Bamboo Backed Hickory Questions

[TaylorJohn]

Hey there Tradgangers! It's been quite some time since I've visited the site. But, the fall has come, and the archery fire within has been re-ignited.

A couple years ago I built a pure maple board bow. My first bow, and it turned out quite well. Unfortunately, it's taken on some set and has more handshock than I'd like so... time to build another one!

 

 
My brother shooting it.


My plan is to build a bamboo backed hickory bow. I'd like it to be somewhere in the 45-55# @ 28" range. I am also really interested in making a static recurve, and I have a few questions before I get started:

1) If I back the bow with bamboo, is the grain on the hickory board super critical? If it runs off the edge for example, do I need to worry? Or will the bamboo backing keep all in order.

2) If I go for the recurve, do I heat/clamp the wood to bend the curves before or after I do the glue-up?

3) Can I use regular carpenters glue? I've heard Titebond III is the stuff to use, but I'm on a budget.

4) What sort of NTN length should I be looking at? I'd like to go shorter if possible.

5) Is there a website with rough dimensions to build such a bow? My first bow followed Ferret's board bow design, and that made things much easier for a novice like myself.

So, whaddaya say guys? I would love to hear your wisdom!

[Pat B]

IMO, backing hickory with boo is not a good pairing especially for someone that has only built a few bows. Many have done it and successfully but there are better options. Adding a recurve is adding more stress to it so you have to be very careful with your tillering. A wood that is stronger in compression strength would be better as a belly lam; osage or ipe.
  Generally the grain of the belly wood is not as critical with a backed bow as with self bows but the better the grain the better the bow.
  Hickory bends better with wet heat; steam or boiling.
  For 28" draw, twice the draw length plus 10% or more is a good starting point.
  Regular carpenters glue will work fine for boo backings. I have used it successfully with hickory, osage, yew, ipe and other belly woods. Urac is the best wood/wood glue out there and might be a better option.

[TaylorJohn]

All right then, so I'd be better of starting with Osage. Thanks for the tip!

[Pat B]

Yes! Osage is very strong in compression and can take the stresses the very strong in tension bamboo will impart. You can use the hickory for backing strips. It makes very good backing and good stave selfbows or board selfbows.

[TaylorJohn]

Thanks Pat,

Another question:

If I back with bamboo, how thick approximately should my osage be? I was thinking of using the bamboo backing sold on the 3rivers site.

[Pat B]

I never measure thickness. I just remove wood until I get the bow I want. For osage boards I prefer to start with thicker belly stock(5/8" to 3/4") so the added handle riser sits above the plain of the limbs and is less likely to flex and pop off. From there I use a rasp and scraper to reduce the belly then go to just the scraper for final tiller.
   The boo should also be reduced to 1/8" at it's crown at the handle. From there it can be either tapered to the tips or left parallel to the tips. Be sure to cut out the bows outline with the boo first before you thin it or the tips will be too thick.