Primitive Archer
Main Discussion Area => English Warbow => Topic started by: WillS on April 21, 2015, 10:47:39 am
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Bit of a frustrating failure this one.
Stunning stave of English ash I harvested a year or two back, with some nice natural reflex as a result of using the edge grain on the back. Decided to crack on with it today, and in about half an hour I got a reasonably solid tiller out of it at around 100#.
Unfortunately when I took it off the wall to sand and finish it up, I noticed some HUGE chrysals along one limb. Not sure quite why as I think the tiller is fairly sound but any thoughts always welcome! The chrysals are only on the right limb in the tiller pic, exactly halfway along. It could simply be down to some pin knots in that area, or because I had to really force the thing to move to start with due to the reflex. Either way, I might scrap it, or try a Torges style bloom to see if I can save it.
Here's the full draw at around 98# @ 30"
(http://i1202.photobucket.com/albums/bb363/Will_Sherman/received_10155472568360646_0000002454_2_zps2yjd6ruq.jpg) (http://s1202.photobucket.com/user/Will_Sherman/media/received_10155472568360646_0000002454_2_zps2yjd6ruq.jpg.html)
And the largest of the chrysals, with the pin knot it started from visible at the top of the pic.
(http://i1202.photobucket.com/albums/bb363/Will_Sherman/IMAG1697_1_zpsd90v7zzt.jpg) (http://s1202.photobucket.com/user/Will_Sherman/media/IMAG1697_1_zpsd90v7zzt.jpg.html)
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Pins and bad tiller do not mix well with Ash.
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Is the tiller bad?
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Scratch that - this says it all, really. Should have laid over an arc earlier.
(http://i1202.photobucket.com/albums/bb363/Will_Sherman/asd_zpstd6euvqx.jpg) (http://s1202.photobucket.com/user/Will_Sherman/media/asd_zpstd6euvqx.jpg.html)
I think the best solution is to heat treat that area, lay in a bloom and see if I can save it. Nothing lost, much to gain! The stave was an experiment anyway, and if I can learn to do a bloom as a result, it's all good.
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My opinion of Ash is well documented, and I'd never use it un-heat treated. (tosses imaginary locks and walks off) ;)
You have my commiserations I hate chrysals with a passion.
Del
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It's plenty heat treated! I've heat treated the belly three times before final draw length. I refuse to give up on ash, as I have tonnes of it and I know it can make superb bows up to 160# so until I get there I'm persevering :)
I'm looking forward to learning how to do a bloom now!
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teach a longbow noob what a bloom is. link to one?
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Is there any reason why you've flipped your tiller rig?
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It's only this way up cos of the RIDICULOUS initial reflex. It was completely impossible to have it the normal way up as it kept flipping on me. I had to hang it this way round, hold it in place while pulling to brace height initially, and then I didn't really want to put it back normal way round as I'd starting tillering by then. Any other time I'd do it normally.
Sometimes I'll flip a bow if I'm struggling to see what's happening, as well.
Jeff - a bloom is simply a chunk of wood glued into the belly of a bow. In this case for instance, I'll rasp out the entire chrysal area, right down to where it disappears (probably about 20mm deep judging by the size of it) and then cut a block of matching wood to fit the rasped area. The new bit gets rasped down until it's flush with the belly.
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Makes sense - thanks!
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Don't use a stave with too much reflex.
What does extra reflex mean to the bellywood? Remember wood can only compress/stretch about 1% of it's length.
And don't try to tiller a bow in half an hour. The result of rushing is that rather large weak area!!
As I seem to remember telling you ash is way stronger in tension than it is in compression. Equalise the forces and you will get much better bows.....however I also seem to remember you telling me that it doesn't matter ;) I've done a lot of testing with ash as it's our most common straight tree.....I'm 100% it does matter!
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I agree completely Mike - I'm not sure I remember saying it doesn't matter at any stage though! I rarely make anything out of ash without heavy trapping, heat treating and a flat belly. They all work, and provide consistent results, and if I need an ash bow I'll always use those techniques.
The reason this was frustrating for me is that I know having seen bows made by people like Jaro and Joe that ash also works without any of it, provided you're good enough to do it. Jaro's beautiful 160# ash self bow had no trapping, no heat treatment and a round Mary Rose style cross section. I've also seen a really nice ash bow that Joe made, around 80# which looked like a yew self bow except for the colour. It was completely round bellied and flat backed, very narrow and again had no heat treatment at all. The difference is that those guys are wizards with white woods. My hope is to get that right one day, and experimental stuff like this is the only way to get it right. I think also that the ash itself needs to be flawless for it to work, but my skills as a bowyer are way below par for it to work on the good stuff anyway!
As for the reflex - again you're quite right. It threw me for a loop being so extreme. The reason it had so much was because the stave was heavily bent sideways, so instead of doing awkward sideways heat bending which is always a pain with wide, thick staves I decided to flip the orientation and use the edge rings on the back of the bow, resulting in a reflex of about 5". We live and learn!
