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Beyond Bone Dry!

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Hamish:
"It was 62" long, stiff handle, top limb 1.5"  longer than bottom.  Approximate width of just under 1.5" from fades to start of taper then even taper to tips.  Parallel max width portion of limbs was ~11' then the taper.  ~ 6" of stiffer tips that were reflexed to just shy of recurved, and the tips were working some.  1/8' positive tiller, and the bend looked great.  I was using a 12 strand b-50 string and bow was pulling 34.7# at 27"...my 12 yo son's freakishly ape armed current DL."

Yep, it's a little narrow for your low humidity. I'd try 1&3/4" or even more for osage and see how you go. Even a 2-2&1/4" wide pyramid osage would be a good option.You could also make the overall length 64-66" for an extra margin of safety.

You probably won't even need to fire harden to get great results with hickory in your climate.

Another option is to back your osage with a good hickory or boo backing strip.

Muskyman:
Could you put your Osage in a room with a humidifier? Staves and bows both. Then just keep an eye on there moisture content to see how much moisture they need in the room. Just a thought I had. Hickory does make a good bow if you want to go that route. Fire hardening does help with it absorbing moisture but you can over do it if you’re not careful.
Good luck

Doug509:
I've been having similar issues with pacific yew staves breaking at only 40lbs draw weight during tillering. I tested moisture in a 6hr vacuum oven and found moisture ranges from 3.5 to 4.5%.   May have to move my stash to the bathroom shower or apply sinew.

Pat B:
Does your house have humidity control with the a/c? At what r/h is inside your house? If high enough your bow wood should acclimatize over a week or two. Most bow woods like to be between 9% and 11% m/c. Hickory preforms best at 5% to 6%. In your environment hickory should be perfect and make a damn fast bow.

ssrhythm:
Ok...I have no idea what our inside RH is, but since we are running central AC in the summer, I'd think it is lower than the outside RH...but I'm not sure.  I've ordered a hygrometer for my shop, and I'm looking into the best humidifier set up to be able to maintain a desired RH of 30-40% in that sized room.

I pulled down another stave, and chased a ring the day after the bow-explosion.  I've been keeping it in my bathroom with the AC duct off in there, and everyone I take a bath, I leave the water in and have been suspending the stave over the water unless I'm working it.  I now have it worked down to where I'm about to start tillering.  The bow/stave is again in the bathroom, and it's good and humid in there.

I have a pin style moisture meter that read the moisture today before I started thinning down the limbs at 6-7%.  I just broke one of the pins off trying to get it to sink in the osage a bit, so I'm looking for advice on a better way to go.  Will a painless meter work on bow staves or does it have to lay flat on a flat piece of wood.

Anyway...the biggest factor causing that bow to break, I believe, was that it had a concave furrow running the length of the stave on the back that ran off either side about 10 inches from each tip.  After reading up on how hollow limb bows actually work...ie the curve actually flattens out as the bow is drawn...I now understand that there was tremendous strain in the center of that furrow where it ran off the edge of the limb.  It's clear as day that the failure initiated at that point on the top limb, and when it did, the ultra dry wood just blew all the way back to the fade. 
 
Hopefully, a more normal, flat backed stave with a bit of re-humidification will result in a bow that won't blow.

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