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Main Boards => PowWow => Topic started by: Chuck Hoopes on January 26, 2009, 06:50:00 PM

Title: Ring orientation reversal on boardbow??
Post by: Chuck Hoopes on January 26, 2009, 06:50:00 PM
Thinking out of the box here.  What do you think?  Situation: I have made several hickory board bows, orientating the growth rings so that the outer rings form the back of the bow. In other words the top of the arch of the cirle of the ring.

Alhough hickory has very good tension strenght, I have found the compression strength to be just fair.  Iam thinking that since I back these bows anyway, and am not concerned about breakage, why not reverse the ring orientation.  This way the top of the ring arch forms the belly of the bow. My thinking here is that the compression strength would be increased- similar to the princple of the Roman Arch.  Are these just the musings of a Madman?  :knothead:    Has anyone tried this?  What do you think?
Title: Re: Ring orientation reversal on boardbow??
Post by: trashwood on January 27, 2009, 12:01:00 AM
I think you are going against the natural phyics of growth rings, having the crown of the stave as the belly but ya never know till ya try.  I have used quarter sawn hickory boards backed with flat sawn hickory backing that showd more to resistance to compression.  One of the biggest things regarding hickory is ya got to keep it's mositure content down even when bow is sealed well.

rusty
Title: Re: Ring orientation reversal on boardbow??
Post by: Jim now in Kentucky on January 27, 2009, 12:43:00 AM
In TBB I, there is a discussion of "backward" bows. These were made with the outer ring the belly and the core side of the stave for the back.

Ancient examples of that design have been found, so there is a precedent. I say give it a try.

Reparrow man
Title: Re: Ring orientation reversal on boardbow??
Post by: George Tsoukalas on January 27, 2009, 12:48:00 AM
Me too. It won't matter either way. Jawge
Title: Re: Ring orientation reversal on boardbow??
Post by: trashwood on January 27, 2009, 07:57:00 AM
well; there ya go the expert has spoken.  Lets us know what you find out  :)

rusty
Title: Re: Ring orientation reversal on boardbow??
Post by: Jason Jelinek on January 27, 2009, 10:21:00 AM
I've heard you can increase the compression elasticity of whitewoods by slightly charing the belly with a heat gun or fire.  It doesn't work as well on osage since it is already elastic in compression.  I believe the charing keeps the very outer cells of the belly wood from absorbing moisture as quickly.

Marc St. Louis has been doing this for years with success.

I want to try this with White Ash on an ELB design in the next few years.

Jason