Bamboo backing question

[Roy from Pa]

I use Maso Bamboo for backing bows. Normaly I have no problems. However this winter, we have had the back of the boo splinter up on 3 or 4 bows. I was told by another guy that Tonkin Bamboo is way better and stronger for backing bows. Any thoughts or suggestions guys? Thanks, Roy

[Steve Kendrot]

Dean Torges's website says he uses Maso over Moso, but when I ordered my Tonkin Bamboo from Mike Westvang, he told me Dean uses Tonkin that he also orders from Mike (Dryad bows). It seems like I've also seen contradictory advise to this lately and that many people use Bamboo and Ratan Works and I haven't seen Tonkin slats advertised there. I don't know how you tell the difference, but I ordered five peices of Tonkin from Mike. Hope to get it glued on soon!

[razorsharptokill]

I just got two pc. of tonkin from Mike that look way better than the stuff I've bought from Franks. We'll see.

[Eric Krewson]

I had a rash of failures from Frank's bamboo and quit using it.

[Roy from Pa]

I have been buying my Maso from Bamboo and Ratan Works in New Jersey for 2 years now, but out of the last 6 pieces of Maso I got from them, so far 4 Bows have splintered on the back. Tells me something is not right. I may try Tonkin soon.

[Roy from Pa]

Make that 5 bows. Another one just splintered up tonight, had it to 22 inchens on the tree and POW. I am ready to chew nails here. I had to get a bad batch of boo. Going to call the company tomorrow.

[mmgrode]

It seems as though a lot of the strength of the bamboo has to do with the individual piece you get and, with it being a natural material, there is inherent variability in the product itself.  I have made good bows from both species, but personally, I have had better luck with maso from Bamboo & Rattan than I've had with tonkin, especially in making heavy weight bows...no doubt! Tonkin for lams, but maso for backs for me.  Many things could factor into this:  How are you drying your bamboo(very important!)?  What are you using for clamps/forms?  How wide and thick are you leaving the boo on the back? What are you using for glue? What kind of weights were you pulling the bow to? There is also a possibility that you got a string of bad product.  Call them up...they should replace it if that's the case.  Also, with any bamboo be sure not to leave a sharp edge/corner anywhere on the edges of the backing.  These places are conducive to lifting a splinter(I've found that out the hard way).    Matt

[razorsharptokill]

Knife edge on the boo or leave a little "meat" on there?

[Roy from Pa]

I feel so dumb right now. I sent mmgrode a PM and he replied. He asked if I placed anything between the clamps and the back of the boo when clamping up the bow.  

Well I used to use a soft 1/8th thick piece of plastic between the clamps and back of the boo. But it got so messy from all the glue ups, that I threw it away and started using nothing between the clamps and boo. I can see now where that was my huge mistake! Sometimes the clamps would leave a very slight mark on the boo, as in a depression. I would take it out with a scraper and fine sand paper. However that slight depression had to fracture the integrity of the boo deeper down inside.  

Matt thanks for the heads up, Roy Real Dumb In Pa:)

[horseapple]

Dang Roy I'm dissapointed in you:) Find you some strips of 10-12oz latigo leather for the back and 1/8" aluminuim stock for the belly.

JD

[Eric Krewson]

I use 1" long pieces of scrap bamboo for clamp pads on the bamboo back. I leave it raw and not flattened so the inside curvature matches the back.

[horseapple]

Good idea Eric, I once used 1" square pieces of osage that was curved on the belly for my protection, but found that I have better results and alot less time with the tapered leather strips, also I kept nocking the bucket over that was holding my osage blocks:) Also I tried gluing thick pieces of leather on my clamps but the leather would come off after awhile, probably wasn't using the right glue    

JD

[Walt Francis]

I use 1 1/2" X 1 1/2" X 1/4" pieces of pine cut from a scrap piece of 2x4 on both sides of the C clamps and haven’t had any problems with dents.  Pieces of cork work even better.  Also, I watch the amount of pressure applied with the clamps and found if I apply enough to dent the Boo then I might be starving the glue joint of glue.  Hopefully, I will have the new form finished by tomorrow evening and we can use the air/fire hose for the next glue up.

JD, I tried the same thing with five or six types of glue without any success and finally gave up.  Thinking about it now, I think that MT-13 would work because it is designed to glue wood and other porous materials to metal.

[J.F. Miller]

when I glue bamboo on the back of an osage slat I use a full length clamp "pad" that I made from a piece of hickory backing(1/8" thick) that didn't measure up with a piece of the most dense carpet padding  I could find glued to it with contact cement. the thing was about 1 1/2" wide and about 66" long. plenty well flimsy enough to conform to radical deflex/reflex profiles and even mild recurves. I chose the carpet pad because it can form around the nodes on bamboo and help disperse the clamp pressure everywhere else, but still provide protection. the hickory also helps protect, distribute clamp pressure, and provides a stable, rigid surface for the clamp. lay a piece of cellophane on the bow between the bamboo and the pad to keep from gluing pad to bamboo. I don't know how many dozens of bows I glued up with this rig, but it worked very, very well for only a couple of dollars. I've since made an upgraded version, replacing carpet pad with a strip of dense foam rubber floor mat(an anti-fatigue mat, I guess), which is about 5/16" thick. got the floor mat material from Mr. Torges hisself. this version works even better than the original. does a better job of distributing clamp pressure, I think, because the foam rubber is much more dense than the carpet pad, but still spongy enough to protect.

I've never really had any problems with Maso Bamboo from Bamboo and Rattan Works. the bamboo I've gotten from them has always been very good. the nicest bamboo I've ever used is Madake, which came from Australia. cannot get it here, as far as I know.

[Scott F]

Sorry about your luck Roy.  I have had exceptional glue lines as soon as I started using bicycle innertubes as a wrap instead of using clamps.  I cut them in half length-wise and wrap the bow from each handle to each tip.  I use titebond III glue and wrap it about as tight as I can.  After the bow is bound I use only enough clamps to push the bow into the amount of reflex and/or deflex that I want.  The bands can be used over and over again and for the price of one 5" clamp you can glue up dozens of bows.  Some people use innertubes from the trash cans of bicycle shops for an even cheaper source of banding material.  The best part of this method is that you don't have to worry about clamping pressure since it is even throughout the length of the bow.  This has worked for both bamboo and maple backings.  Ensuring that you have two FLAT gluing surfaces is the most time consuming part of this method.

[Roy from Pa]

Thanks guys for not coming down too hard on me, except for that Horseapple fellow:) LOL

[horseapple]

Roy, sometimes a quick kick in the butt helps:) Wakes you up.

JD

[tradbowr]

Roy
   Could the Boo just be at fault?

[Roy from Pa]

It wasn't the boo this time, it was my error..

[Dale Hajas]

Just use a couple dozen wood screws and fasten the dang stuff on there and quit yer fussin!