Author Topic: Advice required regarding some yew...  (Read 7930 times)

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Offline WillS

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Advice required regarding some yew...
« on: January 18, 2013, 10:03:58 am »
Hey guys,

I picked up this piece of English yew which looked stunning before I split it... but it has a really bad corkscrew twist down it's length.  It's 72" long, and about 4" wide.  I cannot work out how to get anything out of it, as the twist is so extreme that one end will just be all heartwood if I keep it as it is.  I have very little experience with steam-treating propellor twist, so probably wouldn't feel comfortable using steam to correct this - plus I just don't know how to cut a bow shape out of a piece like this anyway.

The other problem is that on the end that is twisted, the wood has split into a fork.  Running a string line down the back shows that a fairly clean profile could be made with a small amount of twist, but one tip would be smack in the middle of this fork, and the heartwood/sapwood does really odd things here.   

Any advice, or just info on what you would do with this would be great!  ideally I'd like to try and get an ELB type out of this.









This is the fork at the bottom.  Don't particularly want to chop off any extra length if avoidable?

blackhawk

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Re: Advice required regarding some yew...
« Reply #1 on: January 18, 2013, 10:37:29 am »
That doesn't look to awful and unworkable....if your not ready for it then set it aside and build your skills up more until your ready to tackle it. Layout is easy....just layout a bow along the back following the grain and twist...you don't layout a bow continuing straight thru the twist....like I said set it aside till your ready if it looks too daunting to you.

Offline PEARL DRUMS

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Re: Advice required regarding some yew...
« Reply #2 on: January 18, 2013, 10:37:57 am »
Since you dont really know how to continue? I say continue and start to learn so next time you run across a stave as such your not intimidated, but excited to make a bow. Dry heat will straighten it out, twist isnt a problem until the bbow unbraces itself.  Start building and go slow. Always consider what your doing and how it will effect the build in its later stages.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline WillS

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Re: Advice required regarding some yew...
« Reply #3 on: January 18, 2013, 11:15:01 am »
Cheers for the replies! I'm gonna give it a go, as there's nothing to lose!

Still not sure about laying out the bow though. 

Quote from: blackhawk
....just layout a bow along the back following the grain and twist...you don't layout a bow continuing straight thru the twist....

This doesn't quite make sense to me?  I can't figure out how to layout a bow profile without going through the twist?  You can only draw out a guideline onto the bark, and that can only be in one dimension.  When I come to cut it out, whether it's with an axe or planer etc, as the wood twists suddenly there will be too much sap or heartwood in the twisted portion right?  How do you get around that?

Offline Weylin

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Re: Advice required regarding some yew...
« Reply #4 on: January 18, 2013, 11:22:56 am »
What Blackhawk is saying is to draw the bow on the back so that it follows all the dips, snakes and twists. Unless the stave is perfectly straight you cant have a perfectly straight bow. So as you draw your center line it cant veer off the side of the bow just because the stave is twisting it has to follow the center of the stave which happens to have twisted off to the side. Try to imagine if you were able to magically wrestle the stave perfectly straight, then you drew out your bow and then your stave popped back into it's current twisted shape, that's how your layout should look. I hope my ramblings make sense, it's harder to describe than to show. If you do that then your heart/sap wood ratio should remain consistent throughout the bow.

Offline WillS

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Re: Advice required regarding some yew...
« Reply #5 on: January 18, 2013, 11:27:20 am »
I think that sorta makes sense, thanks!  The trouble with being inexperienced I guess is being able to visualise the layout in 3d.  I can't quite see it unfortunately! 

The stave is straight, front on.  It's only in perspective that you see any twist at all.  Drawing a centre line has to be done front on, so it will look straight.  Trouble is, the wood underneath it won't be square, it will propellor twist.  I still can't work out how to cut it out to ensure sapwood/heartwood ratio stays equal.

Frustrating!

Offline Del the cat

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Re: Advice required regarding some yew...
« Reply #6 on: January 18, 2013, 11:28:07 am »
+1 for what Blackhawk said.
Let the grain guide you, but you don't have to follow it slavishly.
I think laying out slightly diagonal and ignoring the twist will be fine.
Del
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Offline Del the cat

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Re: Advice required regarding some yew...
« Reply #7 on: January 18, 2013, 11:32:05 am »
If you chop away some of the twist from each edge at the ends, it will help you see it as straight and lay out a line.
Eg. Make it look like it would if you'd sawn it on a bandsaw.
(Dunno if the pic helps?)
Del
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Offline Will H

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Re: Advice required regarding some yew...
« Reply #8 on: January 18, 2013, 11:36:29 am »
What you gotta do first is establish a centerline. Scrape the bark off and follow one single longitudal grain. Once that is done layout your bow to the center line. Forget about it being straight for now as long as it follows the longitudal grain exactly. Then as you cut out the bow keep the sides square to the back along it's length. This means as the stave twists you have to be careful to keep the sides from cutting into the belly. Maybe leave the areas with the most twist a little wide for your initial cut then come back and true them up with the back while cutting to your line more closely. Hope this helps. Try not to over complicate it by visualizing it in 3D. Just follow the grain and do it as you would with a straight bow. When your done, build a caul and get a heat gun and some clamps. It's not as hard as you would think ;)
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Offline PEARL DRUMS

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Re: Advice required regarding some yew...
« Reply #9 on: January 18, 2013, 11:50:37 am »
Layout will be done with a pencil and steady hand, toss the rulers and meter sticks out for this. Nothing is straight or square on this stave.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline ionicmuffin

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Re: Advice required regarding some yew...
« Reply #10 on: January 18, 2013, 11:56:07 am »
+1 for pearls advice, you have no use for a strait edge. The only thing you may want to know is about how wide the limb should be. but that comes after the center line. I use a strait edge often because im working with boards often. I dont really use a strait edge for something that twists and dips and curves
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Offline Pat B

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Re: Advice required regarding some yew...
« Reply #11 on: January 18, 2013, 12:08:21 pm »
Is there enough wood to split it again, going through the center of the fork so each half has one section of the fork at the end?  At 4" across you should have enough.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline danny f

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Re: Advice required regarding some yew...
« Reply #12 on: January 18, 2013, 12:13:00 pm »
i have some yew seasoning  in the attic almost exactly like like that. that black centre line  (heartwood) on the belly of the bow would be good to follow as it runs perfectly with the grain you would just be working from the belly instead of the back,  just set the bow out as if that was the string going down the centre of the bow.  following it which ever way it twists, once you have the bow shape you want then start reducing and straightening. thats how i plan on doing it. but im far from an expert.

Offline WillS

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Re: Advice required regarding some yew...
« Reply #13 on: January 18, 2013, 12:35:57 pm »
All brilliant replies! I must have been blinded by frustration earlier! Reading through these again its very clear.  Thanks guys!

One final question - if i were to follow the black heartline on the belly (or close to it on the back) what do i do on the fork? I'm not hugely optimistic with splitting it again, as there are some knots to avoid, plus i split the other half again and it wandered around and rendered that piece hopeless apart from billets.  Do i follow one of the offshoots of the fork and heat straighten, or go straight down the middle of them both and hope the wood behaves itself?

blackhawk

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Re: Advice required regarding some yew...
« Reply #14 on: January 18, 2013, 12:37:29 pm »
When was this wood cut? IMHO if its not at least a year old I would set it aside...yew is the only wood that is just not worth quick drying...especially that piece..because it'll twist,warp,and deflex worse than it is now....and you'd have even a bigger mess to correct.