Reducing yew sapwood

[DC]

How do you guys arrive at a uniform thickness when you're reducing yew sapwood? The only place you can see the thickness is at the tips and along the sides and the appearance along the sides can vary according to the crown. Do you just follow a ring as best as you can and damn the violations? I know yew can take a few. I could use Del's method and go down til the heartwood shows and then back up a step but I'm having trouble mastering that technique

[Del the cat]

You've pretty much said it all.
I go fairly close with a drawknife taking it to about say 1/4" you can roughly follow a ring(unless they are V fine) using the edges as a thickness guide... when in doubt stop and pencil a L for 'leave' on it. Holding the spokeshave with the blade actually vertical and using it as a scraper will help show the rings as it roughs up the softer edges. I tend to leave it like that until it starts to move on the tiller and then keep cleaning it up buy degrees. At the bow progress there is less back to tidy up... you would n't want to chase a ring on a whole quarter log.
Bcause the heart sap boundary doesn't always follow round the rings and it isn't always consistent thickness I don't get obsessive about following a continuous ring, but I do try to get any violations running along the bow if possible, or at an angle and always blended in smoothly.
It's sometimes a trade off between an even thickness and following a ring, sometimes its just not possible to have both!
I expect you've seen this pic before, but it shows what I mean... the bow is still going strong after about 43 years, it was the first ever Yew longbow I made... it had me in tears at times as I made it 'cos we didn't have the internet and a PA forum full of experience to help us. If I could go back and tell myself what to do it would have been easier .... a challenging stave for my first ever, but it's mellowed to a gorgeous colour.
If I hadn't reduced the sapwood I'd have had no heartwood on the belly. I try to have at least 50% heartwood, but the stave dictates what you can do.
I've only violated 8 rings in the space of about 6" so that's fine
Out of interest, I recently refurbished that bow, heat treated the belly and pulled out some set, The belly cracked where the heartwood was thin by that big sapwood dip. I put in a deep curved patch, slimmed the tips, added delicate horn nocks and it now shoots further than when I first made it... that's what 40years of experience adds
Del

[DC]

Thanks Del. Have you found that reducing the sapwood reduces the amount of set the bow takes? I seem to think that I read somewhere that yew sapwood takes set.

[wizardgoat]

Ya I just pencil a line on the sides measured up from the heartwood line.
as del has said before, you can either have 1 ring or a even thickness, not both

[Del the cat]

Thanks Del. Have you found that reducing the sapwood reduces the amount of set the bow takes? I seem to think that I read somewhere that yew sapwood takes set.

Dunno really, too much variation in the individual staves to make generallisation IMO.
Like I said there often isn't any choice... you just make the best bow from the wood you have, I've had some with V thin sapwood and some where it's thick.
The worst Yew I've had was where the wood goes sap, heart, sap, heart and some of it doesn't know what the heck it is. That seemed a tad rubbery compared with the best Yew, but a good dose of heat treating seemed to make it into a decent bow. I think even the poorest Yew is still very good bow wood, and beautiful to work. Of course if its rotten you are screwed, but it will stand up to knots and violations and checks as long as you respect it and try to make the best bow you can.
Del

[sieddy]

Hi guys I hope you won't mind me jumping in to this thread with another question? 
When reducing the sapwood on a Yew stave do I need to leave the knots alone? I've read that with Orange it's necessary to leave little islands of wood round the knots on the back. Is this a good approach with Yew? Thanks in advance! 

[Del the cat]

Hi guys I hope you won't mind me jumping in to this thread with another question? 
When reducing the sapwood on a Yew stave do I need to leave the knots alone? I've read that with Orange it's necessary to leave little islands of wood round the knots on the back. Is this a good approach with Yew? Thanks in advance! 

Yeah, better too much than too little.
Plugging knots on the belly is good, but it doesn't help on the back, best thing is to make sure you don't disrupt the flow of sapwood round the knot and if it's really big or bad, rasp out a shallow dip and put a long sapwood overlay to bridge over the knot.
Del

[DC]

I'm just about ready to brace this bow I'm working on. On one limb(billets) the sapwood and heartwood are about the same thickness. If I decide to thin out the sapwood do I do it as part of the tillering process ( scrape the back instead of the belly)or do I try to go down a ring or two(or three) all at once? Does wood off the back of a bow have the same effect as the same amount of wood off the belly?

[wizardgoat]

Don, id say if your about to brace it you probably don't want to touch the sapwood.  Dont worry so much if your bow limb has alot of sapwood, itll be just fine. If I thin my sapwood I do it before floor tiller, and I sand it and burnish it when I really start bending it

[Del the cat]

I'm just about ready to brace this bow I'm working on. On one limb(billets) the sapwood and heartwood are about the same thickness. If I decide to thin out the sapwood do I do it as part of the tillering process ( scrape the back instead of the belly)or do I try to go down a ring or two(or three) all at once? Does wood off the back of a bow have the same effect as the same amount of wood off the belly?

My first reply is still valid. I doesn't matter when you reduce it, it can be done in stages, but try to respect the rings where possible, but don't beat yourself up about it. Keep the back smooth and even.
Del

[Springbuck]

I don't have almost any experience with yew, but........

I do a lot of reduction where I am trying to keep thickness exactly consistent, or something, and here is how I do it.

Get your preferred scraper, and a black crayon. Scrape the tan/red rind off the yew where he bark was.  Then color the whole surface black.  Then scrape off all the black in one pass. Do it again. And again. And again.  If that's too slow, get a medium or fine rasp, color the surface black, and rasp off the crayon in one pass, then scrape the rasp marks smooth in one pass.

Might work.