Primitive Archer
Main Discussion Area => Bows => Topic started by: Aries on August 12, 2009, 05:36:06 pm
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In light of my recent bow failure several new questions about the properties of bamboo have arisen to me. I was under the assumption that all bamboo was good bamboo but several people have agreed that bad bamboo was the cause of the recent break on my latest bbo bow. My questions are...
1) What separates good bamboo from bad bamboo
2) What signs if any would there be to look for when selecting a piece of boo for a bow backing
3) Is the occurrence of "bad" bamboo a fluke in its growth process, or is it inherent in certain species of bamboo
4) is there a specific range of thickness that bamboo should fall in to be coincidered good for bow backing?
Thanks guys Ty
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I think that your problem is in the species of boo you used.. I have seen the (as I call it) double noded bamboo fail consistently as yours did..
(http://i312.photobucket.com/albums/ll323/knight3169/index.jpg)
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Ah i can see where the issue would be with that. Here is a pic of the rest of the stock that i recieved from the same trade. It all appears to have the double node to me because of my new cinical view of boo :P, what do you think?
[attachment deleted by admin]
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Hey for what it's worth, I agree, I only use mosco bamboo that I usely purchase from dealers that trade in High quality boo, Woodcrafters, jim boswell at rudder bows is another . I plan to harvest my own, I hooked up with a pro that is going to show me how to grow. The double power fiber joint definitely is a waring signal. I even had a small kids rd bow break there too. And it poundage was only about 30 lbs, good luck , hope this might help. Denny
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Only Moso bamboo for me. Just proven stuff. You can feel it is promising. I've held other bamboo stuff from various bamboo species, but none feel as solid and hard as moso.
Other than the species, I think you should avoid:
- Too many nodes (1 node per feet is about right)
- Excessive fungus growing on/in the bamboo. Superficial is fine, as long as you can wipe it off. But you sometimes see bamboo poles with dark spalted spots. Avoid those!
- Poles with longitudinal cracks/checks in them. Boo can dry pretty bad in low RH. It can check in a few days. Those checks are difficult to deal with.
- Poles with scratches on them that go deeper than the rind.
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Thanks again darksoul very informative. Ive been doin my research and i keep seein your moso bamboo pop up everwhere i look lol I guess Ill go with the flow on this one.
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First I want say most bamboo species for sale you buy is ok for the bow.
It is not species, but quality.....
The bamboo I see in picture not pass my standard.
It is poorly dried, the rind is green so they never dried in sunlight to bring tan color.
Bamboo dried this way seem soft to me, not as strong.
The black colour is just a dirt or fungus, it should have been cleaned off after pole was cut...sometimes it will degrade bamboo if left.
It not matter if double node or single. Single is just easier to scrape rind...
Madake, use for the yumi is double node bamboo. It is strong!
Young bamboo is never good for bow, you need 2~3 year old bamboo.
Most bamboo supplier not cut young bamboo, but I guess they may if in short supplies.....
Other than that, DarkSoul advice is good.
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Thank you as well far east archer.. While we're on the subject, how do you go about the drying process yourself. I recieved this boo green through a trade and just tossed it in my hot box for a while and after a couple weeks let it set in the sun for a couple days.
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Hot box?
This method work, but I never try myself...
Most important is the bamboo dry without degrade, if degrade, it will fail.
It is hard to tell you, you need know when it cut.
In winter, moisture content is low, so easier to dry without crack.
Split into slat and dry in sun for two weeks. This "bleach" bamboo, after, you let dry in air circulated area that is dry.
In summer, its full moisture so it cannot be dried so rapid in sun.
Unfortunately if you do not cut own pole, this method is not possible...unless sender dries for you.
Cut bamboo, leave full length with branch and leave. Let sit in sun, the leaves will steal moisture from bamboo pole and it dries it out.
After leaves die, cut top off and dry in circulated area.
Though! Bamboo all different, like a human, so sometime even with good method it can crack.....unfortunately.
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Good bamboo:
(http://i30.photobucket.com/albums/c316/JorikSwier/Bamboo/Bamboo15.jpg)
Note: there is no node in this section of boo, about 1' x 1"
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A node is not the only reason , boo breaks, You can over stress any wood , especially if it is too dry. Dean Torges builds a hot box and puts a 60 watt bulb in it, If i recall its about 125 degrees in his box, for about 3 days, should do the trick. Usually the boo seems a bit curved when it is dry. Have a couple of his videos. Hope i got the ifo right. Good luck Denny