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

[bearflag]

http://www.sciencedirect.com/science...19008c9890889a

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.

[uncookedlentil]

Originally Posted by eponodyne

So is there a variant that grows to only a small diameter in long lengths? Weaving that and covering with 6-ounce hemp is certainly something I'd be willing to try...

,,And I would love to see ya try, but I can't claim credit, this one came from Apex 1 in a serendipitous moment of pure brilliance, but I've got an experience edge that could make this project a resounding success.

make up a2x2 panel or two using fabric inside and out and a woven core of flat split bamboo. Look up flyrod making on utube, simple and NO sawdust to boot


For that matter, I'm pretty sure you can get fabric that's 80% plus bamboo content and up. I know I've got some socks made out of 90% bamboo, the rest polyester, and they're both soft and strong. I'd think a few layers of this would handle compound curves nicely. I've got to believe you'd need a heavy hand with the fairing compound, I can't see this stuff sanding well at all.

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

[BATAAN]

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.

[Squidly-Diddly]

http://www.google.com/imgres?imgurl=...26tbs%3Disch: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.

[Squidly-Diddly]

http://www.islandtrees.com/IMAGES/bo...26tbs%3Disch: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.

[bearflag]

Originally Posted by Squidly-Diddly

Not sure why they call it "compass".

http://www.killerplants.com/plants-t...y/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.

[BATAAN]

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.

[Tiny Turnip]

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

http://www.navyandmarine.org/ondeck/...nstruction.htm

Some brief comment should be made here regarding the material from which the ships were made, the preferences held by some shipwrights, how it was cut and formed, and it's bulk measurement and quality. To the extent possible natural bends in wood were used for "knees" and angle-like ship's timbers. The preference in English shipyards for oak and the preference for natural strength over that of "fasteded" timbers led to this usage. Oaks from the areas of Northern Europe were fine for the development of long straight planking, but the gnarled English "Hedgerow" Oak was the best for the natural curved timbers used to strengthen the ship internally. Trees were even deliberately bent in certain ways so as to " grow" a needed set of curved timbers. These curved timbers were known as "compass" timbers.