bamboo strip planking for structural use

Sounds good to me, don't know if you will find published data, you may need to run your own tests.

Do you have a good source of bamboo?

Plenty of native boats use bamboo for outriggers?

It is used in bow making so must be pretty goos in compression and tension, ideal for designing a structure with some flexibility, which is probably better than trying for rigidity....Bend with wind grashopper.

Good luck, it sounds a fun project.

Del

I hope responses aren't limited to those of feline origins, exclusively.

Taiwan and similar build incredulous scaffolding structures for work on high-rise projects. Wish I had a link to direct you to, the point is I agree with El Gato Del, flexibility over rigidity.

ie; wooden roller coasters

flex and lightness is the key for a cat, my major concern is that it would not behave the same way as okoume.I heard it is the strongest material on earth for it s weight. Graphite and carbon are brittle. got to run . later

Dear Friend

There is a POSSIBLITY that the BAMBOO can be trated with LATICESS with flexibility (there are a lot available) by dipping henece the FLEXURAL & OVERALL STREGTH is increased but still I doubt that as the BAMBOO is BIODEGRADABLE hence it is prone to FUNGUS attack although due to treatmnet this POSSIBILITY is reduced or even eliminated for PROPER synthetic LATEX/DISPERSION this will govern by various factors it has to be TRIED out if interested more please contact TEL No.91-20-24532278 MAIL:anantr1@gmail.com

REGARDS

RANADE

Del del Gato??

Del del gato.

Algo así parece haber pensado Colin Bruce. ¿Cómo acercar la Física al lector común? Su respuesta es "La paradoja de Einstein y otros misterios de la ciencia resueltos por Sherlock Holmes" (en realidad, el título original no menciona La paradoja de Einstein sino El extraño caso del del gato de la señora Hudson) con traducción de Eduardo Margaretto Khormann. Edita la editorial Granica. Barcelona, 2001. 303 Págs

http://clio.blogia.com/2004/021301-profesor-holmes.php

Are you hollerin at me?

What a rush! A roller coaster built on a bamboo forrest. Just think about the sway factor!

I admire your initiative right in one of the coldest area of this planet where obviously bamboo might require hot house to grow !

FYI bamboos make excellent piling for permanent constructions and is used regulalrly in Indonesia. In Papua New-Guinea I have seen it used in woven form (the shoots are hammered into a flat and woven into mats ). This can be used in construction instead of steel in concrete. It works. Bamboo does not rot it is very resistent and equates hard wood piling in sea-water for long term resistance.

Wish you luck and if you need specific info will gladly oblige, but if you want good quality bamboo go to China,

LABOR

Not only does bamboo grow readily in Canada, but once established, it is a bugger to get rid of, sort of like people with ridiculous misconceptions "aboot" Canada.

It's a bugger to get rid of anywhere it gets established. Many nursery ask all kinds of questions before selling it to a customer. Also, they make special nets to put in the ground before planting to keep it from spreading.

It snows in China. It snows where the giant panda roam, and they eat bamboo. I can't see Canada being any problem. Furthermore, bamboo is used so much in Asia as a material, I can't believe no one has the specs or has written a book. This would be like the US using steel without any knowledge of what type was good for what.

The knowledge has to be out there - tensile strength, species, and so on.

One odd thing about bamboo is the "Bamboo Clock." Each species of bamboo lives for only a specific number of years, when the time hits "zero," that species of bamboo dies no matter how old the plant is or where it's located in the world. In the past, these universal die-offs caused whole economies to crash. Pick a bamboo that has enough time left to get your project done.

Bamboo's fibers run in only one direction. With that in mind it sould work fine in composit plastic construction.

Fair sea's & following winds

Gordon

And don't sit on a splinter!

Sounds like a good idea to me and if encased in epoxy, you should get no problems with regard to biological degradation......etc..

Send us some pictures if you manage to get the project off the ground (onto the water!)

Bamboo is sold in the US as flooring. It's beautiful! Check with high end flooring shops.

Bob

I'd ask Pandas. I didn't bother reading up on it, but woodn't it be prone to nasty brittle failure ? In other words, all seems fine as it flexes and takes the strain, then all of a sudden kaboom. No tensile elasticity to warn you of disaster. I've no idea what Chinese boats are made of, but that might be a good place to start looking for design hints.

Nah . . . Ain't you ever heard of a cane pole for fishing? I've used one for years, and I've broken a few, but it's not very brittle. Some of the finest fly rods are made from bamboo.

But when you catch a super-heavy Oz toad, doesn't your pole just bend a lot then eventually snap all of a sudden ? I had a frog once and mine damn near fell apart.

They don't snap, they splinter, much like fiberglass poles. This is why bamboo poles are wrapped with thread at the skinny end, to hold the fibers together and prevent it.

Here is a link with lots of data on bamboo. I'm not sure about the description of 'splinter' as a failure mode, but such terms get used differently by different fields of Engineering etc. Generally I'd stick with compressive/tensile/shear but plenty of other words get used in relation to progressive failure (necking, creep, spalling and so on).

