Hazel warbow

[Lucasade]

So I've finally got a bit of time to crack on with this - it's all roughed out and I'm doing the final shaping before it goes on the tiller (which will be when I've built the tiller rig...). Am I right in thinking the ideal shape is an inflated square? And is there any advantage to slightly trapping the back?

Also one limb has a lot of reflex and the other is nearly flat, so I'm thinking it will make my life easier if I steam out some or all of the reflex before I start tillering. I will be heat treating further down the line.

Finally I'm aiming for 70-80# @30" with side nocks - do I need nock overlays during tillering or on the finished bow?

[WillS]

Trapping the back depends on the quality of the timber.  There are some that say all white woods need to be trapped (especially for heavy bows) but if the wood is good enough in compression it doesn't require it at all.  Bend tests will help you decide that, otherwise the best anybody else can do is guess and offer personal opinion.

Ideal shape is again whatever you think will suit that particular piece of hazel best.  There are "safe" cross sections such as a rounded back and flat belly, and a straightforward rectangle with the corners rounded, but you may well find that despite starting with a particular shape in mind, as you tiller and learn how the wood is behaving that will change before the bow is finished.  I've seen guys over in Scandinavia who make warbows almost exclusively with white woods use almost circular sections for hazel, ash, elm and other white wood bows up to about 140lb or so, as the timber they select can take that approach without failing. 

Helpful right?! 

I guess if you want to play it safe, and potentially have a slightly over-built and slower bow but a heavy working bow nonetheless, keep everything as flat as possible on the belly, keep the bow wider than usual and make sure the corners on the back of the bow are heavily rounded - perhaps not to the extent of trapping, but definitely knock the corners off and smooth it out.

Oh, and definitely don't shape the final 12" or so of each limb until it's well past brace height.  Otherwise you'll suddenly find yourself with all sorts of alignment issues, width issues and so on.  White woods are fussy, and you gotta let 'em be that way

[WillS]

Don't need nock overlays, no.  When I'm making bows with sidenocks I cut the tillering nocks on the side straight away into the bare wood, and leave them like that until the bow is finished.  Especially at 80lb or something, you're not going to have an issue.  You can actually leave the tips completely bare on the finished bow, with no horn at all.  The horn is only for soft woods like yew, which can be chewed up by a string. 

If you're feeling particularly confident, and the brace shape is looking really good and you're happy that the bow will finish without breaking (and there are no chrysals!) you can fit horn nocks to the bow once you're at brace height on the tiller. 

[Lucasade]

That's great Will thanks. I'm definitely playing it safe on this one! Maybe in 20 years I'll be in a position to re-tiler it 

One big thing I learnt from the bow I made for my boy is that the wood tells you what it wants to do during tillering, it came out a somewhat different shape than it started and what I envisioned it would do.

[meanewood]

Can't add to what Will said, he's spot on with those observations and advise! 

[Del the cat]

I'd go wide (40mm), flattish heat treated belly, trapped back.
That should minimise the chance of breakage or chrsals.
This post from my blog gives some idea of the cross section on the one I made.
http://bowyersdiary.blogspot.co.uk/2015/04/first-test-shots.html
Del

[stuckinthemud]

I heavily modified Del's design to make a 30# hazel longbow, it shoots really nicely and no crysals - cheers Del !

[Lucasade]

It's been roughed out to the dimensions on the Norwegian Warbows site for a 90#er - I figured if I'm aiming for about 70 this would give me plenty of wriggle room. It's helpful to see the profile picture - thank you.

[Lucasade]

Just out of interest, if I trap the back too much how will I know? Ideally before I end up with a tension break of course... 

[WillS]

That's why you probably shouldn't bother, until you know you have to.  It's a waste of energy if the wood doesn't need it, and at 80lb I'd say you almost certainly don't need to.

Make the bow as you would anyway, get the corners rounded and smoothed out, and if it starts showing set across the entire bow, you can ease the back corners off slightly more until you're happy.  Trying to make a white wood bow ready from the very beginning is a pretty good recipe for disaster.  You can do it with yew as it can take more abuse than most people can throw at it, but try it with white woods and they'll kick you in the teeth

I have a feeling you're probably twiddling your thumbs a bit, waiting for a proper tiller tree setup.  That's exactly when you make mistakes that you regret afterwards.  Put the bow away somewhere, and don't look at it again until the tillering tree is ready.

Go on.  Put it down.  Put... the bow... down....

And have a cup of tea.

[Lucasade]

It's been put away for the last six months! At the moment I'm just scraping down the drawknife marks and rounding off the corners. Once that's done it will definitely go away until the tillering rig is ready. I've got elm, elder, laburnum and yew to play with in the meantime!

I like to get all the possibilities right in my head before I pick up any tools, and the difference between what you've said and the profile Del had on his page is quite significant so there's lots of space for rumination. In particular I'm trying to get straight what the difference exactly means and when the right time to move towards one or the other is, so lots of different opinions is really useful for me.

[WillS]

That cross section on Dels page is really quite extreme, and something I'd personally consider only for very low quality timber.  Bear in mind that with good hazel you can get away with a flat back and rounded belly, much like a Yew bow.  Trapping to that extent may be necessary depending on what the wood starts to do, but I certainly wouldn't recommend it as a "normal" approach to normal hazel.

If you're really worried, taking off 1/8" from the edges of the back would be very safe.  Nowhere near enough to affect the bow's lifespan, and enough to have some contribution to reducing the ratio of tension/compression wood. 

Honestly though, a simple bend test with an offcut will tell you all you need to know.  All wood is different, so you have to be prepared to adjust each time.  Not saying you don't know that of course, but following one extreme example isn't always the best approach.

I can remember being told countless times that ash needs a trapped back and flat belly, over and over again and when I made that 140lb ash bow it has neither because I simply couldn't be bothered! 

[WillS]

I guess what I'm saying essentially is that you may well end up with a highly crowned and trapped back and flat belly, and that's fine, but to start there is possibly a bad move.  You can always remove wood from the edges if the bow needs it, but you can't put it back on if you discover you've over-done the trapping.

Start rectangular, adjust as the timber wants you to.  Or something flowery and vague like that

[Lucasade]

So the time to adjust is if it seems to be taking excessive set, or is that too late?

[WillS]

If you start getting set at brace height or before/just after, and the wood is dry as a bone and well seasoned trapping would be a very good idea.  If you're getting "normal" amounts of set (1-3") just at the 18", 20" mark then heat treating will do the job.