailboat.

    MO should come in low 70s Portsmouth, if I do it right. The sail likely to be slides or luff roped...with loose foot, perhaps. All in plan stage before lofting to full size.

    Simple as last pic shows.
     

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  5. Steve Clark
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    Steve Clark Charged Particle

    The easiest thing is to glue a tube to the tube.
    I have cut a slot in a piece of PVC, roughed the hell out of it and bonded it to the back with epoxy. Fillet to increase the bond area. Other than that, there are some plastic luff tracks around that can be glued directly to the tube with epoxy or plexus.
    Composite Engineering has a polycarbonate track that is really nice, I think Forte has track as well.
    SHC
     
  6. BobBill
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    BobBill Senior Member

    Practical Mr. Clark. I wondered about pvc. Will check that and the others you noted. Appreciated much.

    You will smile, but was also considering a wing/Dacron contraption sail, but gave it up as impractical for what I am looking to do with boat. Idea sprung from wish to eliminate sleeve sails...brain never stops.
     
  7. Cheesy
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    Cheesy Senior Member

  8. JRD
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    JRD Senior Member

    Good work Cheesy, thats exactly the track I have on my mast, didn't occur to me to to post the link though.

    So to attatch it, you use the Sika 252, and find a way of keeping the track straight while you apply it. I would consider routing a groove in a plank of 2x4 for the track, then laying the mast on top of it. Mask off on each side otherwise you will spend hours scraping off the silicon that squeezes out.

    Whilst some may question using gorilla snot to stick tracks onto masts, mine has had a good two years of abuse and no sign of any peeling. If your spar is quite flexible there is benefit in having a flexible glue otherwise it may fail by shear.
     
  9. BobBill
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    BobBill Senior Member

    Thanks for the link. I knew about them, but they were down in Oz. Still, might be best to plunge. Have to think on that.

    I think there is now a US distributor, but I sorta think like Mr. Clark and do stuff with what I can find. I may end up with the glue on luff groove...being able to fix fast if needed is a big factor...as opposed to waiting for parts etc.


    For what it is worth. The wee boat above has the wood mast with luff groove, the sail is blown out - not surprising, since it was made in 73 - so I am using sleeved rigs temporarily and some carbon surfer spars.


    The need for a luff groove extends to the Malibu Outrigger I plan to build. Sleeves are impractical for anything but smaller beach boats, it seems to me.
     
  10. Cheesy
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    Cheesy Senior Member

    Careful there New Zealand and Australia are not the same place.....
     
  11. gggGuest
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    gggGuest ...

    Look for manufacturers/suppliers of plastic track for awnings. Used on caracans and the like. It may even be the same stuff.
     
  12. BobBill
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    BobBill Senior Member

    Yes, I shall do that, never occurred to me...appreciate it gggGuest.


    Cheesy, I will be more careful. I thought the outfit was in Queensland...duh on me.
     
  13. waikikin
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    waikikin Senior Member

    That "Malibu outrigger" is cool, gotta google em now..........
     
  14. BobBill
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    BobBill Senior Member

    Malibu Outrigger

    I have been looking at various catamaran and even mono sailboat designs, and none have been as simple, fast or low cost as this particular boat. It was "the" boat in Malibu in the 50s and 60s, and was eclipsed by glass productions boats. Now, one can build and update as needed and still look for speed.'


    It is, essentially, a tacking proa, but with its mast/sail on a main hull, it can be much simpler than a typical cat and as fast...


    What hooked me, besides being unique, is its simplicity, bow, stern, and three internal stations. Outrigger could really be anything, and extend out to 14 feet, unfolded...


    Using moderate marine ply, looking at about $2K for wood, maybe that for sail, but options available and trailer...and labor about 300 hours.


    Carry cases of beer, etc and still cruise like a dream.


    By the way, I have concluded one could use a sleeved sail, with loose foot, if the center section (where halyard blocks attach) is managed.
     

  15. BobBill
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    BobBill Senior Member

    I know this is older thread, but too often these things are left hanging...

    As Steve Clark noted, I pursued adding a luff groove to the carbon surfer masts...only way I figure to fly a sail from the gaff, due to the gaff hardware, and still be able to hoist and strike the sail quickly...

    I located carbon fasteners or screws and carbon tube with ID that will accommodate bolt rope...

    Figure to epoxy short tubes to spar sections as well as screws at each end, which should not hinder flex needed. (After I add carbon sock to the spar...to stiffen as I did with extra mast for Kite Dinghy.)
     
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