rig tuning bow beam shrouds

Discussion in 'Multihulls' started by Charly, Dec 31, 2014.

  1. Charlyipad
    Joined: May 2014
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    Charlyipad Senior Member

    Argh. I am getting an ulcer here.

    First, thanks to you all for the replies. this is very helpful stuff.

    Ok the original plans called for 3/4 inch aluminum plate welded to the striker and 3/4 alum Chainplates. the Chainplates are embedded into the ends of the plywood bow beam. The gull striker bolts to the top ofthebow beam"


    I have always liked the idea of a soft connection, and would like to try it maybe.Wouldyou still need the insert with a soft shackle??
     
  2. Charlyipad
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    Charlyipad Senior Member

    Here is a photo of the striker from the build thread.

    http://www.boatdesign.net/forums/at...d1404740939-kurt-hughes-daycharter-36-005.jpg

    The bushings are just cut off pieces of 316 ss tube 3/4od x1/2 I'd.

    The fit on some of them was loose enough that they wouldn't stay put on their own. On a couple of them I had to press them in place with a pair of channelocks. I coated the all with 5200 to try and get some insulation.
     
  3. Charlyipad
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    Charlyipad Senior Member

    http://www.boatdesign.net/forums/at...99466819-kurt-hughes-daycharter-36-007-2-.jpg

    Ok here is a pic of the beam end, with a mock up plywood piece where the alum Chainplate will go, before it is all fastened, faired and glassed up six ways to Sunday.

    I have been thinking ll along that it would be. Simple matter of putting a shackle pin through the holes in the plates and rig it all up from there. not so simple:p
     
  4. groper
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    groper Senior Member

    Nup, you wouldn't need the ss bush with a soft shackle. You need a radius for it though. Sharp corners ruin the strength of them. A bit of smoothing with a Dremel might do it, otherwise you may be able to pass an open ended thimble though the alum plate where the bush was an then splice the softie around that.

    We have thimbles directly connecting our turnbuckles to Dynex cap shrouds, diamonds and gull striker ropes... We also have loops cinched to ss rings, t-ball fittings and what not also. We've also used softies to connect all our halyards, boom vang preventer, main sheet, main out haul, even our primary anchor to the 3/8 chain... Lifelines are also spectra, but these need to be redone properly. Stainless is so heavy, and so yesterday :p it's also more expensive

    If all this seems a bit much, why not a stainless shackle with a 1/2in pin through your existing bush?
     
  5. Charlyipad
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    Charlyipad Senior Member

    I could do that, would need to figure out a way to get a good connection from there to the toggle.. Toggle clevis would then bear on the rounded top of the shackle (don't know what you call it), and that would not be good as I understand it.
    use two shackles with the pin of the second going through the toggle jaws?
    seems like a lot of extra connections
    The bridle lengthis fairly critical. Has to be factory swaged I need to be sure of what I am going to do before having one made up to length
     
  6. Charlyipad
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    Charlyipad Senior Member

    Guys this discussion has been helpful to me. I think the path of least resistance at this point is to remove the bushings and upsize them to 5/8 pin and be done with it.

    Re stainless vs bronze bushings I understand the nobility scale etc,butIthink somewhere someone said don't use bronze as it will wear faster. Any other Opinions? And which alloy bronze would be best in this case. Aluminum plates are 6061.

    Groper,I definitely want to come out of the stone age:) Iam sold on synthetic lifelines . I will have some questions I am sure whenI get to that one. Thanks
     
  7. RHough
    Joined: Nov 2005
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    Location: BC Summers / Nayarit Winters

    RHough Retro Dude

    There should be no movement in that bit of rigging ... it cannot wear in that sense. I've seen the result of SS bushing and pins in Aluminum chainplates. They corrode into junk. By the time you manage to get the pins out the chainplate is damaged and a bushing or new chainplate is required. If you take the rig apart for an annual inspection and re-coat all the pins with corrosion inhibitor, you can get away with it ... nobody does that unless they dry store their boat with the mast out every winter. In moderate and tropic climates rigs get left in boats until something fails ... very few people do even a 5 year rig out inspection. At 5-15 years the ss rigging bits might as well be welded to the chainplates.

    No matter what bushing material you choose you need to prevent it moving in the tang. If it can shift to one side it will and reduce the effective bearing area on the pin. This leads to the hole in the tang getting distorted and eventual failure.

    Not trying to scare or confuse you at all ... just have seen many poorly thought out rigs (even from good manufacturers). The devil is in the details as you are finding out on what looks like a very simple part of the boat.
     
  8. groper
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    groper Senior Member

    I will get some photos of our rigging when I get a chance... But yes, putting the shackle to the toggle is what I had in mind. I don't see a problem doing that however not as good as replacing the bush and reducing the number of components.

    If you havnt bought the wires yet, look into the Dynex Dux... All you need to be able to do is a Brummell splice using a fid. it really is child's play and takes about 10mins each one. The turnbuckle toggle goes directly to the ss splice thimble to dead end it, which is a pin to round type connection... Holds our entire rig up at every stayed point... No need for swaging wires and less hardware in total. When it's time to replace it, you get visual cues unlike stainless where you can't often see. Then simply splice on a new peice of rope yourself and your good to go again, it's very diy friendly. If you havnt read up on it, the colligo marine website has a lot of good info on synthetic standing rigging...
     
  9. Charly
    Joined: Dec 2009
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    Charly Senior Member

    Thanks groper, would love to see the pics. Ive already pulled the trigger on the bridle wires but will try dynex or similar on the lifelines.

    on your stanchions what do you do just put a clove hitch or something on each one and tighten as you go?

    sorry for the thread drift
     

  10. groper
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    groper Senior Member

    That's the way it done at the moment, but it's no good. I'm going to drill a hole in each stanchion and pass it through, then simply lash the ends to tighten them up. No hardware required what so ever, just buy the rope cheap as on ebay and go for it :) look up dyneema winch rope on ebay for best prices... the lifelines don't have to be dux -which is the very low creep version of dyneema. ..
     
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