bamboo planks

Forgot to add that we will be adjusting “a notch” (cut to depth and siced/prayed out with a machete( “itak”)) twice every 10 inches on each outer strip with slightly varying angles and depth. This will leave the the outer surface fair despite the non uniform thickness of each strip(9/16” to 3/4” thick). The width of each strip is immaterial as long as the edges are relatively straight. The strips do not go though a saw or planer. They are just skinned, then split and then cleaned up. About an hours labor for each large cane. At 60% usable for use in the center hull, this will require approximately 1000 canes and and 1000 hours and $2000 say $2500because I just can’t haggle over basically pennies(at least not with the required straight face) for the complete lumber bill of the yacht- 30 tons. Overbuild is the simple solution. With a 100 tons of payload you can spare a dozen or so. Its intended “cargo” would be bamboo canes anyways. These can be lashed into decking/cabins/CEO’s beams/floats/masts... and removed and sold later as “used boat parts’ actually the “overbuild” will come out ahead of the game as I’m not going to stuff 500 pax into the thing, maybe only six. 165LOA 130
LWL 18 ft beam at deck level (waterline will “fall into place”). Not sure BOA yet. Maybe 120-170. Got to see first what rig will look like. I’d prefer it to adjust to level heel just like a windsurfer and maybe a bit of water ballast. Not too important, so long as it averages 10 knots I’m happy. A 25hsp diesel will push it 5-6 knots.

 

As far as “large” timbers with “tight” tolerances, one way to do this would be to manufacture a longitudinally biased plywood. There are bamboo species large enough to have 18-20inch long internodes. Use this completely straight grained material to assemble say 6”x18” by ANY laength. Laminate (skin removed, split (6 pieces) , inside shaved down to remove fungus, difference in thickness minimal and and made nonexistent by flipping every other stick) all the short strips at +/- 15-20 degrees edgewise, say 3”(curved) x whatever width inside of a couple pieces of c channel fixed 7” apart. Clamping pressure comes from a vise on one end of the length pulling against itself(the c channels) and other end is just capped. Remove from jig after initial cure and make five more. Machine plane too and bottom and saw of a 1/2 inch or so on each of the jagged sides then surface plane both of those edges. Flip three of the planks and laminate all six together in a different jig. Now you have a 6x18 say 50 feet long 700lb structural grade composite beam. What is that worth? Certainly more than $8 plus glue $30(commercial pricing)? More like $1000 is what you have created with the bamboo. I think I could assemble 4 of those per day. I used to toss 50,000 lbs of frozen fish into boxes every day. No dimensional unevenness, no broken fibers, 1000 fold increase in cross grain strength at a cost of maybe 8% of tension parallel to grain. I would bet a little CCA mixed ito the glue would take Carr of the “rot”. And if you used the commercial plywood glue the heat woul sterilize the bamboo to start with. (Got to build an oven but glue is cheaper). Our trimaran will utilize 6 of these beams. Whole bamboo will be lashed to these top and bottom outward to the outriggers(floats).

 

These forums would benefit from more science and research and fewer unsubstantiated opinions. In the first few pages I found these opinions about bamboo:

“That was the nice reply, now comes the truth:
hands off! It is just not possible to use Bamboo in modern boatbuilding methods! “
“Definitely not! Neither cheap, nor eco friendly! And surely not sensible.”
“I do´nt like to contradict you, but please would you tell me a single one advantage a Bamboo veneer could have over a quality wooden veneer? Just one!”
“Simply, whatever its qualities, bamboo is not a material for boats.”
“You're making some incorrect assumptions there Dop Bar. Bamboo has been looked at by several companies and industry professionals.”

I am planning to build a high performance sailing canoe and I am evaluating foam sandwich wood veneer materials. To my surprise the mechanical properties of bamboo put it at the top of the list despite its heavier weight. In addition bamboo veneers are a now becoming a commonly used material in stand-up paddleboards and surfboards. Bamboo may not be appropriate for large boats kept in the water, but it seems to be finding a place in surfboards that could extend to canoes and other small boats kept out of the water. I had considered using 1.5mm (0.060") thick mahogany ply but the shipping costs of large sheets to Colorado doubles the price. On the other hand veneers can be shipped economically in a rolled tube to my location making 0.8mm (0.035") 2-ply bamboo veneer cheaper and lighter than 1.5mm (0.060") mahogany marine ply. Epoxy carbon cloth appears equally cheap and a bit higher performance, but requires considerable additional sanding at exterior hull surfaces when using male molds. In response to the original poster, it may be possible to cut 2-ply bamboo veneer into strips for use in strip planking with epoxy carbon overlays, though admittedly not as efficient as a lighter wood such as cedar or foam strips. As a counterpoint to the many negative opionions reguarding bamboo use in boats, I am listing bamboo surfboard manufacterers and also the mechanical properties of bamboo compared to African mahogany (my second choice). There are several varieties of bamboo with widely varying properties. For comparison purposes. I have taken the average of the high and low numbers tested. In summary, the average bamboo species compared to African mahogany is 17% denser, has 34% more rupture strength, has 41% greater hardness, has 79% greater stiffness and has 58% greater crush strength. High strength bamboo varieties are significantly better. Testing numbers from manufactured veneers would be ideal, but they appear unavailable from my cursory search. Of course bamboo is much more susceptible to rot than mahogany and so must be well sealed and stored out of the water.

1. African Mahogany Specific Gravity: 0.52
2. African Mahogany Rupture: 31,190 lb/in2 (91.0 Mpa)
3. African Mahogany Janka Hardness 1070 lb (4760 N)
4. African Mahogany Modulus 1,537,000 lbf/in2 (10.60 GPa)
5. African Mahogany Crush 7,100 lbf/in2 (49.0 MPa)

1. Bamboo Specific Gravity Average: 0.61
2. Bamboo Rupture Average: 17,735 1b/in2 (122.3 Mpa)
3. Janka Hardness Average: 1510 lb (6740 N)
4. Bamboo Modulus Average: 2,755,000 lbf/in2 (19.00 GPa)
5. Bamboo Crush Strength Average: 11,240 lb/in2 (77.0 MPa)

Source: The Wood Database https://www.wood-database.com

Standuppaddleboardsreview.com. December 4, 2018
These brands are our top nine list of the most popular and affordable bamboo paddle boards:
1. Long Island Boards, The Montauk SUP
2. Surftech Bamboo Paddleboard Generator TEKefx
3. Wappa Nova SUP
4. Kanghua All Around Performance Stand Up Paddle Board Bamboo
5. Levitate Bamboo Paddleboard
6. Crazzie Real Bamboo SUP
7. Tuga Tiff Bamboo Paddle Board
8. Boardworks Joyride Flow 9’11” Yoga Bamboo SUP
9. Kona All Over Wood Veneer SUP

Google Search: Bamboo Surfboard Companies
1. Liquid Shredder
2. Bamboosurfboards.com.au
3. www.surfdust.com/surfboards/

Comments invited!