Lock Crowther 1962 Kraken 25 trimaran build and rebuild log

Discussion in 'Multihulls' started by Corley, Jun 7, 2011.

  1. oldsailor7
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    oldsailor7 Senior Member

    Corley.
    Since you did your hulls in Triple diagonal lay up and said that if you did it again you would do it in Double diagonal, what thickness did you use for triple and what thickness would you use for double.?
     
  2. Corley
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    Corley epoxy coated

    I don't have the plans in front of me but I would run with Lock's suggestions he gives what appears to be an adequate scantling in the plans. I used them for the triple diagonal on the main hull and double diagonal on the floats and I'm very happy with them. The Paulownia is a bit hard to work without breaking in thicker veneers which was my main reason to go to a triple diagonal on the main hull where the more challenging cold molding is required near the stern. I had to steam some of the paulownia veneers in that area. When I tested some thicker WRC veneers it took the bend around the stern of the hull much better however you suffer a weight penalty with WRC versus Paulownia. The floats are a much easier shape to achieve. The cold molded panels of the float and main hull are surprisingly stiff and yet flexible it's a good material to work with and once the bulkheads and gunwhale strip is in place I think they will be a solid and lightweight hulls.

    The veneers are about 2mm thick so 4mm skin thickness on the floats and 6mm on the main hull. the advantage is you can just have one veneer thickness for the whole project and hence less waste it also fitted better with the thickness of the source material so there were some economies in my case to going that way.
     
  3. oldsailor7
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    oldsailor7 Senior Member

    Thanks Corley. That answers the question I had, because I have a couple of new builders wanting plans and I need to advise them.
    Cheers. Paddy.
     
  4. Corley
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    Corley epoxy coated

    This year at SOMR the trophies were a bit of a homage to the early days of the Trimaran Yacht Club of Victoria. I snaffled one of the spare laser cut stainless TYCV logo's and reckon it will be just the thing for the transom of the K25 :)
     

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  5. Corley
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    Corley epoxy coated

    I'm going to be lifting the main hull of the hull mold shortly after some minor glass work and am wondering if someone is interested in taking the mold to build their own K25. It's probably only a prospect for someone who is reasonably local or can arrange their own transport but it seems a shame to dismantle it without asking the question. It's free of course.
     
  6. Corley
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    Corley epoxy coated

    I've been able to spend some time on the main hull lately, in preparation for lifting the hull off the mold I've filled the rough join section of the cold molding at the keelson with thickened epoxy and covered the join with double bias glass. I might be able to lift the hull and turn it ready for it's internal bulkheads tomorrow if all goes well. I have a plan B if there is any problems lifting the hull from the mold but so far it all looks promising.
     

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  7. oldsailor7
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    oldsailor7 Senior Member

    Lookin' good Corley.
    I think your K25 will turn out to be a lot lighter than the original. :cool:
     
  8. Doug Lord
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    Doug Lord Flight Ready

    Can't wait to see her sailing!
     
  9. Marmoset
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    Marmoset Senior Member

    Wonder how well pencil cedar or even the pencil cedar ply would work on this? The ply I've seen is pretty good quality eucalyptus cored, and see cheap. Comes in 2-3 mm already even. They use it a lot here for drawer bottoms and closet systems. Oh and for some reason I see it a lot in pallets, of which I've seen not only take serious loads but have seen soaked from shipping, and have been impressed they didn't fall apart!

    Barry
     
  10. Corley
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    Corley epoxy coated

    I lifted the hull shell today. It came off the mold with a bit of a fight, I haven't weighed it yet but it's light and it's really quite remarkably stiff for an open shell. I'll get some photos when I'm back at work on Monday.
     
  11. Corley
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    Corley epoxy coated

    I think the easiest way to build the boat would be epoxy/strip plank. I'd probably do it that way if I was to do it again. It's interesting to cold mold but it's a painfully slow process.
     
  12. Marmoset
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    Marmoset Senior Member

    For me probably moot point as paulownia is expensive here, and cedar even redwood is overly abundant. And strip is relatively quick. But at the same time one can say a classic like yours with family history, ya did the right thing in your case, as was and as plan for an heirloom.

    Barry
     
  13. Corley
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    Corley epoxy coated

    An auspicious day for any builder I've turned the hull shell now. I still have a long way to go but it's a nice feeling :).
     

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  14. Doug Lord
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    Doug Lord Flight Ready

    Congratulations, Corley!
     

  15. Marmoset
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    Marmoset Senior Member

    Very cool! And what is that on that shelf foam? I know I'd have been tempted to use some of it!

    Barry
     
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