Boo/Hickory/Yew

 I've finished the Replacement for the bow that exploded, it's a whisker under 90# @32" draw.
Using Microsoft 'Paint' I've managed to produced a combined unstrung and full draw image.
I've sisnce taken a couple of scrapes off the ringht outer limb as it appears a tad stiff when I drew ellipses on the full draw image.

Someone suggested the tiller was odd and the outers are too stiff (I do tend to agree, but it was glued up with a hint of reflex)...
For everyone who says a whip tillered bow is fastest, someone else says a Mollegabet style with stiff outerlimbs is fastest. So make your own minds up and tiller accordingly!

Bad day at the Office

 I got the deflexed yew back to 70# @ 28" and took it roving on a scorching hot day. It felt punchy. One of the guys videoed me shooting it and I heard it creak... I inspected the back and couldn't see any lifting splinters, so next shot I pulled it a whisker more (maybe 29"? ... it was supposed to be 29" draw).. I thought, I'll hold it for a couple of secoBANG. It exploded whacking my right forearm in the process. 

We collected the pieces and carried on round the rove... nearing the end my calf suddenly went into spasm and I slowly limped off to sit in the shade and play my harmonica (that's not a euphemism) until everyone finished. We then sat around chatting and enjoying a cool drink.
I think there were two problems whith the bow, a knot at the centre was much deeper than I suspected, but even if filled would probably have still failed. I suspect the real problem was the sapwood was too thin.
Being a small diametre stave (smallest in the upper limb) the back needed to be rounded to follow a ring, by flattening it a bit I left it V thin down the centre about 2mm. (see diagram).

To try and see if this theory is true I sawed some cross section through near the 2 main breaks. It seems there was plenty of sapwood at the grip, but it was thinner near the knot and at the other break... that's the problem with a stave , it's not nice and even so it's difficult to draw sound conclusions.

Tidy up and Deflexed Yew ELB

 I had a sort through my staves to make room for the storm damage yew I'd just processed. The old staves were a bit of a rag bag mix, a couple of good ones, two that were just too skinny and bent and 3 staves of Elm. I'd had a go with one bit of the Elm previously, but it was too full of burrs, which looked good but were too unsound. I had a quick look at the best of the Elm, removing the bark, but it had a huge cavity and a load of burrs, so I decided to scrap all the Elm.
Whilst tidying I got chatting to my neigbour, who said he had a wood burner, ideal! I sawed up all the Yew off cuts and the scrap staves and left them in a plie in his garden for him, that saves me a tip to the trip.

One of the good Yew staves looked fine for a 70# elb, which my mate Rob had requested, he may well have given me the yew originally as the Elm which was on the same shelf was from him (the Elm was always "it may be ok, or it may be useless... worth a look".
The yew is from a fairly small diameter shoot/trunk/limb and has a good bit of deflex... 62mm from the floor to the belly at the grip, when placed with the tips touching the floor. It had been roughed down to appox' dimensions previously, so I just cut temporary nocks and tried it on the tiller. Plenty of draw weight to play with.
The sapwood is lovely on one side of the bow but slightly discoloured at one end on the other side. A bit of drawknife work on both sapwood and belly got the draw weight to 70# @22" with slightly taut string.

I then strapped the bow flat and heat treated the belly to try and remove some of the deflex. There was a good improvement with it being reduced from 62mm to 32mm, I may steam or heat a hint of reflex into the tips as they have a hint of ugly deflex at the moment. 
I've had to plug a few knots too, but I'm faily confident it will make a nice 70# @ 29"