My next experiment is with ash that succumbed to the dieback disease. I've got about 6 dead straight 8ft trunks that would otherwise be perfect, except for a horrible black streak all the way through the cores. Those will be worked as usual - flat belly, trapped back, heat treated until the cows come home and if they work, I'll be trying the round belly, no heat method as well.
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If a stave has 5" of reflex I'd steam in straight and it will creep back to a more manageable amount. You can trap the back but using a small diameter stave does much the same thing. A thing that is also worth mentioning is that Czech ash is likely to be denser than ours. I've had a stave of Welsh ash that was .7 in SD but this is as good as I've seen but others have been far lighter.
Will, what was yours out of interest?
His seem to be around .8 as per normal when he harvests them from the right spot.
I wouldn't be too quick with a bloom though. They can shoot for good while with big frets - not very relaxing though!
BTW if you do go the bloom route you can boil the bloom and dry clamp it to get a really good fit. Leave it a while to dry and after a light sand glue it with TB3.
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Cheers Jeremy! I haven't actually measured the density of this stuff. I could do a test bit though. I remember him telling me ages ago how important it is, along with all kinds of very Jaro-esque ways of determining whether it's good or not, such as chewing on the wood fibres, and making note of the noise the stave makes when you slap it with your hand! He's the Willy Wonka of White Wood Weapons.
Liking the boiling idea - I do it with splices but never thought of trying it with a bloom. I've already chopped a chunk out of the belly, as learning to do it is more valuable to me than another sub-par ash bow! I'll have a go at boiling it tonight (while she's at work, of course ;) ) and see how it works out.
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Chewing the fibres, eh? Wouldn't fancy that with yew :) but I guess it would make sense one you'd tried a few and knew what you were 'looking' for.
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So my first attempt at doing a bloom was... Reasonably unsuccessful, shall we say. Lots learned however, which was the secondary goal!
Here's the bloom fitted.
(http://i1202.photobucket.com/albums/bb363/Will_Sherman/IMAG1710_zpscsgu6tnv.jpg) (http://s1202.photobucket.com/user/Will_Sherman/media/IMAG1710_zpscsgu6tnv.jpg.html)
The result was a complete failure, the bow exploded right in that area.
Lesson learned - making a very small patch in a weak area doesn't work, as the bow moves too much around it, and there's not enough solid wood to take that stress. Essentially I removed the chrysal, but created two more in its place.
I did get recommended by Jeremy to use a 12" long bloom, but by then I'd already glued the thing down!
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IMO patches need to be long and gently curved, same way as you would blend in any other feature.
Del
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Yep, definitely agree! The smaller and more abrupt things are, the more stress they take.
Trouble I have is that I've never had any sort of power tool - just a few rasps and drawknives. This makes long sweeping smooth curves very difficult to create, whereas with a belt sander or disc sander you could achieve that in seconds.
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Yep, definitely agree! The smaller and more abrupt things are, the more stress they take.
Trouble I have is that I've never had any sort of power tool - just a few rasps and drawknives. This makes long sweeping smooth curves very difficult to create, whereas with a belt sander or disc sander you could achieve that in seconds.
Yeah, I dithered for ages about should I get a cheapo belt sander (about £75)... eventually did.
It wasn't great, but with a bit of fettling and a good coarse belt (40 grit) it has been V useful.
Del
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I don't recall Jaroslav's Ash Bow but you all have to remember that it's not density that matters when making any bow, it's how elastic the wood is. I wouldn't bother making a warbow out of any Ash we have around here regardless of how dense it was because it's just not elastic enough. If it was all I had to work with I would definitely make the bow long. Heat-treating does not improve a wood's elasticity
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Good info as always Marc, thanks!
What's a reliable method for testing elasticity in bow woods? Is it as described in TBB - a simple bend test - or are there other, preferred methods?
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Yes just do some bend tests, check set.
Our ash must be significantly different because English ash can make some fantastic bows. I've had some of my test ash bows almost tied in knots - it's plenty 'elastic' ;)
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Yes just do some bend tests, check set.
Our ash must be significantly different because English ash can make some fantastic bows. I've had some of my test ash bows almost tied in knots - it's plenty 'elastic' ;)
What are we calling fantastic?
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Surely you are all talking about the same species of Ash and it's just individual variation of the tree that's giving the different results.
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If that bow were made from yew or elm it would have chrysaled, I see a slight problem in the tiller shape where it chrysaled but you should have been able to get by with it. Overall the bow is nicely tillered.
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what are the demension of that bow, length, width and thickness at the handle?
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It's been resigned to firewood now, so I'll have to go by memory, but I usually make all of my ash warbows using similar dimensions - 40mm x 35mm in the handle, and 82" long to start with, then piked once tillered. This one would have ended up being about 28mm thick at the handle I imagine.
As Jeremy said in this thread, it's quite possible to shoot them even with big chrysals, but I was more interested in learning how to make a bloom patch, so was quite willing to sacrifice a badly made ash bow if it meant learning something (which I think I did... make blooms longer!)