Light floats

Discussion in 'Multihulls' started by bruceb, Dec 2, 2012.

  1. redreuben
    Joined: Jan 2009
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    redreuben redreuben

    So Bruce.......whats the plan ?
     
  2. bruceb
    Joined: Nov 2008
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    bruceb Senior Member

    4mm floats

    I have decided to build with 4mm ply, and I will be receiving the 4mm ply later this month. I will start building bulkheads next week. The floats will be about 23' 6" overall, about a 2' increase (10%), but the same width as stock. I have decided to build them with sort of a hybrid construction method using external frames like some of the stitch & glue boats use while pre-attaching some of the internal framing as on the original plans. By building in a jig, I can be assured of accurate and identical hulls, add carbon fabric inside where necessary, and keep internal framing to a minimum. I will add two extra partial bulkheads and some extra framing/bracing in the high compression and load areas, also much easier to do in the jig. The external frame set only adds about $50 US total to the cost, and I think will save time. I have built small ply power boats the same way, and it is fast and easy. I will photograph the build process.
    I am using 4mm merenti on the outside skins and bottom, and okume on the inside (towards the main hull) and the decks.
    The float transoms will be partially vertical and strengthened with carbon rudder eyes added. I probably won't get the rudders installed anytime soon, but I think float rudders are a real improvement and I want to allow for them.
    I am confident I can get the finished weight below 160 lbs, will try for under 140 lbs, and would really be happy with less:cool:,
    B
     
  3. oldsailor7
    Joined: May 2008
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    oldsailor7 Senior Member

    Sounds like a plan Bruce.
    What epoxy are you going to use. There are a lot of good boat building epoxies available now which are much less toxic than WEST epoxy. I hear MAS is a good one. The most important quality, apart from good saturation ability, is that it is thixatropic enough that it wont sag as it heats up on vertical surfaces during cure. Also it has to be 100% solids, ie:- the thinner or dilutent is not an evaporative solvent. When a solvent evaporates it leaves thousands of micropores in the coating, which enables the entry of water vapor, which of course wrecks the whole theory of epoxy encapsulation. :eek:
     
  4. bruceb
    Joined: Nov 2008
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    bruceb Senior Member

    epoxy

    OS, I usually use Raka epoxy, a smaller "local" blender based in Florida with very competitive prices. They are a supplier to the southern boat building and repair industry, and of course, home boat builders. I have had good results with their various products, and I am used to working with their system. They are also quick to help over the phone or online. They have hardeners that are useable in our summer time temps, a real plus, but their epoxy doesn't seem to have as long a shelf life as other suppliers. (The epoxy in the pumps tends to crystallize) I use enough so my supply is usually fresh.
    They have different types that can be combined for the best results, but on my floats, I will just rotate them so the surface I am working on is almost horizontal, and I use a lot of peel ply for pre-finishing. I am lazy! ;)
    I can't comment on allergies, I have always used gloves and protective clothing and I have never had any issues. I try to sand as little as possible, and I have respirators and a good dust control system for when I have to.
    B
     
  5. oldsailor7
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    oldsailor7 Senior Member

    Good OnYa Bruce.
    Yes I have heard Raka is a good epoxy too. It's a shame that Bote-Cote epoxy is no longer available in the USA.
    The guy who bought the franchise for it was a poor businessman and when his marine business went down the tubes Bote-Cote went with it.
    However it is still widely available from Boatcraft Pacific, in Australia.
     
  6. bruceb
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    bruceb Senior Member

    epoxy choices

    OS, I wish Bote-Cote was still available here also, my boat is a good testament to its suitability. I wish I remembered more of my high school chemistry, I think it would help understand the differences in the epoxy formulations. I always wonder what the different suppliers are adding or leaving out. I sense quite a bit of "hype". :( B
     
  7. redreuben
    Joined: Jan 2009
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    redreuben redreuben

    Bruce,
    does this move to long floats mean no lifting foils ?

    Speaking of which were they used in conjunction with the main foil or instead off ?
     

  8. bruceb
    Joined: Nov 2008
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    Location: atlanta,ga

    bruceb Senior Member

    foils

    I am planing to use foils, and will use a slightly smaller trunk than my first ones. I think the foils are really important, but I want the larger floats too. Coming out of tacks and in gusts, the floats are doing the work. B
     
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