Bamboo backing - to taper or not to taper, that is the question

[kiltedcelt]

My only experience with bamboo backing so far have been the pre-tapered pieces that David Knight sells to go along with one of his r/d glue-up. With his r/d bows the taper of the boo is beneficial to getting the quickly tillered design that goes along with his pre-tapered cores. If I'm working with woods other than ipe, say any white wood or perhaps osage, can I use a bamboo backing strip with a parallel taper, or is it better to taper the piece so it's thinner at the tip ends? From what I've read and seen, most guys use other backing woods like hickory in a straight taper, which is to say no taper at all, simply the same thickness over the entire length of the backing strip. What is the maximum thickness you would go with for a bamboo backing? Maybe 1/8" from the highest point of the curve of the bamboo as measured down to the flat gluing edge? Also, an add-on question - with hickory backing what's the maximum allowable thickness? I've read of guys using hickory that is almost 3/16" thick and ending up having correspondingly thin belly wood. The end result is kind of weird looking from what I understand but seems to work okay. However, most examples of hickory backing I've seen have typically been 1/8" nominal thickness.

[tattoo dave]

I've only built a couple with bamboo, but both of them had zero taper on the back. One is all bamboo, back, belly, and core. Just the core was tapered. I'm not sure of max thickness, but both of the ones I worked on were 1/8''.

[Pat B]

When you work with boo backing you want to cut out the profile of the bow first and then thin it to 1/8" at the fades. If you thin it first before cutting it to profile the tips will be way too thick.
  You can go with a parallel boo backing just like with hickory. It will work fine. With hickory I cut the backing strip at 3/16" and after sanding both sides it comes out about 1/8" or less. That is plenty thick enough for a hickory backing. And more just adds extra weight to the tips where you don't want it.
  On my first hickory backed ipe I made the limbs about 1 1/2" wide and by final tiller the backing was twice as thick as the belly. It shot well but did look strange. For ipe or osage 1 1/4" or less width is what you want.

[ShinneryOak]

Pat, do you thin it enough that it's flat on the glue surface before cutting out the profile and then thin it again?

[Pat B]

The pieces I bought were somewhat flat on the underside except for a bit of concavity down the center. I would trace the rough bow shape on the underside and cut it out then flatten on my belt sander. Once you trim it down to the exact shape you want thin it until it is 1/8" at the crown. You can taper it to the tips or not. Usually with a 1 1/4" to 1 3/8" wide bow you will have a knife edge down both sides of the boo or maybe 1/16" along the edges of the boo.

[Marc St Louis]

If you cut out the profile of the Bamboo to that of the bow first and then thin it to a knife edge from centre to tip you will a natural thickness taper

[bigcountry]

If you cut out the profile of the Bamboo to that of the bow first and then thin it to a knife edge from centre to tip you will a natural thickness taper

I am going to do this next time.  First time, I had same thickness, which was well over 1/8".  I then trapped the boo on the edges, like Dean Torges does.  I am not sure that was a good idea to expose those power fibers by trapping. I started getting burrs or splinters lifting when I got close to finish tillering.

So next time I plan to knife edge so no power fibers are exposed.

Great tip wish I followed.