Yew sapwood, to thin or not to thin?

[Red Dwarf]

I am attempting my first yew selfbow. It will be an American rather than English style longbow and I am aiming for 63" nock to nock and 45# at 26".
The question I have at this time (I am sure that there will be many more as things progress) is whether or not to thin down the sapwood. The current thickness of the sapwood is 3/8" and, considering the lighter poundage I am going for, I am concerned at the possibility of losing all of the heartwood at the tips of the bow.

Any/all comments will be most welcome.


Thanks


Red Dwarf

[BigArcher]

When I built my first Yew longbow several years ago, I did not thin the sapwood because the growth rings seemed too small and light colored to follow.  When  I went down to Northwest Archery, which was still in operation as a store, I got the chance to talk to Glenn St Charles and his son, Joe,(I think).  They both commented that I hadn't thinned the Sapwood.  When I exspressed my concerns over following a growth ring, they said it didn't matter in the sapwood and that they would have taken it down to under a quarter inch. I have built a few since then and have thinned.  I don't have much more experience than that. The yew bows I have built and used have lasted a couple of years of regular shooting before giving up the ghost catastrophically. They were in the 80# range and close to 70 to 72 inches.
 I haven't done a Yew bow in awhile but that is what I remember.
Good luck.

BigArcher

[Tom Leemans]

I thought I read once that it should be no more than 1/4th the thickness of the limb. (Something like that)

[Jason Jelinek]

When I made mine I thinned the sapwood down to 1/4" thick and it worked great.  I didn't follow the growth rings either.  Keeping the bow long helps too.  Mine was 73" for a 29" draw (12" stiff handle).

[Red Dwarf]

So, the general direction so far seems to be that I should thin the sapwood to around 1/4" and that following a growth ring is not necessary.
Anyone else have thoughts on this?

I am a little nervous about the growth ring thing.

Red Dwarf

[crosseye]

i have never made a yew bow, but i saw some staves, and there is no way to follow those growth rings...i'll bet they were 25-35 per inch.  pick up the traditional bowyers bible vol 1, as it has an entire chapter dedicated to yew bows.  if the growth rings make you nervous, back it with something.

stan

[John Scifres]

You can follow a ring but on the really thin stuff, 60-70 rings per inch. you don't have to.  I like it to be unifromely thick and less than 1/4".  That'll make it a nice 20% or so of your thickness on a 50-70# bow.

[Ted Fry]

I usually thin the sapwood so that when I am finished I have 2/3 heart wood and 1/3 sap .
You do not have to follow 1 growth ring but I have found it best to follow the natural conture of the back .
Also a good idea to back it with rawhide as the sap wood is very easily damaged if you drop it  or drop something on it.