Primitive Archer
Main Discussion Area => Bows => Topic started by: dwardo on April 18, 2012, 01:00:50 pm
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Hi All,
I have a yew stave, 60ntn, 1.5 inch fades with a taper to the tips.
This is a very dense bit of wood and i am looking / hoping to get abotu 55lbs or a tad more if possible. I flipped the tips and have alow brace and 55 out to 16 inches.
Problem is due to it being relatively thin it is starting to take set already which is unusual for me at this stage. I am pretty sure its dry and i know i am pushing my luck length width stiff handle and tips but i was wondering what heat is like with yew? Set at the minute is about an inch and half and with any other white wood at this point i would have it braced into reflex and be happily heating the belly.
Problem is I have never used heat on yew before and i dont particulaly want to ruin the nice heart wood and sap wood colour. The other thing is this bow is mostly sapwood with a thin`ish heartwood belly.
The set is being taken evenly across the inner limbs and i have a fair old way to go yet, about 12 inches.
So whats your experience with heat and yew?
thanks.
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Hi, Dwardo. You may get different opinios here but I never heat treat yew. You may have braced the bow a bit too soon. I do use dry heat for correcting yew but I keep the heat gun moving and don't allow any color change to take place,
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Hi, Dwardo. You may get different opinios here but I never heat treat yew. You may have braced the bow a bit too soon. I do use dry heat for correcting yew but I keep the heat gun moving and don't allow any color change to take place,
I guess this was one of those questions that I knew the answer too but didnt want to hear it. Its a lumpy bit of wood with lots of character. I think as you say that i got carried away with its density in the hand then rushed the early brace, even though it looked ok it was too much.
Forgot that had a pic i took with my phone.
(http://i121.photobucket.com/albums/o218/dwardo/IMAG1205.jpg)
Could you not just lie to me? ;) Cheers Badger.
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I've heat bent Yew with bothe steam and dry heat successfully, I've also heat tempered the belly on a Yew longbow which I'd got to floor tillered stage. I clamped it up with abaout 1.5" reflex and heated the belly slow and steady wafting it about until I just got a slight darkening of the heart wood.
I protected the sapwood with a couple of layers of cloth duct tape wrapped slightly onto the sides.
Here's a copy of my heat treating notes, using a temperature controlled hot air gun from Screwfix (which I subsequently wrecked bu not leaving it nozzle up yo cool >:( )
Heat treating/bending temperatures. 27/3/11
250 for bending won’t scorch the wood, but it will brown it slightly when kept in with aluminium foil (Yew)… maybe 210-220 would be better (yes that’s safer , be carefull not to forget it and leave it cooking for an hour!).
I protect the sapwood back with masking tape and duct tape, rub a bit of beeswax on the belly to help spread the heat/stop scorching. 30/04/11
350-400 for heat treating. (anything over 250 will brown)
Currently using 310-330 on the Yew longbow I’m doing for myself, heating in a bit of reflex and tempering the belly all at once on the roughed out bow. Aiming for a fast 50 pounder which is what I’ve now got, 99% of the reflex has pulled out leaving a straight fast bow.
Hope it's some help
Del
PS Give it 3 days to re-aclimatize...
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Thanks Dell,
Notes are something I always mean to do and soon regret not making them.
Think it might be best to lighten the outer limbs a bunch and see if I can avoid any more set. Maybe set the handle back a bit? anyone?
Then if the set increases i think its going to get a gentle but long heating....
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Yew sapwood is generally pretty bad in compression. The heartwood can take a lot of compression, but the sapwood is only designed for tension, not compression. As soon as the sapwood is under compression, it will start to take set. It certainly won't necessarily break the bow, but set just starts to kick in. Since I don't see any heartwood in your bow (but I could be wrong), I guess this is the reason for your unexpected set. Try to keep the belly flat and the back crowned. That should keep compression on the belly low.
Due to the lower SG of sapwood, the bow can still perform real good. Don't let 2 or even 2½ inches of set scare you off!
I'm not sure how yew will take heat treating, so I'm following this thread :) But since I haven't seen or heard of any belly tempered yew bows, I'm slightly inclined to say that yew doesn't take it very well...
editted to modify typo.
