Bamboo question...

[akila]

Hi all....i just  buy 2 poles of bamboo...i realy dont know whatt speacies is..but you will see in the pictures...that the nodes are pretty faar away 30cm one from another.....i have something that i wanna show you.....i know that on bamboo its best that the power fibers to be as much as posibile to the surface ...but it something strange to this bamboo...to one end it seams that the bamboo is thinner and to the other end its verry thick...and the power fibers seam to be  in the middle of the bamboo wall....and something els i wanna ask you....this poles wass not split....i found themm like this...and they have many little splits all over the  lenght....you think that this 2 piecces of bamboo are ruined al ready? it seams that iff i scrap  that outer skinn...some off the little splits are disepearing.....but i have a fiew that i think  they are a liitle moore deept thenn that...i will put some pictures and i wait for your replays....


Here you can see the craks in the bamboo...some of themm are not verry deept...but i have a fiew that i think they are deeper...



And here is what i wass talking aboute....it seams that the power fibers are in the middle of the wall and not to the surface of the wall...or maybe this is how it should be...its the first time i work with bamboo so i dont have experience with this....i just buy this 2 pieces of bamboo as a learning process...
This is the wider end of the bamboo...

And this is the thicker end...\

[akila]

Hi again....i did something...i have cut a small piece of bamboo....and i did some sanding on the cut surface....and here it is....


I see now the power fibers.....i wass a little confused abute that thickk wall and that line from the middle...
And here is a little sanding on that splits...that i wass tlalking aboute...

You can see that after a little sanding they seem to disapear...most of the splits are like this one...not verry deep..but aniway i have a fiew that are a little deeper thenn this...probably i will try to cut trhu those splits so that i dont loose to much material....i hope....

[Ryano]

akila, The power fibers look fine to me. The cracks kinda concern me though, I'd try to work around them if at all possible.

[akila]

Hmmm..yess im a little afraid  becose off that craks.......well i will see iff i can do something....i wanted to ask you guys something els...im trying to make an asiatic bow...made  from to strips of bambooo glue together....and maybe with sinew....do you think that i have to respect the roule...that i shoud not have a knot in the handle area....im thinking that in an asiatic bow...the bendin area begin to aboute 3" from the center...and if i put the knot of bamboo right in the center, i will have the hall limbs withoute knot at all....but iff i put the  center of the bow between 2 knots, thenn i will have 1 knot on each limb right in the middle of the limb, where the limbs do most of the bending part???what do you think aboute that???

[Pat B]

Are you talking about boo back and belly with sinew added to the back?  If so, you will have a problem with sinew sticking to bamboo back. You could temper(heat treat) the boo and use that for the belly and add sinew to the inside of the boo and use that as the back.  ( )  it makes since to me but maybe nobody else!     Pat

[akila]

I see...i think that this is what i wass trying to say...but i must say that i have seen an asiatic bow made from bambooo...an the belly  wass made from raw bamboo....and the core also from bambooo...but i think that the core wass flat on bouth sides.....and thenn sinew....i dont know iff i should have a knot in the midle or not..... i know that on long bows this is not a good ideea to put a knot in the middle of the handle....but on asiatic you think its the same......???thks a lot....for replays....i realy dont know what i will do with those little craks....i will try to put some hide glue in those cracks....i have read that longitudinal cracks are not realy verry bad....its somthing common in bamboo bow to apear such cracks....specialy on Yummy bows....but i dont know....this is all the material that i have to work so i have to deal with this problems some how...

[Pat B]

Generally when you use boo on the belly of a bow you want to temper it first. This will increase the compression strength. Boo is very strong in tension but not so in compression...unless you temper it.
 The longitudinal cracks should not be a problem. Can you select a section from the round that is not cracked?    Pat

[akila]

Hi....i just split on pole of bamboo...i have 4 pieceas  32"long for asiatic bows...and 5 pieces  68" long for long bows backing.....i think that i have a fiew pieces that are ok...with no cracks... i know how abute this tempering thing of bamboo...it must be done to the inside of the boo, and i have to be carrefull not to burn the boo....but i realy dont know iff its ok to put the nodes in the handle of the bow, or  between 2 nodes.....and i dont know iff i should use a core of bamboo flooring and the belly made from raw bamboo....or iff its ok just to use one strip of bamboo , that will be my core and be :-\lly to....

[Pat B]

The node in the handle will be fine but you could also have a node on either side of the handle. As long as it is bending smoothly there should be no problems. I have only made a few boo backed bows and none with boo belly. Of the boo backed bows I've made most were 66" to 68".  I would like to make an all boo bow with raw boo back, tempered boo belly with a bend through the handle design. Maybe add a bit of riser between the boo at the handle.     Pat

[akila]

Yess me to....this is why i have those long strips of bamboo...i wanna try a trilam maybe, or 2 lams glue together and a handle  in the middle...