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Take down yew bow project.

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superdav95:
I’m posting this failure in particular to maybe help others out there that have thoughts of trying the same to possibly provide some insights perhaps and some words of caution.  I started this project last year and kind of just set it aside to recently start on it again. This was two separate pieces of yew billets that were of good quality. However  I now think it was a bad idea to use yew as a candidate for a take down socket and tenon using epoxy and or fg wrap.  A better use of these billets would have been a z splice.    You’ll see from the pics here that I’ve added horn and other hardwood inserts to stiffen up the tenon a bit as this build progressed.  I then added the 2 steel rods as a little more insurance.  This was all done as a fix for the sloppy loose fit of the tenon into the socket with just the yew wood alone.  It would shake loose and basically fall apart on me. Yew it too soft to hold a solid shape for a tenon.   I couldn’t even continue to tiller till I remedied this first.    I’ll post some pics here to explain why I think it’s a bad idea and to do an autopsy of sorts of the why it failed.  I did have hopes that it would work in the end and it was looking very good for bend.  I had it braced low with long string and was pulling to get it to 25” draw at 55lbs when it exploded.  My goal was 60lbs at 28-29”.  Bend was looking very good up to that point prior to exploding on me.   I had done some minor heat corrections on tip twist and a mild reflex in the bending limbs maybe an inch.  The main issue of failure was at the tenon where I cut into the sapwood in order to redo the tenon the second time for tighter fit.  The tenon fit nice and tight but left a week spot there at the cut layers of sapwood.  Is it possible that this could have worked if I did not have to redo the tenon and cut into the sapwood?  Yes but I do  think it’s worth the risk.  Will I attempt another one of these using yew?  No.  A better option for take down would be a brass and steel sleeve perhaps keeping sure to not violate the sapwood at crucial spots at the same spots.

Anyway I figured I post this failure firstly to warn any others thinking of doing anything similar to be aware of my struggles and the conclusions I came to and why.  The other reason is to show that failures happen sometimes. 

Thanks for looking guys.  Hope it helps out someone out there. 

Happy building!   

PEARL DRUMS:
Dave, I had a similar failure using brass/steel sleeves. The portion that slides into the sleeves has to be fully intact. I approached mine the same as you did here. That squared off area of the male portion slid into the sleeve. That's where it peeled up and failed in dramatic fashion, very similar to yours. I essentially violated the back and we all know that cant happen. I'm not sure what I typed fully explains my scenario. It's difficult to put into words.

Muskyman:
Well, way to scare a guy to death.. Here I am in the middle of trying to make my first yew bow and now that’s two I’ve seen on here that have exploded..
Sorry to hear about your bow Dave. Sucks for sure. I’m sure my time is coming.  (--)

Hamish:
Even if you can't see any bend, and the handle/fades are supposed to be stiff, there is still plenty of tension stress going on.
The use of a step down at the back part of the male tenon, automatically creates a weakness. Some people manage to get away with it, more by luck than by design, and it seems to be popular with fg bowyers. Fg bows tend to have longer stiff fades, and deeper handles.

Its a real shame because that bow was lookin real classy before it popped.

You are right about cause and remedy, as you mentioned in your assessment. Try another TD, just don't cut into the handle on the back, any more than minor adjustments to make it match the other billet, and feel good in the hand.

superdav95:
Pearl drums. I hear ya.  Here’s a couple pics of my tenon and socket prior to redoing it as it got very loose on me I think because of the softer yew wood compared to other bow woods.  You can see from the pics that at that time k had maintained the sapwood for the most part knowing that this would likley be an issue.  Turns out it was in explosive fashion. 

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