For a bit of fun, consider this: "There is no such thing as compressive failure in rock." Then look at how tensile stress can be deduced by Brazilian disc method. Darn - can't find a decent link. In short, a disc shape is compressed across it's diameter. The thing splits in tension along the diameter. The case is slightly more complicated because of edge effects producing some degree of shearing failure. My point is that it's all in the words, so 'snap' and 'splinter' are probably being applied by us both to mean the same thing.

"There is no such thing as compressive failure in rock."

Is this teaser yours or did you find it at a boot fair...?

If this is true ....then

There is no such thing as compressive failure in blancmange either!

It sounds like a game of semantics to me....someone once said to me

'there is no such thing as pulling, if you analyse it it is always pushing', sounds like the same sort of statement.

Or is this just Del mouthing off 'cos he has the sniffles?.....ahhhh, bless.

Hey, I got sniffles too ! <Hope it wasn't our snog behind the bike shed.>

"There is no such thing as compressive failure in rock."

It's more like a mischievous question. Jack up a nice bit of rock with triaxial pressure and watch the gauge shoot way up. Ultimately tiny imbalance of force is going to crumble it by shearing crystal planes/ asperities etc. Even if you uniaxially squash a cylinder it's not exactly 'compressive' failure. Yes, I is playing semantics. The disc thing just makes the point nicely- It's an indirect method of measuring tensile strength (only compression is applied). Compressive strength obviously has useful meaning, but I was feeling a moment of seriousness coming on. OMG ! I should have stuck to analysing the meaning of splinter. Much more fun.

Yes but what about the blancmange testing..?

Ladies in bikinis ?

No good wriggling out of this...

PS Have a peek at the RADAR thread...dunno if it's your thing....but it may raise a laugh!

The Blancmange problem may take some time. Damn the rainy weather. Perhaps Sky will have some useful info later tonight. mmmm

I don't fink I've seen the RADAR thing yet, will go check........

Aaaarhhh...

The evil linkmeister strikes again...I'm mortally wounded Kris!

My powers are waning...you know I'm alergic to maths.....

I'm alergic too, but I can still muse on whether the graphs were too much or too little fractifilated. Some kind of time function is needed. Looking at the screen upside down doesn't help. I will check the 'Discovery' channel.

Well well well, Del. So we've discovered your weakness HA HA HA HA . So where is your Splinter now Kris?

I have solved the problem HAHAHAHAHAHA!

http://en.wikipedia.org/wiki/Blancmange

As said earlier, I may investigate woody stuff later tonight. It's just struck me that I don't recall ever seeing a white blancmange. Jelly is far more interesting because of its transparency (and has the advantage of not sounding French). Not that I really like either, I reckon it's all like nasty Clowns that get foisted upon kids. Given the choice I like that Tiramisu stuff.

I hope you guys know that a young EIT from Texas sure has a hard time keepin up with you Brits inside humor - does it show?

Blame Del, Blame Del ! I always do and it works a treat. I loose the plot all the time.

...it will keep your grey matter from congealing!!!!

I believe that Blancmange was originally white, probably several centuries ago (I have not yet looked it up on Wikipedia!), just going by its name alone, but of course we have added extra flavours over the last century or so to make it more attractive.....

....though I have to admit that I haven't eaten it in probably 30 years, if not more!

(I'm still trying to figure out how mange-tout comes into it)

....as recently as 30! Pretty soon it'll be about the only thing I can eat.

There probably is a terminology for what happens when bamboo fails that I'm not aware of, but I'm pretty sure it isn't "snap", because that is not what happens. More like a crackle at the (gradual) point of failure. Try breaking a length of bamboo into two separate pieces, it is very difficult to do. You flex it back and forth and it splinters (if you have a better word, I'm open to suggestion), but it is reluctant to let go, with fibers remaining stubbornly attached between the two pieces. As previously stated, much like what happens with a fiberglass rod (sometimes you just gotta grab stuff and break it to better understand it, I call it the Munky Hands-On Method).

Splinter is fine by me (though I'm gonna keep my snap for now !). There is a good general term for such types of material failure : " Oh *<^* !"

Asian construction workers, painters, etc also use bamboo for scaffolding up to considerable heights! One caution: Be sure you know who the bamboo supplier is, or test a piece before buying. Bamboo is also used as a very attractive "hardwood" flooring wood, but the bamboo is being harvested too young in many cases, and it is quite soft. When used for flooring, young bamboo will dent from women's high heels. Depending on your design, you might want to coat the bamboo with a good, hydrolytically stable coating, such as a polycarbonate based aliphatic polyurethane coating. Incorporating hydroxy-terminated butadiene rubber as a polyol will insure good water resistance.

uh hmm..see #2.

It seems that the bamboo is more desirable when cut X-sectionally.

Once it is split the bookie calls all bets.

I'm using bamboo in designing a Japanese Restaurant right now. It's cool stuff. Try this site:

http://www.koolbamboo.com/

If you contact them directly I'm sure you'll get some questions answered.

Many types and varieties. For best longevity, it is said that a hole is drilled in each divided section so that solutions may enter and coat the inside also, for when the inevitable split occurs.

