forcing trees and bamboo to grow into boat-framing component shapes?

Discussion in 'Boat Design' started by Squidly-Diddly, Jun 22, 2010.

  1. bearflag
    Joined: May 2010
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    Location: Thousand Oaks, California

    bearflag Inventor/Fabricator

    Development of bamboo-based polymer composites and their mechanical properties

    http://www.sciencedirect.com/scienc...serid=10&md5=5cdbb14c88da114e4319008c9890889a

    Development of bamboo-based polymer composites and their mechanical properties

    Kazuya Okubo, a, , Toru Fujiia and Yuzo Yamamotoa
    a Department of Mechanical Engineering and Systems, Room YM304, Doshisha University, Kyo-tanabe 610-0321, Japan

    Available online 5 November 2003.
    Abstract
    This paper presents the development of composites for ecological purposes (Eco-composites) using bamboo fibers and their basic mechanical properties. The steam explosion technique was applied to extract bamboo fibers from raw bamboo trees. The experimental results showed that the bamboo fibers (bundles) had a sufficient specific strength, which is equivalent to that of conventional glass fibers. The tensile strength and modulus of PP based composites using steam-exploded fibers increased about 15 and 30%, respectively, due to well impregnation and the reduction of the number of voids, compared to the composite using fibers that are mechanically extracted. The steam explosion technique is an effective method to extract bamboo fibers for reinforcing thermoplastics.
     
  2. uncookedlentil
    Joined: May 2008
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    uncookedlentil Junior Member

    yes, the correct approach of fairing compound is the key here, wood flour or micro balloons squeegeed into the woven mat to fill and wet out a layer of fabric on the green filled core. vacuum bagging to a smooth surface is easy and a time saver. constant camber, cylinder molding will prove to be viable approaches
     
  3. BATAAN
    Joined: Apr 2010
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    BATAAN Senior Member

    Traditional shipbuilding uses "compass timber" wherever possible for futtocks, stems etc that benefit from curved material. The shipwrights cut the wood in the winter when the sap was down and the snow made it easier to skid the material out. The yard master went into the woods in the fall to select and mark material. His practiced eye and a few molds told when a curve was close enough for a particular job. BERTIE is framed with Port Orford Cedar, much of it compass timber, from weathered curved stumps in the Oregon forests cut from steep hillsides.
     

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  4. Squidly-Diddly
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    Squidly-Diddly Senior Member

    BATAAN-that is the term I was looking for!

    www.google.com/imgres?imgurl=http:/...s=org.mozilla:en-US:official&gbv=2&tbs=isch:1

    Not sure why they call it "compass".

    Still looking for any intentional deforming/growing of trees into pre-determined shapes.

    Being as many boat shapes have been around for ages I'd think it would make sense especially as the investment of time and energy would be quite low, except the actual waiting for the tree to grow. After all, they are certainly planting lots of trees they aren't going to harvest for 30 or more years.
     
  5. Squidly-Diddly
    Joined: Sep 2007
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    Location: SF bay

    Squidly-Diddly Senior Member

    BATAAN-that is the term I was looking for!

    http://www.islandtrees.com/IMAGES/b...s=org.mozilla:en-US:official&gbv=2&tbs=isch:1

    Not sure why they call it "compass".

    Still looking for any intentional deforming/growing of trees into pre-determined shapes.

    Being as many boat shapes have been around for ages I'd think it would make sense especially as the investment of time and energy would be quite low, except the actual waiting for the tree to grow. After all, they are certainly planting lots of trees they aren't going to harvest for 30 or more years.
     
  6. bearflag
    Joined: May 2010
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    Location: Thousand Oaks, California

    bearflag Inventor/Fabricator

    http://www.killerplants.com/plants-that-changed-history/20050215.asp

    The grain along a curved branch or trunk gave the shipwrights special pieces of lumber called compass timbers. The timbers were so named since compass meant circle and these timbers were shaped to a curve or arc of a circle.
     
  7. BATAAN
    Joined: Apr 2010
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    BATAAN Senior Member

    Compass timber refers I believe (wild conjecture) to the use of the drawing compasses in layout, especially in pre-nineteenth century work. Before the widespread use of models and drawings, shipbuilding in some practices was reduced to a set of rules and proportions, combined with arcs of circles, such as the replica MAYFLOWER built in the 1950s. I was once Captain of the 1992 Columbus replica NINA, built in Brazil using authentic fifteenth century design and building methods (compasses and a logarithm rule), and she was most hydrodynamic and slippery, leaving little wake under power or sail (off the wind). Her rig, on the other hand, would have been modern in Roman times, and was a constant learning experience. Anyway, back to subject, check out Chapelle's American Small Sailing Craft and other out-of-print works for great anecdotal detail on the subject of crooks in framing.
    In general, a "real" boatbuilder, that is one who has to put bread on the table with the job, must get his vessel completed in a very short time. This is economic imperative, as it's costing him money until the customer pays and takes it away. In the Caribbean it was common to tie "horseflesh" (hardwood framing material whose proper name I do not know) branches into more convenient shapes for future harvest. Also the Bahamas I think did the same. But these are places with a very strong wooden cheap workboat tradition among very poor watermen who respect each others' material. It was tradition to harvest the crooks your grandfather tied I think. Working on Pirates 3 on Grand Bahama in 2005-6 I was tasked with managing a very large fleet of various disintegrating historic small boats and got intimately acquainted with their construction over a painful few weeks of 14-hour night shoots. One of these craft was an old working conch skiff with all grown horseflesh crook frames, fastened to crook floor timbers, tapered both ways from floor to head. Stem was the same, but a different wood I didn't recognize. At least 75 years old and in quite good condition except for some rotten planking. There's no waiting in the movie world so 3 of us virtually rebuilt 12 local skiffs and dinghies (very 18th century in model) and turned them over to the painters in a week. The next night they were on camera. Sorry I couldn't find a photo of the interior of that boat, but here's the outside, as well as others.
     

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  8. Tiny Turnip
    Joined: Mar 2008
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    Tiny Turnip Senior Member

    A brief reference to deliberately growing curved timbers for ship building here:

    http://www.navyandmarine.org/ondeck/1800shipconstruction.htm

     
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