[Warbow] Warbows and yew sapwood question

I can see that yew is the best wood for making warbows as the sapwood is a really good bow backing I know that many warbows were probs not backed but left without any backing at all. No sinew or rawhide or cloth. I have a semi finished yew bow but it has some knots in the back and I found it really hard to get a single growth ring. Chasing rings in sap was super hard. My question is does the yew back need to be perfect or not? If they made a ton for war, then they must have been produced fairly fast and not all of them would have had pristine backs.

is a yew self bow better than a hickory backed yew warbow?
 


Del the Cat

Well-known member
A Yew backing does not need to be a perfect ring. The "It's vital to follow a ring" thing comes from Osage where ring early/late growth is like cast iron and chalk and you need the solid ring.
There are plenty of examples on my Bowyers Diary blog. Here's one example where I had to cut through sapwood growth rings to deal with a weird dip.
You can follow the whole build from cutting the wood to finished 130# warbow.
Bowyer's Diary: Dealing with the Dip
The last question is too general, but I'd prefer a good clean natural yew backing, but I've made yew bows backed with Hickory, Bamboo and yew sapwood from a different piece of Yew. All work well, boo is the fastest backing, but you can't beat the look of a self yew bow.
Here's a pic of the first Yew ELB I made over 40 years ago, still shooting (70#) I had to dip down through about 8 rings else, I'd have had no heart wood.
Following a ring is an aim, not a 'must' .The trick is good light and doing a little at a time, get it oughed out to and even thickness and then slowly expand areas where it's a single ring. A light touch across the grain with a fine rasp or b'stard file will crumble off the white "chicken meat" wood exposing a slightly darker yellow of the next ring. I don't get it finished until the bow is almost complete, to a great extent it is cosmetic. The main thing is to have no nasty discontinuities.
Trawl through my blog... it's all there, warts and all.
Del
ELB back2.jpg
 


that there yew bow is very nice. Thank you very much dtc for providing me with a link to your blog I am sure It will be cool to read and learn from.
 


I read your blog and I read one article about getting a longbow to brace height. Now I myself have done with the long string tillering and have been trying to get it to a 3 inch brace, but string material keeps stretching on me. I've tried hemp and twine and nylon braid,cand even paracord, but it just stretches and won't even hold a brace of 3 inches. Have some bow string material comin in the mai, but problem is it won't get here for 2-4 weeks. Might get out to the Home Depot in town and get some PVC coated steel cable. I reckon that will be hard for the bow to stretch lol
 


Del the Cat

Well-known member
Yeah it's a big problem without a decent string material.
You can press on with a long string, but be sure to keep it as short as possible such that it will just slip on.
If you do that, the poundage and draw length* actually give a reasonable correlation to the braced figure.
(* e.g Just take the distance the slip on sting is pulling back to as the draw length)
Keep an eye on the tip deflection and once they are pulling back about 7-8" you should be able to get it braced. Making temporary nocks with stringer grooves is a help.
A 5 or 6" brace will hold better than a 3" (for reasons of geometry)
I've had that trouble several times, and I use an endless loop string with an alluminium loop to allow it to be wound round to adjust the length.
Good luck
Del
 


Yeah it's a big problem without a decent string material.
You can press on with a long string, but be sure to keep it as short as possible such that it will just slip on.
If you do that, the poundage and draw length* actually give a reasonable correlation to the braced figure.
(* e.g Just take the distance the slip on sting is pulling back to as the draw length)
Keep an eye on the tip deflection and once they are pulling back about 7-8" you should be able to get it braced. Making temporary nocks with stringer grooves is a help.
A 5 or 6" brace will hold better than a 3" (for reasons of geometry)
I've had that trouble several times, and I use an endless loop string with an alluminium loop to allow it to be wound round to adjust the length.
Good luck
Del

Thanks for for your help DTC. I may just get on with the long string then until the string material gets here in the mail.
 


