Main Discussion Area > English Warbow
I really wanted a yew warbow anyway
ScottRoush:
;D Now I get to start on my yew bow because it just arrived this morning! It's Pacific yew and 74" long. I'd love initial opinions on the stave.. and that bothersome (for me) knot.
Sorry for the crap pictures...
Such tight growth rings? Is it even worth trying to chase a ring??
And is that the cambium on the sapwood? I don't see any rings....
WillS:
Sorry to hear about the Ipe bow. Looks like it might have been too dry? Hard to tell though.
Onto the interesting bit...
That knot may or may not be an issue. It has got a ring of black gunk around it which might be cause for concern, but it's not in a dangerous place within the stave and even though it's poking through the back you SHOULD be ok. However, you'll need to wait a bit to see how it looks as the bow starts to flex. Or, I suppose, if you're super worried about it, give it a dig and see if it just drops out once you start removing the black stuff. If it stays put and really won't budge, superglue. If it falls out, do what I said in the PM and stuff the hole with a good solid mix of epoxy and yew sawdust, or even a Dutch Plug - make a long dowel of offcut yew and push it all the way through the hole where the knot was, leaving a bit sticking out each end, then remove the excess.
Everybody you ask who knows their warbows will tell you to always chase a ring with Pacific yew, if you're aiming for something over 100# or so. The sapwood looks a bit too thick from the picture of the end grain, so you'll probably have to reduce it anyway, at which point take your time and get down to a single ring but do it in stages.
74" is just long enough to push a 32" draw with a heavy bow (what weight are you going for?) and it's also the absolute minimum length allowed in the EWBS.
At this point, what I'd be doing is marking a center line, and drawing out your front profile bearing in mind what I mentioned earlier about Pacific yew - go slightly wider than dimensions of Italian yew bows - 40mm should be perfect. You can find fairly rough dimensions in Secrets of The English Warbow, but you're basically after a long middle section staying around 40mm wide, almost right up to mid-limb. At that point you should taper to 22mm thick tips. Cut that shape out and use it as you're tillering, but bear in mind the final tip width should be around 12mm. The wider you can leave the tips to start with the better, in case it wants to twist as you're teaching it to bend.
Once you've got your front profile roughed out, reduce the sapwood. You'll have a better idea of the ratios once the front profile is roughed out, so you won't need to spend hours chasing an entire stave - just the bit you need! You then need to decide on a belly profile - avoid the D shape of Victorian bows and some of the Mary Rose bows, and go much squarer - a bit like a rectangle that has no edges.
WillS:
This is a fantastic thread for a build along by the way - his bows are really nice and it's very well explained and written. Lots of info on profiles, tapers, belly shapes and so on.
https://www.primitivearcher.com/smf/index.php/topic,863.0/nowap.html
ScottRoush:
Thanks for all the info. Once again.. I'm off on my measurements! That stave is 77 inches.. not 74.
Thanks for linking that thread.. I've been searching for something like that.
You bring up something that has me thinking.. you mentioned my wood being too dry. I heat my shop with a woodstove... and it's been bitterly cold for weeks. I've noticed that all my dust catching buckets and slack tub are evaporating at alarming rates. Nothing I can do about the ipe.. but I now have the yew to think about. It came from a guy in California that is going through an epic dry spell... so I'm hoping there shouldn't be that big of a moisture change for the wood..... but would it be better not to keep the stave in my shop when I'm not working on it?
Del the cat:
IMO you need to get that knot out, but without damaging the sapwood end of it (that's if it protrudes to the sapwood).
If it just goes in sideways ignore all following referenceds to sapwood.
If it is visible from the sapwood side you may be able to knock it out. Basically you need to clean out the black manky stuff round the knot, that's the problem stuff, the knot wood itself is prob harder than the parent wood, but the black manky stuff has no strength and will compress probably causing a pinch.
If you can't see the other end of the knot it begs the question. What happens inside the wood?
If it was me I'd drill down the belly side with a drill a good bit smaller than the knot without going through into the sapwood or the parent wood (e.g just drill in the knot itself). Pick away at the remaining knot collapsing it inwards, clean it all out to solid clean wood (doing it this way leaves the wood fibres intact where possible for maximum strength) Pack it with a fairly dry Yew dust/epoxy mix this will squeeze out the hole in the back and show you have got a good fill. Once hard, you can then drill out a good depth on the heartwood side and glue in a nicely matching Yew plug.
IMO That's the most solid sound way of repairing it. You could just do a plug, but it's easy to end up with a cavity if you are not careful.
If you follow my blog from here, you'll see a HUGE knot on the side of a bow successfully filled and plugged. It shows why you need to see what's going on inside the wood.
http://bowyersdiary.blogspot.co.uk/2012/01/mystery-knot.html
Hope this makes sense and is some help.
It may be advisable to go for a more modest draw weight say 90 or 100 rather than going too heavy.
Del
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