This is good site also: http://bamboocentral.org

One more tidbit (hmmm ... "tidbit" wonder where that word came from. Is it a unit of measurement? Ah .. that's fodder for another thread):

Bamboo is one of the strongest building materials. With a tensile strength superior to mild steel (withstands up to 52,000 Pounds of pressure psi) and a weight-to-strength ratio surpassing that of graphite, bamboo is the strongest growing woody plant on earth with one of the widest ranging habitats of more than 1500 species thriving in diverse terrain from sea level to 12,000 feet on every continent but the poles. It also grows the fastest: clocked shooting skyward at 2 inches an hour! Some species grow one and a half meters a day. For architectural purposes, Guadua is the favorite from among all the world's bamboo species. It's diameter is consistent for the first 15 meters and then at the top it becomes elegantly tapered. It has attracted the attention of civil engineers, architects, academics, designers, and artists.

I'm having a blast designing with it!

This is why it catched my eye in a bamboo fair in costa rica in 1993 ich. they were planning to market plywoods and other materials possibly parallams, microlams , etc composite beams. The market or should i say the trend of the day "durable" "sustainable" advocates will likely push for this "grass" for its fast growing ... still kind of problematic ramping growth. Where is the beef ? no serious datas yet on the capacities. Coated with epoxies , or even plywooded with good epoxies, could probably surpass classic materials. I keep searching and if not for now, it could be r & d. Today we had a ball working epoxies and bcfir ply. Hemingway's pool in Havana was in concrete and the rebars were bamboos. In our area, a friend of mine grows bamboo each year, it grows about 8 to 10 ft. he should bring them in for winter ... thanks people, i appreciate the brain storming. YC

Where is the beef ?

Beef is definitely NOT suitable for structural work...

It has potential.

Isn't that called "Mad-Cow Beef Jerky" in the US?

It's tasty, so you could chew as you glue it all together. Maybe you could use all that duct tape. Have you got lots of mad cows too ? I've seen some that are completely barking.

And you lot want to turn your 'bread-basket' into some kind of maze-ethanol sump don't you ? Maybe I'm just confoozed but I'm gonna winge/nag anyway 'cos something's pushing the price of bread up.

Dear Kris,

I am uncertain about the geographical position of your City in UK , but why dont you stop making totally useless comments that can only exacerbate the " Australian would be Republicans" (and probably the French Canadians as well ! ).

Do not get me wrong we ( as in the majority of Australians ) love, respect and actually know Her Majesty the Queen . The issues here are that most suscribers are serious. Indeed find serious comments an attraction generating as they do : usefull results.

We all appreciate good humour even when it is sarcastic, but it has to be of the quality for which original ( and Good Poms ) were once known for. At that time they were conscious of parcimonious useage. Try it.

Labor

I see absolutely nothing wrong with the French!!!

_{^{Lousy bunch of cheese eatin' surrender monkeys!!!}}

Ah... What? Did somebody say something just now?

I can't see much wrong with them either. That's probably because of the big expanse of water between my window and them. Or did you mean French-Canadians ? I can't comment on that, but I did see a few films about Americans getting lost in Southern swamps etc.

If you read the thread you might see the occasional useful bit of stuff I put in.

You are not a serious subscriber since you couldn't be bothered to sign in ( or perhaps just lacked the balls). You'll just have to wallow in your nostalgia (or something like that), and gurgle on the smug all-knowing drivel that seems to be dribbling from your mouth. Unless of course you sign in.

Gosh, wonder how much I meant that. You'll never know , will you.

Right on Kris.

As a further point for all concerned, particularly if someone comments in an unfriendly manner and also lacks the balls (please note the small "b" in this case) to be properly recognised, just completely ignore them, its the only way......

Think on old British manners from the 19th Century :-

"Children should be seen and not heard!"

I must have missed Kris' post that you are objecting to...

But the one you reply to has, interestingly, through humour, generated a serious point....

Re chewing of beef.......

Chewed sinew (chewing separates the fibres) is incredibly elastic and is used by many native cultures as a backing for bows, Native Americans and many Native African tribes use this. Indeed, the incredibly powerful Turkish Flight Bows use horn in compression and sinew in tension.

On a bamboo structure with torsion suspension such concepts are valuable...

However...as far as the politics goes....frankly my Dear I don't give a damn!

(Maybe us Brits afford our politicians less deference? This is a question not an accusation or argument or an indictment of anyone else politics, religion or lack of either ... )

Terms and condition apply...readers under the age of 18 must be accompanied by an irresponsible adult.

Replying to the Brits or Poms .

Let us carryon with the serious points and remember:

Honi soit qui mal y pense.

Labor

Humour is a very serious business.

If some of the more extreme religions/political parties could laugh at themselves maybe there would be less conflict?

Humour has a valuable role in brainstorming too as it allows the maddest ideas to be put forward without fear, and it is often those which hold the seed for a solution.

I do agree that bullying or racist taunts do not qualify as humour, however I'd like to think ours is generally relatively sharp, pithy or just off the wall.

Honey I think your silk stocking is down (1066 and all that)

We are more than able to mock ourselves.

(yes I do know what it really means)

Well said Del. Damned good show old chap.