WillS

New member
Nope, don't use a long string. Too much time on a long string and you'll get set and come in underweight. Once the bow is flexing evenly, lose the long string. You won't get an accurate tiller shape with it anyway, as the short string changes the angles.

If you've got hemp, use that. Redo the loops and make sure it's twisted with tension from the start. Like I said before, guys are using simple hemp strings on 170lb bows. It does not stretch, unless it's twisted badly or incorrectly.

- - - Updated - - -

And the bow string material you're waiting for won't work either. Again, as I mentioned previously Dacron will stretch FAR more than hemp, linen, paracord or fastflight. It honestly doesn't work.
 


Nope, don't use a long string. Too much time on a long string and you'll get set and come in underweight. Once the bow is flexing evenly, lose the long string. You won't get an accurate tiller shape with it anyway, as the short string changes the angles.

If you've got hemp, use that. Redo the loops and make sure it's twisted with tension from the start. Like I said before, guys are using simple hemp strings on 170lb bows. It does not stretch, unless it's twisted badly or incorrectly.

- - - Updated - - -

And the bow string material you're waiting for won't work either. Again, as I mentioned previously Dacron will stretch FAR more than hemp, linen, paracord or fastflight. It honestly doesn't work.


Hi again wills. Yeas I have ordered a custom string made of the fast flight material, it is going to be 14 strands. Making a warbow is massive challenge when compared to board bows and cedar bows. I am not sure if I have enough of the tip movement yet to risk putting on a full brace.
 


Just had a look at a picture of a tiller I did and when looking at the tips in there bending position and not in there natural position, I probably have about 3 inches of tip movement from the bow being straight. I am right in tillering the tips first. I'm tillering from tips out to about 12 inches into the limb.
 


WillS

New member
You're at the stage now where personal preference and experience plays a part. For me, with yew especially, I get the tips moving first, as you are doing.

I try and have an almost completely stiff middle section at brace, as this reduces set and (I think) increases performance somewhat. The other option is to evenly stress the entire bow - at all stages have the bow looking like an arc of a circle. This is more commonly practiced by beginners, as they are always looking for a simple, smooth curve. If you're happy leaving the middle stiff, go for that approach. If you were tillering a whitewood bow, you'd always want to be flexing the whole bow evenly from the start.

The middle will want to bend more the further you pull - part of the skill in tillering comes from predicting movement, rather than pulling and spotting areas that are bending too much, which can be too late.
 


You're at the stage now where personal preference and experience plays a part. For me, with yew especially, I get the tips moving first, as you are doing.

I try and have an almost completely stiff middle section at brace, as this reduces set and (I think) increases performance somewhat. The other option is to evenly stress the entire bow - at all stages have the bow looking like an arc of a circle. This is more commonly practiced by beginners, as they are always looking for a simple, smooth curve. If you're happy leaving the middle stiff, go for that approach. If you were tillering a whitewood bow, you'd always want to be flexing the whole bow evenly from the start.

The middle will want to bend more the further you pull - part of the skill in tillering comes from predicting movement, rather than pulling and spotting areas that are bending too much, which can be too late.

Well I'm kind of just doing the tips but I would prefer to do what is easier I think. I don't have your experience and expertise so I want to do it in the way that easiest and less risky to the bow. If it gets some set I don't mind a ton as this is my first real bow. I'll be good if it can draw to 30 in he's and be 90-100 pounds, and not look to rubbish either :)
 


WillS

New member
I'm no expert Jack. There's tonnes of stuff I don't know yet either, but the basics I can help with. Just focus on keeping the stresses even and the transitions smooth and you'll be fine.

By the way, can you pull 90lbs at 32"? Do you shoot heavy bows and this is your first attempt at making one, or will this be your first bow with a heavy draw weight?
 


I'm no expert Jack. There's tonnes of stuff I don't know yet either, but the basics I can help with. Just focus on keeping the stresses even and the transitions smooth and you'll be fine.

