couple of yew questions

[stuckinthemud]

I have a really knotty piece of yew branch which I intend sinewing. I have carved off nearly all the sapwood most of which is now only two or three rings thick, heavily violated and down to the heartwood in places as I smoothed out the lumps and bumps.  Then I laid in the tapers and just as I got the tapers cut I found a nasty punky black area in the centre of each limb, really weird, mid limb same size and same depth  and same length.  Anyway, I now have a hollow in the centre of each limb.  Two questions.  Should I extend the hollows right along the limbs or just leave the middle of the limbs hollowed?  Now my tapers are useless as in I have no idea what the hollows have done to my tiller, how far can I bend this before I sinew it? I currently have 2 inches of tip movement, this being most of its reflex (it has 3" of natural reflex).  Presumably I should run the hollows out along the limbs and go for a HLB and I guess I should sinew and worry about the tiller once its cured???

Thanks in advance
Andrew

[Del the cat]

There is normally a black pith channel down the centre of a Yew branch, about 3mm diameter. You can ignore it, leave it as a guide line or fill it with glitter mixed with clear epoxy 
If it's a big patch of rot that was formed by some injury to the tree you can dig it all out and let in a patch/ sliver of wood.
I had a gorgeous half Yew log, but it turned out there was a rotten ring that had grown over when the limb was about 1" diameter. There was still enough good wood, but I had to let in a wedge of wood where the damage had started.
You can see it in the first minute or so of this vid:-
https://www.youtube.com/watch?v=5XusABh7tFI&t=6s
Del