It's my observation of CR4 (and life in general) that some of the best solutions are found 'out of the blue'. Sticking rigidly to some pre-conceived idea of how a problem should be addressed probably costs people dear. Many brilliant solutions come from the most unexpected sources, and in seemingly improbable ways. Some of the dafter threads in CR4 end up containing really good discussion of science and engineering, whereas many a straight-laced one drys up quickly. Having said that, it's a matter of choice/taste. If 'Guests' starts a thread, I'd suggest stating "no off topic comment please folk" and I'd be happy to do so (as I think most people would). Such a thread might be devoid of original ideas and inspiration, but it's a free world as they say. So as not to upset Guest, I'll go elsewhere for now Yellowcat. I'm sure you'll eventually find some of the links I might have provided here. It sure ain't worth bickering about.

Well said Del you old Puss.....

....and you are thinking "evilly"?

Something is pushing the price of bread up?! It ain't corn, unless you eat lots of corn bread...

It kind of goes like this - the most planted crop in the US is corn. Millions of acres of the stuff. Most of which goes to feed cattle for beef production. Cattle are the worst product for "food" per acre. What can I say, strong lobbies and pork-barrel politics.

However, even the cows can't eat that much corn. So, a lot gets shipped overseas, some to people that like corn and some to people that say, "Hey! What the heck is this crap?! What am I supposed to do with this?!" And a lot just rots (smut is the correct turn for the fungus) is silos. And Millions of acres simple go unplanted by farm subsidies (actually the least of all evils).

Anyway, if more acres laying fallow get planted with corn for fuel, and people stop eating so much beef, there should be plenty of farmland left over to feed almost everyone... That is when some dictator or rebel faction is not starving their own people to death.

It's such a happy world, isn't it, Walt!

Cows etc are very poor converters of energy, I agree. The trouble is that people like the taste. I shall have a look back to find the rising bread thing I mentioned. (yes, 'doh' I will need to check). There are some strange consequences of tinkering with how farmers do their jobs- knock on effects to ecology that they are often helping to sustain on the one hand, but kill on the other. As front-line people, they probably know most directly how this all works. I shall see if I can find one (CR4 is not exactly short of them). As to the role of 'politicians' re food, Mugabe is a good current example of worst-case scenario.

Dear Contributor,

I have returned to an earlier comment you made on this thread, You referred to millions of acres of corn. My question is what happens to this huge amount of grass that is left after the corn is harvested ? Is there an effort made to re-use same.? Is it in your mind to create a new thread ?. Judging by the comment I am almost certain it would be as successful as the "bamboo" one !

The query is : can it be used in bales and used as building blocks for housing.( This material (mostly wheat) has been frequently used in the colder areas of Australia for external walls. These are then plastered with a variety of natural products including earth - a lot of this attracts the" do -your- own- builder " ) Is this common in the USA and or Canada ?

Naturally this use may not be altogether suitable for suburbia (though it has been elsewhere) but certainly in the country side. Pardon my ignorance if that is already used in the States, but at the end of the day, we all have an obligation to question what is done or not done in order to save: waste and/or re-cycle what is not.

What are your thoughts ?

Thanks for the comments

LABOR

Here, mainly two things come in bails: hay and straw. Hay is used for cattle feed, and straw is mainly used for bedding material and to make it a little easier to pick up the droppings.

Straw bails are what's used in the US for building material. It's kind of taken off in the Southwest, where it gets really hot and it cuts down on the AC bills to have very thick, poorly thermal conducting walls.

As far as the leftovers from harvesting corn... Farmers help me out here! I believe that it is put in pits and used as "silage." Another form of cattle feed.

I thought i would add to this "sustainable" architecture idea for left overs from corn or any other bio products.

We used wood "spaghetti" panels dipped into cement for wrapping a product i made. There are panels that are made from a mixture of cement (concrete) and wood. They don't burn easily and last long against water damage. Wood or any fibers give an insulation R value to the products above what concrete does or doesn't. Concrete will add mass energy storage capacity and hence could be used for walls, floorings, roofs substrates. Easy to do for underdevelopped countries, mix like a cake, some of hightech products will require compression for structural purposes, it gives the product a sort of pre-stress. ie take a balloon, blow it 2/3 and it will be weak, squeeze it (pre-stress it) and it becomes stiff, strap it stiff (or glue it stiff) and it becomes a form of structural material. This is an analogy i use to explain invisible forces in architectural elements. The hay house has potential, but i would be worried if moisture gets into the walls, we had farms silos burning in the family due to that. Add cement "the glue and fire proofing " mixture into the hay (i would go 20% at least) seems a good idea. If we consider hay or corn left overs as renuable, trees will be happy. Bamboo is grass, so there you go for further developpement.

YC

I used garden bamboo sticks for temporary replacement for my delta kites, it worked for light winds, but for strong winds carbon sticks are the way to go. They splinter similarly when crashed, they hurt if you get a splinter into your skin.

Are you thinking of the kind of spontaneous combustion that can be brought about by moisture and micro organisms, like the way a compost pile can start smoking if not turned regularly? If yes, I'm not sure hay is susceptible to this. Not much food value. The only thing I've ever seen grow on hay is mushrooms. On the other hand, the only time I was around hay was while practicing archery.

Also, at least in Arizona they make a substantial effort to close the whole straw structure off - I believe with concrete.

By the way, I sent somebody here to help you cut up your bush-meat jerky...

He looks efficient, and he doesn't appear like he'd pinch the supplies. Some forms of jerky are in need of mincing, rather than just slicing etc. Heathrow airport Customs intercept bush-meat stashed in suitcases with regularity.eech.

