Primitive Archer
Main Discussion Area => Bows => Topic started by: Dazv on November 26, 2012, 05:16:05 pm
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Hi all
I've got my hands on lots of yew branch billets which have lots of compression wood in the sap wood. I know sinew backed bows made from compression of trees like pine and hemlock make great bows but what about compression wood in the sapwood of yew???
Thanks so much in advance
Darren.
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I'm not quite sure what you mean by compression wood... What I believe is that with Yew the sap wood is good under tension and the heart wood is incredible in compression. So sap wood back and heart wood belly.
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Do you mean the bottoms of the branches? I've heard that you want to use the tops of the branches for their tension strength but if you're gonna sinew it then I guess that makes sense, cant wait to see what the rest of you guys say, I've never tested either theory :) Yet! Still waiting to find that perfect piece of old growth fir to try
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Hi all
I've got my hands on lots of yew branch billets which have lots of compression wood in the sap wood. I know sinew backed bows made from compression of trees like pine and hemlock make great bows but what about compression wood in the sapwood of yew???
Thanks so much in advance
Darren.
I'm not sure I understand what you mean, either. Can you explain?
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I'm not quite sure what you mean by compression wood... What I believe is that with Yew the sap wood is good under tension and the heart wood is incredible in compression. So sap wood back and heart wood belly.
Compression wood forms in conifers on the underside of branches and trees that are leaning. If you do a google image search you will see what I'm talking about, it's amazing stuff.
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I've made good bows from the tension side and compression side. The tension side makes a better bow. But a bow from the compression side is a tad touchier, but will still make a good bow. Just go slow and excessively exercise the limbs, and you'll get a good useful bow.
-Pinecone
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Hi guys thanks for the replies what I'm asking is what is compression wood in the sapwood of yew like for making bows???.
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Compression wood forms in conifers you can see a difference in the wood, it's so strong in compression wil will try and post a link to google http://www.google.co.uk/search?hl=en&tbo=d&biw=320&bih=416&site=webhp&tbm=isch&sa=1&q=compression+wood&oq=compression+wood&gs_l=mobile-gws-serp.3..41l2j0j0i24l2.4148.5043.0.6293.4.4.0.0.0.0.280.784.1j0j3.4.0...0.0...1ac.1.olUf-_Z2g20#i=0
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Here is a compression wood pine bow. http://m.youtube.com/watch?v=7O4_f052syc
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The tension side usually has a tighter ring pattern.
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I'm not quite sure what you mean by compression wood... What I believe is that with Yew the sap wood is good under tension and the heart wood is incredible in compression. So sap wood back and heart wood belly.
Compression wood forms in conifers on the underside of branches and trees that are leaning. If you do a google image search you will see what I'm talking about, it's amazing stuff.
Aaahh, yes. I have heard of this. Don't know anything about it.
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the wood at the bottom of a branch will be stronger in compression , because it has grown, fighting against gravity, unlike a vertical stem. If you use the lower half of any branch of any species it will always be stronger in compression....the same for yew...I believe
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The tribes of northen europe who couldnt get hold of hard dense wood species, to make their bows, would often use compression birch and pine. The same applies to trees that grow leaning over, or trees constantly blown by wind from one direction. Compression wood grows on the opposotie side to the force of the wind or gravity. Supposedly very good bows can be made in this way, with lighter than usual bow woods
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I know exactly what you mean I have had a couple of Yew logs where there has been 'heart' wood spreading right out to the bark and also wood which is somewhere between sap and heart wood.
My personal Yew ELB is made from a piece where immediately under the bark was darkish wood, then beneath that a paler strip and eventually real heart wood. I roughed off the outermost dark layer and got down to the slightly paler band and used this as the back.
See pic here:-
http://bowyersdiary.blogspot.co.uk/search?q=what+the (http://bowyersdiary.blogspot.co.uk/search?q=what+the)
The bow turned out fine. As it wasn't the best bit of Yew in the world I heat tempered the belly, it has little set and shoots fine.
This post shows a similar piece I cut recently, it was a decent sized log and yet has poorly defined sapwood, whereas the skinny churchyard yew next to it is gorgeous!
You can see the branch 'in the tree' and it looks like it should be perfect :( .
http://bowyersdiary.blogspot.co.uk/2012/11/variability-of-yew.html (http://bowyersdiary.blogspot.co.uk/2012/11/variability-of-yew.html)
Bottom line any Yew is better than none, and is likely to be better than many white woods.
Del
Out of interest we were shooting at a 160 yard makeshift 'clout' flag at the weekend, a lot of the guys found they couldn't reach it and moved down to the 120 yard flag.
My 50#Yew from compression wood made it no prob.
I'll bet if you'd asked those guys how far their bows shot before we started they'd have all said 180 plus... >:D
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From what I've read, and seen, conifers put on lignin rich wood on the bottom side of horizontal branches. Compression wood. Hard woods put on cellulose rich wood on the upper side of horizontal branches. Tension wood. I have made Osage bows from from the topside of branches and it is stronger wood no doubt.
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This is very cool and interesting discussion. Was there something about this in one of the TBBs?
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From what I've read, and seen, conifers put on lignin rich wood on the bottom side of vertical branches. Compression wood. Hard woods put on cellulose rich wood on the upper side of vertical branches. Tension wood. I have made Osage bows from from the topside of branches and it is stronger wood no doubt.
I think you mean horizontal branches?
That's why I posted my link which shows an almost vertical branch with weird heart wood/sapwood.
I think the simplistic illustrations we often see in books are pretty poor and have often just been coppied endlessly without question.
E.G:- we've all seen the pic of the horizontal branch, where it tells you to use the upper face. Yeah?
... But in reality (with Yew), it's the upper face where the branches all sprout up from! So if you want to avoid knots, the lower face will be the clean one, and that will have the coarser rings and the compression wood. So what do you do? You look for a vertical branch like I did, and what do you find? The wood is still all weird... so much for simple theory.
Bottom line is, you don't know what it will look like inside until you cut it, and don't believe everything you read in the books.
Del
(Don't trust cats either!)
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Yep, horizontal. Been a long Monday. Not sure of anything on Yew. Never worked it. Bucket list kinda thing.
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you confused me there...as Del says you must mean horizontal branches,,,,you take compression wood and back it with tension wood ,,,then you make the most of the stresses trapped in the tree as it grew
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Thanks so much for all of the replies