Advice on some twisty undulating yew

[Alex C]

This is my first time working with yew and I've got this stave with a bit of a quirk at one end.  It's a bit hard to describe, but the picture helps - it's a combination of twist, bend, and highly undulating crown height.  My main concern is how to deal with that undulating crown as the sapwood is only 1/8" to 1/4" thick, and that fact that it's in a bend at the same place is no help.

My current plan is to follow the grain with my centerline and then flattening the leftover crown as much as the remaining sapwood will allow.  The problem is that the grain runs off to the right of the stave at around the 64" and I'm a little concerned about not having any safety net there.  How bad does yew respond to not following the grain?  Would it be a bad idea to cheat the grain a bit there?

Goal is a flatbow in the 55# @ 28" range and around 64-66" ntn with flipped tips. 





Thanks in advance for any advice! Just trying to exercise my patience with this stave and get it right since I don't know when I'll have a piece of yew again.

[superdav95]

Well I might try and do some heat correction with heat gun and oil after you get the bow roughly shaped to get the troubled area back in line to where you want.  Don’t over heat it and you should be fine.  Don’t heat correct some spot more then once to be safe.  I would avoid grain run off as much as possible.  Yew is ok as far a violation of ring on back but I would caution against grain run violation.  If you do decide to flatten the back and violate the grown rings on some portions of the back you can just back it with rawhide after as safety measure.    As far as the rolling hills and valleys on the sapwood back I would not flatten this too much if it were me.  I would just follow this same hills and valleys on the belly as best as you can. It’s more work for sure.    It’s a character stave and will be really sharp if you pull it off and will shoot well.  Just follow those contours on the belly to maintain the same thickness working down the limb.  Best of luck. 

[MattOwens]

My experience is very limited compared to most here, but most of the bows I make are of yew. I think it'll depend on who you ask, but I've seen yew bows decrowned with zero regards to the grain and they turn out just fine and others that thin sapwood but are cautious and feather out every ring violation gradually. I live in a very dry climate (central oregon) so I favor the cautious side as I've heard yew selfbows and dry climates can end in a bang. I like to sinew back or rawhide just for security after thinning sapwood.  Others will chime in with more experience and knowledge. Check out Clay Hayes on you tube, a few months ago he built a yew recurve and thinned the sapwood without any concerns over grain violations. 

[Del the cat]

If the sap wood is only 1/8 - 1/4" you are a lucky man!
Just leave it alone if possible, don't worry too much about following the grain.
Regarding any decrowning:_ If you really have to, then proceed with caution as the heart/sap boundary doesn't necessarilly follow the contour of the underbark surface. Also those undulating ridges are a nice character feature.
Sapwood can be feather out carefully towards the edges, and some of the high crown taken down a tad without too much concern, but I try to leave the back if possible.
It doesn't need much heartwood to  make the bow work well.
Any steam bending, twist removal can be done when the bow is part tillered with no problem. Yew responds well to steam bending and heat treating.
Del

[Aksel]

Nice looking stave. If anything, I would make sure I round off the sides of the back properly, toward the tips incase you have deep ridges and valleys there.

[Alex C]

Thanks for the advice guys!  I'll l eave the sapwood fully intact for now until I can see what everything looks like once the bow is laid out.  In regards to backing, I read somewhere that sinew can pull yew sapwood away from the heartwood - anyone ever seen that? 

[superdav95]

I have also heard this too but I have yet to try it myself.  I’ve backed them with rawhide or the like but I know Gordon on here has done one that I know of that turned out very well.  He posted a build along years ago.  It is possible to do from what others have said.  It’s on my list of things to try also.  If and when I do try this I will keep the sinew amount to about 60-70 grams for standard 64” bow.  My think here is the hopefully avoid lifting or delaminating the sapwood. 

[Del the cat]

I know I say don't worry about following the grain... but I just came across this post from my blog which shows there are limits!
https://bowyersdiary.blogspot.com/2016/09/exploding-bows.html
Del

[Alex C]

I know I say don't worry about following the grain... but I just came across this post from my blog which shows there are limits!
https://bowyersdiary.blogspot.com/2016/09/exploding-bows.html
Del

Thanks Del, that's EXACTLY what I'm worried about here!  It looks like the grain actually follows those ridges on the back, but it's hard to be sure.  The majority of the working limb is pretty straight, so I think I have a small bit of safety net there.  I'll just keep the tips REALLY wide, like no taper at all, until I can be sure of what the grain is doing under those ridges.  That way I can do the taper with the grain afterwards if that makes sense.

[simk]

These ridges clearly indicate spiral growth. So first mistake was selecting this tree for harvest. Can't follow the grain now and gotta live with an increased risk of failure. Jm2c
Edit: Backing it with rawhide/sinew/linnen will bring you back to the safe side.