Wow, you should be the spokesman/posterboy for the Bamboo Lobby! I'm serious, you almost gave me a woody! I am also jazzed about the renewed focus on natural sustainable materials, products and technologies (I'm working on a project to reclaim derelict farmland in Eastern Canada for switchgrass production).It seems to me that bamboo has a huge untapped potential.

OOBE,

I have a cutting board made of bamboo. It is a laminated structure made by adhering many strips together under pressure. The resulting plank is then planed smooth on both sides. It is one of the best cutting boards I have ever owned. The bamboo has a particular restistance to cutting (and I use a very sharp knife) without significantly dulling the blade.

I have seen bamboo flooring and it is very attractive. As a material, I like bamboo.

This discussion, and your post, has inspired me to include the possibility of using bamboo in some of my designs.

Mike

52000 psi,(this is tensions strength ?) if my calculations are correct for a 1/4" diameter bamboo, IIr2, ,125"x,125"x3,1416=,049 sqi, ie ,049 x 52000=2552 pounds. It can lift my car. I am going to do some testing with carbon sticks, bamboo, steel, alum., fiberglass, kevlar, etc. The best material will be the one that satisfies my load needs with the least elongation before failure. I will dip the sticks at both ends into a long nut filled with epoxy and screw a eyed bolt for loading at both ends. I will get some dynamics but what the hell, in a multihull, there is plenty of dynamic loads ...

Here's a link to mechanical properties. Even in the same species, the properties vary a lot, so you should probably go with the low end of the range -- and if you test, try lots of samples.

One reason aircraft spruce costs so much is that it is hand selected, and is very consistent from piece to piece. (Most of the spruce gets sold for less demanding applications). (You run into the same things to a lesser extent with Okume, which is available in Lloyds grades and lower -- I use the b/bb stuff, with is very high quality, but not Lloyds cert.) When you use bamboo, I'd guess you don't have anyone preselecting it for you, so you may need to be a little more conservative.

But even at the low end of the range in the tests done in the linked info, the stuff is very strong (over 20,000 psi). Modulus is a lot lower than I would have guessed tho.

BTW Avia sport was the vendor of carbon pultrusions I used. I not from their website that they no longer are advertising rectangular cross-section rods. they use to make a range of rectangular cross-sections (as well as rods and tubes, which they still make). One part of their website reads as if it is "now" 2001, so I wonder if they are still in business.

thanks, i went to avia sport, they seem to be in business. i clicked on link to mechanical properties, but my acrobat cant open it, do you have a web site name ?

52000 psi was a data posted which was impressive, ie 2500 pds for a 1/4" full round section ! this is quite a chalenge and to quality control it should be a task !

The test results from the properties link came us with about that figure for the top of the range (although in those funny fig newton units, if I recall). I think the range was almost 3:1.

I'll check re website.

I'm back before the edit time ran out. Here's the site http://bambus.rwth-aachen.de/eng/index.html

link #22 on this forum mentionned 52000 psi for bamboo ! is it stiffer or strongher than carbon ? I am going to test that. Carbon will be diifcult to glue to epoxy. On my kite bamboo was about 30% more flexible than the carbon sticks, but in all faireness, the bamboo i used was not perfect either. If i fill the inside of the bamboo sticks with epoxy, it will act as compression body and stiff it out . My wife will miss one more stick ... our secret !

oups, the wind is calling, its picking up.

later

YC

The bamboo is both less stiff and weaker than carbon pultrusions (and even hand layups). But carbon doesn't grow in your back yard.

This is a link to the same stuff, as sold by Aircraft Spruce.

Modulus is either 34 or 42 MSI (yes M!) and tensile strength is 500,000 psi or so, according to this (although if I remember correctly -- unlikely -- it was more like 300,000. strong, either way. Elongation to the point where it goes bang is 1.3% (again from memory) Compressive strength is close to as high, but of course it has to be supported against buckling. (maybe 500,000 whatever is right for tension -- for my application compression was the critical one -- so maybe that's what I'm remembering.) This stuff should be on the Avia website, but if it is, I couldn't find it with a quick check.

Thanks, but i don't know what tidbit means.

A good site to visit is on youtube and search for "defi petit navire grand prix" (in french) and "petit navire grand prix" (no words, but live comments in the boats). The Guadua bamboo is interesting. I will search for it, and my idea is to use it as strips, not hollow form, and the strips would be as small as possible in order to avoid spliting and voids. I have bamboo "zen" carpets and they are holding very well even in a watery environment. i.e. wet towels and splashes. The hollow sections were my first preferences for building torsion bars and beachraft frame, but i just inherited probably enough windsurfers fiberglass masts that i will use as the perimeter inner frame of the beachraft, for torsion bars, aluminum looks like my final decision. One interesting thing was to use bboo strips wrapped around swiming noodle (poly...) and all tied up with epoxy. But the noodles absorb water a pvc closed cell would be better. Of course, the main buoyancy will come from air tubes. Zodiac material for example. To be jacked up underneath the cat trampoline it will be very easy to lift or lower it at anchor. The Orange catamaran is impressive, isn't it. Best YC

The only thing I can think of that you'd have to take into account is whether you could get the strips thin enough to work well with resin. Glass in fiberglass is impermeable to liquid resin/epoxy, but this is compensated for by the thinness of the fibers. It would seem to me (IMHO), that if your bamboo fibers are too large, they might not have the density or strength of, say, good fiberglass.

