Questions About Bamboo Backed Hickory?

[WoodBenderDW]

I had a reliable source tell me that bamboo backed hickory is a  bad idea because the back will overpower the belly and cause the belly to fail. Yet, a lot of people people make bamboo backed hickory bows. Is there any truth to that? Is there anything that should be done differently? Should the back be trapped? Should the belly be hear treated? Will bamboo allow a shorter piece of hickory to work the way sinew would? Will a hickory stave that's 61 inches long work for a stiff handle recurve bow if backed with bamboo or is that still too short and better to bend through the handle? Thanks folks.

[Pat B]

Bamboo is very strong in tension. Hickory is also strong in tension but not so strong in compression. IMO, it is not a good combo. A short hickory stave is even more susceptible to compression failure if backed with bamboo, a recurve would add more stress to the hickory belly.
 If I were to make a boo backed hickory it would be long and trapped with the hickory belly being wider than the boo backing.

[Msturm]

I have made a few BBH bows. all 3 of them were in the 65 in plus range and pulled from 40-55 lbs . All of them took a lot of set. and 2 of them have real bad compression fractures to the point where I didn't feel safe shooting them anymore and they got burned.. I think Bamboo is too strong in tension for the hickory. Ipe works great, I bet osage and any other pretty high density strong in compression wood.   Keep in mind that I have limited experience with these materials

[leonwood]

Hickory is so strong in tension that for a 61" long recurve it would hold up better without a backing! Then if you insist on backing it, it is better to back it with maple or ash or even hazel because these woods match the level of compression for hickory better than bamboo.

[RatherBinTheWoods]

Yew back boo...so good they even made it rhyme :0)

[Eric Krewson]

I have made 3 or 4 bamboo backed hickory bows, all were really sorry, poorly tillered hickory bows that other people had. I made a mistake and opened my mouth about how bad they were and the immediate response was "can you fix it ?"

I would take these awful bows and bamboo back them, all made really nice bows, none of them failed or developed frets. All were in the 40-50# range and at least 64" NTN. I made them all about 1 1/4" wide with very narrow tips and a non working handle. I would add a couple inches of reflex on the glue-up.

I found bamboo backed hickory to be almost as zippy as a BBO.

[joachimM]

Any backing and belly combination needs to take the qualities of each material into consideration, and change the ratios of thickness of both, bow length and bow width.

For strong backings likely to overpower the belly: make the backings thinner, and make the bow wider, and thinner or longer (so as to strain the belly less). Wider bows have more mass, so shift the most bending limb portions towards the handle (pyramid designs for example), so the mass is placed most where it has least negative effects.
 
Hickory is good enough in compression at very low moisture levels (5%). Toasting the belly will help (as heat-treatment reduces the equilibrium MC).

Bamboo-backed hickory bows can be exceptionally good, if designed very well. See for example Traditional bowyer's bible vol 3, chapter on "bows of the world". Plenty of examples there, and concrete suggestions as for ratios of different types of backing to core/belly wood.

[TRiggs]

I have a Boo backed Hickory bow that is 7 years old and shoots great and I can't see it not lasting another 7 years.

[bushboy]

If I where to try,i would pre tiller to about 20lds at your draw,heat treat the belly and after glue up trap the back heavily.

[bushboy]

I ment glue a narrow strip of bamboo down the middle for the trap and adjust from there.

[Eric Krewson]

Lots of opinions of what you should or shouldn't do from people who haven't made a BBH.

A few of us have made good bows from the combination, like any other bow making endeavor, design and dead on tillering is the key to success.

I have never trapped a bows belly in 20 years of bow making although I have seen it suggested quite often.

I have made a bamboo back oak bow that failed on the tillering tree but I suspect it was the gorilla glue I used on the glue up to see if it would work, it didn't

[bushboy]

Lots of opinions of what you should or shouldn't do from people who haven't made a BBH.

A few of us have made good bows from the combination, like any other bow making endeavor, design and dead on tillering is the key to success.

I have never trapped a bows belly in 20 years of bow making although I have seen it suggested quite often.

I have made a bamboo back oak bow that failed on the tillering tree but I suspect it was the gorilla glue I used on the glue up to see if it would work, it didn't

I guess you have a crystal ball or other means to determine someone's context!wish I had such marvelous powers!i have glued up several and reported my findings only to be little by the likes of you!by the way,the back is trapped not the belly!

[Pappy]

  No experience with glue up, just reading and following.
 Pappy

[Eric Krewson]

Wow! No belittling, just giving my experience with the combination, yours has been different and your input is a good thing. What I a saying is bamboo backed hickory can be done, I have done it a bunch of times, just offering a different perspective. There is no way I can predict what another person's outcome will be as we all make bows differently.

I was referring to the people who offer concrete advice like it is the gospel but with no actual experience, real common here.

I know what part to narrow while trapping, been doing this bow making stuff for 20 years, made a lot of bows. I think I am up to 154 that I know of and no telling how many that I didn't put down in my log book.

How many bows do you have under your belt?

 

[PatM]

You can trap either side depending on your combo.  I made two bows to establish that.