Thursday, 31 October 2013
Yew Warbow Stave
The big Yew Warbow stave is now beginning to look like a bow, I've glued on temporary nocks of Elm and I've slimmed the tips and started reducing the belly a bit to get it flexing.
I've been pulling it on a hemp rope which will just fit onto the bow, it's difficult to know how stiff it should be, but having done the Elm bow I've got a feel for it. I also put the Elm bow up on the tiller using the same rope and pulled it back until the tips were back to a brace height. It took about 55# pull.
So using that figure for comparison the Yew looks on track for a good high draw weight. I was pulling it to about 130# and the tips weren't getting quite back the 6" to brace height.
The bow is certainly flexing. Originally most of the bend was near the grip and I've been taking down the outer limbs mostly. I'm taking dimensions from one of the Mary Rose bows as a starting point and it's still a bit above those, but the waggles in the stave mean it has to be done by eye and feel, not by numbers.
Some of the knots have already been removed as the belly has been worked down. The back still has it's cambium layer, which I'm expecting to crack off with a loud bang once the bow really starts moving.
I'm certainly not going to rush this one as we are sort of aiming for as much poundage as I can get from the wood without over straining it. John the guy I'm making it for pulls the 100# Elm without breaking sweat, and has pulled 120# comfortably. (Oh to be young and fit!) Anyhow, I'm thinking if I aim for 150#, I'll hopefully hit 140#, so no chance of me pulling it. Shooting it in and testing it will be interesting.
The stave has a little natural deflex, this is quite handy as it doesn't try to flip off the tiller.
This post shows the limb when it was still in the tree.