Thanks Yellowcat for discovering the Green High-strength qualities in Bamboo.

In Assam where I live we have some 50 breeds .

OUTER 5>10 mm of some mature ones are stronger than steel and only 1.2 sp.gr.

I can supply you any qty. of such slivers-say upto 6m shipping lengths

Regarding strength-please go through "9th International Conf. Records on Inorganic-Bonded Composite Materials-VancouverB.C. Oct 2004.

And start with a talk to Mr.Fred Kurpiel at (678) 364-1900 in Georgia IMEAS Inc.

imeasus@aol.com

thanks. One interesting web site you can look at is www.multihulldesigns.com, kurt elaborates on the different techniques for hull const. my technique will be partly cylinder mold and strip. Strips will be used for specific tension loads for all wires attachments to the hulls. My design will resemble somewhat , look at "yves parlier mediatis elf aquitaine" catamaran on google. I will also have two masts (smaller in size) and various size kites for upper speeds performances, but the hulls will be wave piercing. The advantage with kites is that the loads are transfered directly to the hull, i.e. will not capsize as easy. There is video on myspace.com kitamaran. In my thinking bamboo could be interesting (i was planning to use carb. fiber and fiber glass) as it is somewhat nat. fiber mat. that could behave similar to joubert okoume ply. , easy to find in outposts in carabeans or polys.waters. Less expensive probably too. Tough on saw blades ... The cat will be built in 4 x 20ft hulls making a 40ft cat lenght. and 40 ft wide. it has to fit into a 21ft long garage in pieces. Sounds funny but i have repaired and dissasembled cats in my garage and the advantages are there. We are becoming the epoxy no air bubbles experts ... can't wait to test the bamboo strips with epoxy my wife found old bamboo carpets. Got to run, the wind is calling.

YellowCat, I think you are a great innovator/naval Architect/Structural Engineer

40'X40'Cat made in the garage-carried into the High Seas-raced with Kites aiding from the sky - I think you enjoy hard work with brains and brawn

And Cat after winning a racingTrophy comes back home to 21' garage and be wintered !!

Just spell out all you need--Diameter x length for masts/spreaders/hullframe beams.

And how many handwoven 1mm thickx 4'x8' bamboo mats to wrap skins over the hull frames,tie them down and plaster with Epoxy to make watertight.

On getting your list I shall come back to you with a list of possible sizes/weights.

Can we fit everything into a 20' Containerload to ship out via Singapore/Vancouver?

hi mukulmahant there are many reasons why it has to be a modular cat. 1 - easy maintenance , repairs, construction. 2 - easy , sort of, transportation from one test water body to another. the idea is to be able to put pieces onto a trailer(s) and pull it with a car or suv. 3 - lightness, because it will have no 100 ft mast dead center, the structure needs only to support 2 masts , nearer to the supports. Also, If you look at how kites work, the power generated for its weight is tremendous. For example, my kites are certainly 40% more efficient than the same area in a sail. Why ? because you end up with the surface where you want it i.e. like a swimmer, if you push in water with your arms in a straight line, you are less efficient than if you "s" your movement. It is the same in air. Other things are impressive with kites, go to youtube and search for flysurfer. You will understand how a kite can generate power with so little wind. The masts are there for approaches, take offs, and storm sails. 4 - Sort of like a hobie cat 16 , the trampoline shall be on "posts" for water clearance, and possibly suspension. Independant suspension ! This may seem crazy, but it will take less burden on the structure in a busy sea. Still refining the options. Would bamboo's capacities play a role ? I have not considered it yet. Torsion bars at first glance ??? I know this is hard to picture, i did a couple of scale models for my wife. KISS principle is the key. If you are interested, when i finish the drawings, i will modelize them. A good friend offered to do it so that he and other friends can understand. He is one of the at first incredule ... With Okoume ply, i need to scarf the ends ... look at Kurt's web site. A wovened bamboo strips one piece 20 ft x 5 ft h. x 1.5 ft w. amas, that would be easy to epoxy layers together onto a cylinder mold. The outer skins needs to be fair, so is okoume ply. A 45 deg. woven would be stronger. I await your infos on weight. At 1mm thick, should be interesting. Winterize ? I have 4 babies to winterize, not another one ! Thanks YC

Torsion bars at first glance ?

I'd worry about bamboo in torsion. Although it has phenomenal compressive and tensile strength (in line with the grain) it splits easily, and can, I think, be relatively easily sheared parallel to the grain. When you put such stuff in torsion, you are causing such a shear force. (This is why carbon fiber torsion tubes, and even tubular beams, have several plies at 45 - 45 in addition to the longitudinal unidirectional plies.)

Also, when using it in tension, you'll want to make sure that at fastener locations you do something to prevent splitting (wrapping in Kevlar thread in epoxy would be about ideal.)

I like the idea of your boat. I've built a few, and am always dreaming about building a cruising cat powered by a wing (but not of the hang-on-and-scream variety like the avatar pic).

