Light floats

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

  1. bregalad
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    bregalad Senior Member

    I brought up the moisture issue because I thought Bruce has mentioned some previous rot issues in the floats.. maybe on another thread. I've playing catch up on all the Buc -24 threads and there's a lot discussed here and there.

    If Bruce chose to go with foamcore, would it be reasonable to use the existing floats as plugs? I suspect you'd get the new floats off without much problem, but if the old ones were going to be scrapped anyway it wouldn't be the end of the world if you had to cut them up. You could pad out the bow and or stern to make any desired changes With 8mm foam + glass the new floats would end up ~ 11/16" wider overall. A good thing or bad thing?
     
  2. cavalier mk2
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    cavalier mk2 Senior Member

    Not a terrible thing if he made them longer which would be easy enough to do. The boat will change its characteristics with the increase in ama buoyancy and the beams, rig etc....are going to get higher shock loads.
     
  3. redreuben
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    redreuben redreuben

    Bruce,
    If you went 4mm ply then tortured ply shapes could really work for you.
     
  4. oldsailor7
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    oldsailor7 Senior Member

    Yes but how would you get the tortured ply shape that you really wanted.
    EG:- How would you simulate the existing Bucc shape --but in round bilge.

    Foam/glass sandwich would be a piece of cake in this regard.

    WE built three Bucc 33s and three Typhoon Cats in foam/glass and the work was remarkably easy and the eggshell like results astonishingly pleasing. :D
     
  5. redreuben
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    redreuben redreuben

     
  6. oldsailor7
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    oldsailor7 Senior Member

     
  7. bruceb
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    bruceb Senior Member

    Apps and moisture

    Junk 3/8s "home store" ply is apt:p to get saturated when used as floats decks:mad: I have replaced most of it with merenti, well coated and seeming trouble free, but not so light either.
    I have no intention of "scraping" my perfectly good floats, I intend to use them as a small power cat that can be kept out of the weather. !! They are built of 1/4" fir ply and are too heavy for my Buc, but still very useable with an engine. I already have all the pieces ready to go:cool:
    Bregalad, unless a ply boat has been sunk for a long time, weight gain and saturation is not an issue. My boat has spent much of its life in the water, and whenever I have cut into it, it is for the most part, quite dry. Epoxy works! The total volume of wood in a float, for example, is less than 2.5 cubic feet, so the wood would have to be soaking to have more than a few pounds of water total. I don't have a good way of weighing my boat, but I do measure the waterline overhang at the beginning and end of each season. (from the transom and bow knuckle where the water comes to under the boat- about 10-12 inches, each end, for my boat) The change, barely measurable, is less than a couple of inches- probably less than 20 lbs total. B
     
  8. bruceb
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    bruceb Senior Member

    BIG floats

    OS, we know at least one of your old foam/glass 33s is still in good shape, and I wish I could have bought it last spring:cool:
    I am quite aware that increasing the length of the floats is going to increase the loads on everything. I think the beam system is quite robust and shouldn't be an issue, but the float is going to have more stress. By my crude modeling, the areas for several feet in front and behind of the forward crossbeam are the critical points, and will require extra structure. I think Groupama had the same issue, without the best results:rolleyes: I hope I get it right. I still think 4mm ply is easier to design and work with for a one-off, but foam/glass is really desirable from other standpoints. B
     
  9. bruceb
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    bruceb Senior Member

    Deck issues?

    I have 1/4" ply on my decks now and I am sure I can go thinner in the "no step" areas, but the real problem has been the high heels getting stuck in the tramp netting- :D
     
  10. redreuben
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    redreuben redreuben

    Thats not a fault, it's a feature ! :D
     
  11. cavalier mk2
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    cavalier mk2 Senior Member

    Tramps huh, on the Vagabond I've found it easier to remove the hi heels before tangling them in the fish nets.......
     
  12. bruceb
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    bruceb Senior Member

    Changes

    Things have to be done a little differently on multis, but training the crew can be fun;) B
     
  13. cavalier mk2
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    cavalier mk2 Senior Member

    Ladies and the tramps.....A friend helped test ergonomics before the interior remodel, I'm looking forward to reviewing the new layout! With the Bucc interior on the small size I can see how the tramps are important.
     
  14. 2far2drive
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    2far2drive Senior Member

    You guys are a riot! :)

    Bruce, I think the foam idea sounds fantastic. We built light on the 28 but it could have been lighter, foam even more so. But you are correct about the deck thickness, I hardly trust the 6mm on the 28.

    Wow your amas are all fir ply? Must weigh a ton. Would be interesting to get a weight on yours vs the okoume one I just built.
     

  15. bruceb
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    bruceb Senior Member

    Light and tight

    2far, My floats are heavy, one is around 200, the other 220+, I don't really know why the difference, and they are quite dry inside before anyone asks. The 24's floats are about 21' from tip to tip, and I assume the 28's are quite a lot larger-both beam and depth.
    Keep your sheets loose and your tramps tight- and everybody have a good holiday:) B
     
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