How to find used spars

Discussion in 'Multihulls' started by Skeezix, Nov 19, 2016.

  1. Skeezix
    Joined: Feb 2016
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    Skeezix Junior Member

    Any ideas on how to find used spars by specs? My trimaran plans spec the spars exactly but the specs on Ixx and Iyy or even on ft/lb or extrusion thickness are rarely given in listings. I'll probably want to to buy a used leadmine to scavenge all sorts of parts, and hopefully get much of my money back for lead salvage and engine resale. But I know spars on a multi must be stronger. Seems like I need to look at bigger monos to get my required boom length anyway, and then probably crop the mast. I have been using the RigRite site because it lists a bunch of common boats for each spar, but even that is spotty.

    Here are the specs.
    Mast 32', 5.3"x3.75", 2.4 lb/ft, Ixx>=6.8, Iyy>=2.9
    Boom 12'4", 4.5"x3", 1.7 lb/ft, Ixx>=2.65, Iyy>=1.51
     
  2. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Find the exact extrusion used for the spars and buy similar or exact copies. Dwyer mast is a good place to start and likely will have the same extrusion dies. These would be new, but at least you'd know what you're looking for in the used market. No, I don't know of any databases with used spar dimensions as search parameters.
     
  3. Skeezix
    Joined: Feb 2016
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    Skeezix Junior Member

    Thanks. There is no "exact extrusion used"; all I have is the specs above plus specifics on the hardware and rigging. These are purchased plans from a well-known and respected designer. I guess I can look at some of the boats listed on the RigRite pages because those spar listings have all the specs. Additionally I hope I can also look at comparable boats by checking sailboatdata.com and other sources. I already have started a list of candidates, essentially by looking for monohulls with enough boom. (I wish sailboatdata let you search the database more effectively or would at least share it. But for years he has said he is working on it and has never shared the database.) My search seems to put me right at the 29'-30' loa range, carrying quite a bit more sail than my tri design, so I hope the extrusions should have the beef. I also will do some maths on loading and righting moment and such to see if it looks like I'm in the ballpark. End result is I suppose I'll go driving and measuring boats. Wish I was not hours away from sailable water.
     
  4. UNCIVILIZED
    Joined: Jun 2014
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    UNCIVILIZED DIY Junkyard MadScientist

    Sounds like you're mostly on track. And I gather that you have a copy of Brion Toss's The Rigger's Apprentice, along with other works covering rig scantlings & construction. You can also get rigging catalogs, & look up spar specs on rigging websites. Including the dimensions & profiles of various masts. Keeping in mind that there will be a large number of extrusions that will work, or may have a bit more strength than you need.
     
  5. Richard Woods
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    Richard Woods Woods Designs

  6. Skeezix
    Joined: Feb 2016
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    Location: NE Iowa

    Skeezix Junior Member

    Thanks much.

    While I have been working on learning rigging theory, that book is one I don't have. Thanks for the reference.

    And special thanks Richard for that very helpful article of yours.
     
  7. Corley
    Joined: Oct 2009
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    Corley epoxy coated

    Most spar suppliers can use the data to recommend a section. I ended up finding a secondhand section from a multihull with similar righting moment properties that was destroyed in a storm. It had all the sails too, a real bargain if you can find one like that.
     
  8. Skeezix
    Joined: Feb 2016
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    Skeezix Junior Member

    Yes, I can find plenty of proper sections from spar suppliers easily on their websites. Spars and associated hardware on the Dwyer site added up to $5000. For $5K or less, I can find a mono with all sorts of stuff to reuse. The article Richard Woods linked explains it well. And then sell the two tons of lead for about $1000 and the engine for at least $1000. The question is how to find a mono with the best matching spars. Probably going to need to buy sails as the main will be way more roached and battened, and the jib is fractional.
     
  9. rcnesneg
    Joined: Sep 2013
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    rcnesneg Senior Member

    Is this a rotating wing mast? If so you're going to have a hard time finding a keelboat mast in the right shape. It will also weigh a lot more than a multihull mast. For a 32 foot mast, you might be able to get away with a Tornado mast or something from a big cat. Tornado mast is 29.9 ft, but I know other cats of similar size have longer masts. My F-20 for example has a 31 ft 6 in aluminum mast.
     
  10. Skeezix
    Joined: Feb 2016
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    Skeezix Junior Member

    Thanks for the details! I am paying close attention to mast weights. The plans do call for a "mast base with swivel tabernacle" though the specific mast shape is not defined. I will go with a more wingish profile if I have my druthers, but a mast that I am confident will stay standing and is budget-friendly will be much more important. I can look at an upgrade later when some of these boats have actually seen sailing time. For now I have plan set #6 and only know of one or two builds underway. It is the constant camber DC3 trimaran by John Marples that won the WoodenBoat magazine design challenge in 2011.
     
  11. Skeezix
    Joined: Feb 2016
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    Location: NE Iowa

    Skeezix Junior Member

    mast summary

    As I mentioned, I like the RigRite site because for many spars it lists boats that might have them. This graphic is a summary of candidates I found there. Green circles are "looking good" details. Red ones are less than ideal.

    [​IMG]
     

    Attached Files:


  12. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Used spars come and go in the market. You need to snatch them whenever they are available.
     
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