Re scarfing: I put the sheets on a table which has a little shim across the end that my circular saw rides on (with the saw held on its side, so that the base plate is facing the end of the table.) The shim sets the scarf angle, and the saw is set for 90 degrees. Pretty fast and easy.

Great project!

thanks Ken Kevlar is partly involved for specific uses as huricanne "proof" shelter section. One of my good friend just hapen to be an expert in Kevlar. Kevlar is also considered for projectile protection. With wind blowing at high speeds, for instance, my neighbor in Florida had his house destroyed from palm trees debree flying thru the walls and windows. The only way my house got destroyed is with bulldozers for new condo construction. My kevlar design ended up the same as my friend's designs by coincidence. He looked at me (mouth opened) lets do this together, we should get unbeatable prices ... although Kevlar is interesting, it has major flaws with UV s and water. Fiberglass flooded in epoxy seems to be the best compromise so far. Wrapped around a sonotube on a rotating axis, it would be done in no time at 45/45 ... also. The rest is at R & D and classified stage. Perhaps bamboo could have potential soaked in epoxy and wrapped with fg fibers. Cost and weight are key. The general thinking is if could find it at large scale sales in a lumber yard, it should be easily available and cheaper. Bamboo should be cheap and easily available in the tropics. A boat is like a building with interactions between elements that will determine longevity, aesthetiics and comfort. It floats on water instead of earth. Got ot run, got to install a J24 spinaker onto a prindle 16, dont ask... YC

Got ot run, got to install a J24 spinaker onto a prindle 16, dont ask...

No need to ask. We clearly have a lot in common... and should both be institutionalized. Although wouldn't a Melges 24 asymmetric on a long (bamboo) sprit be more fun yet?

BTW, another boat I built was a proa along the lines of some of Bernard Smith's ideas. The geometry works out a lot like kite geometry, in that it is possible to cancel healing moment entirely. Mine was based on a pirogue I'd built earlier, and sailing it was almost eery. Perfectly flat in gusts. A small float was to leeward, and that float was large enough to support part of the rig weight (the rest being supported by the main hull.) You could imagine that if you managed to get the wind on the wrong side of the sail (which was canted 45 degrees or so) that you could bury this small float -- but even that did not occur on my little boat -- and, in fact, the vectors again work out advantageously, with that condition tending to press the entire boat, not just the float, into the water. I'd be tempted to make a 50' version (very skinny main hull (maybe a max of four people sleeping end to end, no amenities whatsoever) for fast cruising.

proa was my first idea, it has alot of advantages. In fact the cat configuration can benefit from some proa caracteristics. one interesting is that it can become a monohull easier for docking. i kind of like the backward and forward capabilities of the hulls. in fact having a rudder at both ends has been done on charante maritime at the quebec / st-malo race. it can turn on a dime. needs a crash fin in front though. mast inclination is on the same side. one interesting aspect of kiting especially with the flysurfers, as seen on youtube, the speed kite is flying all over the place and the power turbine are dead stoped or slowly turning. in very light winds (6knts) we are able to ride while others sit and watch. i did not meter my speed, but at 8 knots of wind, i had the feeling i was going 20 knots. When water (2 to 6 inches) sits on top of the ice (min of 12 inches ... ) in a melt down in winter, put snow skates (mini skis) and enjoy the skins on the beach feeling non stop ... make sure your ski boots are water tight or loke a wetsuite, we froze the first outings, but could not bare to stop ...

you are a boat builder, do you use okoume ply and epoxy ? a dream of ours if we would win a lotery would be to build an extreme class looking like the old americas class with huge sails , like a star, and the hulls would be finished like babyface nelson (epoxy works), nice wooden clear epoxy finish.

An asymetrical spi would be better, i put a genoa last year with downwind and sidewinds better, but upwind aerodynamics problems. The best trial will be my 13 m speed kite if only we can get the favored wind direction.

you are a boat builder, do you use okoume ply and epoxy

Yes, it's great stuff to work with. I also have used carbon unidirectional fabrics and of course fiberglass cloths, but I can't really say I like working with them. Wood, however, I enjoy. The whole epoxy process is a little stressful, I find. I'm always rushing to get things done before it starts to cure too much... but then I find I do a lot of waiting for the final cure.

I've even extended okume into my current project, which is a prototype for an Automotive X Prize contender. This started before the X Prize as a fully-enclosed motor scooter, and eventually grew another wheel, and became a little car. But the original monocoque tub body, much larger than the donor scooter, and completely enclosed... was lighter and stiffer (in torsion and bending) than the scooter frame alone.

Funny, your america's cup style boat is nearly identical to yet another boat I've been dreaming of building.