By the way, can you pull 90lbs at 32"? Do you shoot heavy bows and this is your first attempt at making one, or will this be your first bow with a heavy draw weight?
I have a wolf recurve that is 84 pounds at 30 inches. If this longbow was the same weight I'd be happy with that is I have a bunch of arrows made for the 84 pound bow. How do you mean by keeping transitions smooth? I would like to move one limb as it is a slight banana shape right bow. String doesn't move stealth down the middle but is a little offset.

i do wanna go and buy a heat gun or many equipment right now though.
 


Del the Cat

Well-known member
All you need is in my blog, the search engine on the blog (top left corner) actually works quite well.
You can follow through the complete build of many bows and see how the tiller progresses.
I tend to watch for the middle just flexing and then work outwards along the limbs, others start at the tips.
Regarding string line, leave the tips wide until the bow is 3/4 finished. This lets you shift the nocks to one edge or the other to help stop twist/sideways bend/ and to adjust the string line.
Biggest word of advice...
GO SLOW.
When in doubt stop!
You should always do at least twice as much thinking, looking, feeling and checking as you do removing wood.
Del
 


WillS

New member
By "transitions" I mean the areas of the bow profile that change. If you've followed basic warbow dimensions, you should have (and I know this confused you on PP a bit) three individual sections of bow - a long rectangle in the middle, a long slow-tapering triangle in the middle, and a short, very steeply tapered 9" long triangle at the tips. Each section needs to be smoothly blended into the next otherwise you may have areas that encourage failure.

Follow Del's advice/blog for straightening, he explains things superbly on his blog.
 


Finding this all so confusing. Most bows I've made are by eye and some basic dimensions. They and kinda primtive, but they all shoot pretty good all the same. Didn't know these warbows were so complicated to make. Scratching my head with all these draw force charts and what not. How did the the ancients mass produce these things I don't know. Some of the stuff on that blog is alien to me.

some of it has felt like making up a compound instead of a primtive bow.
 


WillS

New member
You appear to be falling into the classic trap of assuming our medieval ancestors were primitive cave dwellers! These guys had every bit of knowledge and skill and mathematics we do, they just didn't have computers...

A Warbow is a feat of engineering - you're taking a single piece of normal wood and asking it to bend almost in half under a strain of up to 200lbs. There's a reason the English were feared by an entire country, and there's a reason a well made yew Warbow will cost you close to a thousand pounds. They're not some bits of wood accidentally made to be a weapon by some dribbling caveman with bad teeth and a passion for dinosaur hunting.

Don't worry about draw force charts, or any of that stuff until you can make 100lb bows with relative ease. Everything else comes with time. Be patient, enjoy it and try to follow rough dimensions and guidelines until you get your eye in.
 


Ok, so tonight I got the bow to a 5 inch brace. Was lookin real nice with an almost perfect bend and en BANG, friggin crappy hemp string blew on me. Tf! Now this string I made was meant to have a 30 pound breaking strain. Maybe there was some kinda nick in the string I didn't seem but the hemp was pretty crap anyway as it had different thicknesses at different lengths.cwas craft sore rubbish.could have ruined my bow.

@wills, hey buddy where can I get the real paracord that does not stretch? The rubbish I got stretches like mad, but you are saying the real stuff does not.chow can I be sure I'm getting the real deal and it won't stretch? Are you in Europe or us?


Edit,,, I see you are in the uk.
 


We'll I went out and got the real deal paracord from a military surplus store. I made up a fixed loop and tested them both with over 100 pound of weight. Had loop 4 inches from nock and braced and only got 1 inch of brace heigh. You can see the stuff slowly stretch. So paracord isn't what is used then is it.
 


WillS

New member
You're either buying the wrong stuff, or messing up the loops/knots.

I use 550 paracord to brace my bows - I recently did it on a 105# bow, and I've used it on a 120# bow as well. It holds the bow at a good 7" brace, and I use it to measure for a proper bow string.
 


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