AZ Ironwood Bow

[richgibula]

I have used an epoxy treatment that works on softer woods.  I used it a lot on things like walking sticks made of yucca stems to improve their reliability and prevent unexpected cracking or deep scratches.

The ways it works is to mix up your favorite strong epoxy. I use West Systems or Pro Set which have a tensile strength in the range of 8000 to 11,000 psi.  You mix it well, then you add enough acetone to make it thinner than water.  How much this takes depends on the epoxy viscosity and temperature.

Rub the mixture into the wood until it does not absorb any more.  Wipe down any access on the surface unless you want a glossy look later, but it might be irregular. It will take days to dry because the acetone first needs to evaporate from inside the wood, then the epoxy can gel. If you want to coat it later, do a light sanding to improve adhesion. Remember that this mixture is very flammable.

I am sure that this improves compression strength on a soft walking stick, but I have no idea what will actually happen on a very hard wood. I am sure there is some "case hardening" going on and there will be better scratch resistance since the coating penetrates deeper than a varnish. Of course, these is not a "primitive" solution to anything but it is a neat trick that has made my yucca walking sticks survive over a decade of use. (It took a long time to find ones that have the right thickness, length and nice looking curves and then apply leather grips.) 

[richgibula]

I have been looking for a handle wood and I found this piece of firewood that I got from family in Colorado. I am not sure what it is but it is most likely Russian Olive. The only other firewood out there was a pine. Any other ID ideas?

[simk]

Looks very close to laburnum

[richgibula]

Since this is a board and very hard, are there some recommended dimensions that would be best for a bow?  I have made bows from 68" to 48" but not from a board.  I am assuming I will use a strong backing.
Thanks for your help.

[Hamish]

Dimensions??? I'd go around 1 &1/4" maybe 1&3/8" wide for a flatbow as you are dealing with an unknown quantity, in regard to chrysalling.
 If it holds up you can always start to narrow the width rather than the belly whilst tillering.

Length, start at 68" if you have the length in your billets. You can always pike it later if necessary. Glue in around 2" of reflex with the backing.

[richgibula]

Thanks Hamish.  Based on the continuous parts without splits, I can make up to 1 1/2 inches wide but I will have to butt-join 2 halves together for length.  I have done that part successfully before. With that I can make it to 68 inches.
I am worried that its such hard wood that the draw weight will be huge.

[joachimM]

I am worried that its such hard wood that the draw weight will be huge.

The point of tillering is to balance the to limbs and to get to the desired draw weight. So there's no reason why the draw weight should be huge other than by the choice you make. In fact, your bow will be hardly any thinner at 50# than a regular hardwood bow. 

[richgibula]

Since I am trying to conserve the Ironwood, how thick of a piece do you think I should start with when I cut it to shape the bow?

[willie]

In reviewing this thread, I see suggestions for a different backing, and some discussion of a different wood for a handle.

have you considered laminated designs that minimize the use of the ironwood, reserving it for just the belly portion of each limb? the ironwood would only need to be a lam 1/3 of the limb thickness or thinner depending on the core lams, and need only be long enough to extend through the working part of the limb and into the fade.

[richgibula]

Interesting thought. The other wood needs to be contrasting. I wonder what I can find in a lighter color, maybe maple or hickory?

[Hamish]

If you use boo for backing, maple would make a nice core wood, contrasting with the AZ ironwood. If you used hickory for a backing, then maple wouldn't look as good(less contrast). Purpleheart or wenge would look good, as would cherry.

[richgibula]

Good thought.  I wonder if there isn't a back wood that would not need additional backing.  I guess I could always use a bamboo stave.

[willie]

with the ironwood being so heavy, even hickory would be lighter and could serve as a backing and a middle, perhaps a a single piece with the the ironwood lam on the bellyside. you would of course want to pick a design that would make this construction easy.   long easy ramps into the handle, etc.
maybe non working stiffer tips if you are limited in ironwood lam length......

with all the experience available at this forum, opening a different thread exploring design possibilities for such a bow might be interesting

[richgibula]

I am not sure what to say on a different thread for design purposes that is not already here, but I love the thought of design ideas.

The longest section I can cut out of the Ironwood piece with the proper grain orientation is about 51 inches before I hit the first split.  At that length, I can make the piece very thick or make two thin pieces.

Alternatively I can splice two shorter pieces, originally side-by-side in the board, to any length you would want in a bow. 

If I use a backing wood then the Ironwood part can be at 51 inches while the back could be longer.

I am open to any design ideas.

[willie]

reference pic