Another thing I did: a wing I'd get inside of when on ice skates.

i put ice skates blades on my old v20 wooden skis. on ice, it was deadly, i ended up ahead of my kite because of my weight inertia, and fast, i mean fast. with a 30 mhp wind, i was close to 55 mph trying to slow down otherwise the sky was the limit. my teacher at school of architecture, built ice boats out of wood. my neighbor bought one in metal, but got scared, these things are awsome. for now i stick to kiting on snow skis in winter, and soon on kitamaran wind permitting.

i have an opinion on synthetic materials, they are very srtong and each have its modulus of elasticity, i e i would recommend pre-tensionning before setting in epoxy or resins. woods have a more predictable behaviour for post-stretching causing cracks and long term delamination. it is possible to evaluate safely the maximum tension on a structure, ie apply that safe tension at wet out. the olympic stadium in montreal was built that way ... nevertheless, carbon is much stiffer and should have less stretch, but brittle. bamboo should be interesting to stretch out because of its rings that would act as steel rebars ribs. should not stretch too much before shear at the attachment at both ends. my guess.

i agree that it is stressfull at wet out and predicting gel state. 205 is kind of a compromise but one has to work on schedule and temperatures kept to as low as possible (the substrate has to be warmer than the air) lets say 65 to 70 f . above that i would use 206 or even 209 . Filler silice makes it harden faster it seems, at least on my tools.

got to run

yc

re carbon and pre stressing:

I used carbon fiber pultrusions on the boat in my pic. These are about twice as strong and stiff as unidirectional hand laid carbon fiber laid up to aircraft standards, for the reasons you'd expect: all the fibers are straight, and share the load equally. In a hand layup, first the straightest fiber breaks, then the next, and the next...

By happy coincidence, these putrusions were much less expensive that the fabric and resin required to equal them -- and infinitely faster to work with.

Carbon fibers pultrusions sounds like a good idea for high tension loads, bottom ctre of bilge, shrouds attachements, etc. Hockey sticks and delta kite's members can be re-used cheaply. I will test them first for quality control ... for the sides of the amas, 45 degre woven carbon could be expensive but strong reinforcement for the okoume. This is hard to pre-tension, that is my concern for cracking and delamination. Bamboo strips, i found little zen bamboo carpeting ready to have a new carreer, could do the job. I will test them against carbon left overs. Don't tell my wife where the carpet went.

It will give me the oportunity to check my epoxy on site strength.

That's what i like about wood is that the layup is easy, the fibers are already pre-glued together ... and aligned properly too.

By the way, i just found out an idea for mast ups and downs. Besides the advantage of having two masts for sideway ups & downs, i could use the main sail hoist track to keep the mast going where i want it and pivot the base so the mast can slide frontward(bow-ward), using the shrouds as lateral stabilisers, once it gets near the ctre of the mast, IT becomes weightless. Flotation in water can play a part too.

How well does carbon fiber work for arrow shafts with a compound bow?

Great! My supplier of pultrusions started as a kite stick and arrow shaft producer. If you're interested, I'll dig up the name, which I can't recollect right now.

I remembered -- Avia Sport. Link in post 88.

Is that nano-tube carbon-fiber or some of the plain sort ?

Kris asked me to drop these off to you...

http://www.bambooboats.com/construction.html

http://www.americanbamboo.org/GeneralInfoPages/BambooAsMaterial.html

http://www.electriclamb.org/AFP/pages/151.html

http://www.inbar.int/publication/txt/tr18/physical%20and%20mech.htm

http://www.romanconcrete.com/docs/bamboo1966/BambooReinforcedConcreteFeb1966.htm

Congratulations,

The stuff you have located is sensational. Thank you. It makes following these threads enjoyable and most usefull.

Best Regards,

Although my building days are far behind me, if I was 30 years younger, I think that I would be planning later today a new multi-hull!!! Thanks for all the great posts everyone...

This blog has proved to be one of the most interesting for me that I have read for a long time.

If all is true about the relative strengths with regard to other materials, why are F1 experts still using aluminium honeycomb and carbon fiber???

I expect therefore one of the following to become true in the next couple of years:-

1) F1 cars have incorporated bamboo in the construction of parts that must be very light but strong.

or

2) Carbon fiber and aluminium honeycomb would be a better building material for the job in hand (boat building), but not cheaper than 1) of course.

Epoxy works issue 22, a formula car 's trailer done in okoume ply. and epoxy. I wonder if bamboo ply wood do as well as carbon. Probably heavier, but lighter in the pocketbook ... just finished a small project using bc fir ply and epoxy, working just fine. We are using the trailer for removing blue algeas floating ashore. Algeas are so heavy when wet and yet so light when dry !!!??? I don't think so, don't even think about it. But hay, who knows ... a play of words doesn't hurt .

YC

How about blue-green algae and/or bamboo as biofuel source?

Algea is so thin and dry when dry ... euh... too airy, like pine needles, they burn too fast. Bamboo would probably be too dense, this grass destroys the blades. Like white birch, it burns but not like maple or oak. Then again i am not much of an expert in wood burning other than using maple syrup tree as fuel ... smells good. Won't be permited for long, global warming. Instead we use part manufactured logs that last 2 hres, a mix of wax and wood wastes. Some people use algea for medicine, apparently bue algea has some benefits, i don't remember what it is.

Had a great sail today, following a classic Stiletto .

YC

Here's a fun one... Go get yourself several bamboo sticks about an inch in diameter and 2½ feet long. Go into your house and start a nice cheery fire in the fireplace. Once the fire is going well, throw the bamboo on the fire. Guess what happens!

in small pieces like that, it probably will behave like strips of hard wood, good for fire starting. i used a bamboo stick for lighting my fireworks with a flare at the end of it. we wetted the cane at first, at least on surface, it doesn't absorb water easily, could be because it was varnished ...