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Yew sapwood is generally pretty bad in compression. The heartwood can take a lot of compression, but the sapwood is only designed for tension, not compression. As soon as the sapwood is under compression, it will start to take set. It certainly won't necessarily break the bow, but set just starts to kick in. Since I don't see any heartwood in your bow (but I could be wrong), I guess this is the reason for your unexpected set. Try to keep the belly flat and the back crowned. That should keep compression on the belly low.
Due to the lower SG of sapwood, the bow can still perform real good. Don't let 2 or even 2½ inches of set scare you off!
I'm not sure how yew will take heat treating, so I'm following this threat :) But since I haven't seen or heard of any belly tempered yew bows, I'm slightly inclined to say that yew doesn't take it very well...
Hmm. There is a relatively thin layer of heartwood coverign the whole belly which is flat`ish. Would have been nice to reduce the sapwood earlier on but with the lumpy bumpy back i whimped out ;)
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After seeing the picture I think I will change my response, I would heat trea the belly as described by Del, I believe Dark Sould nailed it with the sap wood characteristics. When I said I didn't get any color change when I heated I should have said I get a deepening of the wood grain color but no change from toasting.
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I've had mixed results heat tempering. It's worked well a few times and spectacularly poorly a couple of other times. Unfortunately I don't know the cause of the difference. Given those results, I don't risk it on good yew anymore.
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hello ive heat treated yew before,the way i did it was with a kettle of boiling water, steaming hot with towells and things to hold the steam around the area for bending ,also i had to tape the switch on cos i kept turning off lol.. the wood went very soft and bendy,i braced it left it for about two days,and it was fine,its up to yew,dont blame me if it fails though,i take no responsibility for your actions.
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looks like too much sapwood to make a decent bow to me.....without the heart wood on the belly yew isnt so special, in my opinion....explains the set
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hello ive heat treated yew before,the way i did it was with a kettle of boiling water, steaming hot with towells and things to hold the steam around the area for bending ,also i had to tape the switch on cos i kept turning off lol.. the wood went very soft and bendy,i braced it left it for about two days,and it was fine,its up to yew,dont blame me if it fails though,i take no responsibility for your actions.
That might be a bit dangerous ye mad man! >:D
My question was more aimed at tempering the belly rather than making it soft enough to bend.
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I've had mixed results heat tempering. It's worked well a few times and spectacularly poorly a couple of other times. Unfortunately I don't know the cause of the difference. Given those results, I don't risk it on good yew anymore.
Thanks Gordon, when you say "spectacularly poorly" do you mean damage or just no difference at all and just pulls out?
I tillered it out some more yesterday and its still at about and inch and a half of set, no follow due to the flipped tips yet. It feels so dense in the hand and has that dry "ring" to it so i can only guess its not too happy with compression so heat may be the only way to go..
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when you say "spectacularly poorly" do you mean damage or just no difference at all and just pulls out?
The belly would crack badly across the grain rendering the bow useless.
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when you say "spectacularly poorly" do you mean damage or just no difference at all and just pulls out?
The belly would crack badly across the grain rendering the bow useless.
Thanks for the info Gordon and i now see what you mean by "spectacularly poorly" :o
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Quick update.
Heat treated the bow over the weekend and started to play with it now its rested.
Well the same old results from every heat treat, brilliant as usual. Now its not a bow yet but the usual heat advantages were there. String follow gone, picked up quite a few lbs now removed and gave a little more "zing" is the best word i have now.
Braced here. Had it out to about 20 inches and still showing no follow. Bit more wood to remove yet to cure some flat spots and it bring it down to a managable poundage for me or it will never see any use.
Heat treat was about half hour per limb and as Del says only a slight colour change in the heartwood was as far as i went but made up for it in heating time and hopefuly depth of effect. Will keep you all posted once i get a few more inches our of her.
(http://i121.photobucket.com/albums/o218/dwardo/IMAG1343.jpg)
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Lookin' good :)
Del
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Bit more playing today and its out to 21 inch.
Its taking about half inch of set from flat so I am gonna got at it with the heat again tomorrow before taking out the last few flat spots, hopefuly getting out to 28 slowly.
Not a lot of heartwood left at all so if nawt else its an experiment in heat and yew sapwood.
(http://i121.photobucket.com/albums/o218/dwardo/IMAG0002.jpg)
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Yes another heat treat and at the same time hopefuly removing a bit of limb twist.
(http://i121.photobucket.com/albums/o218/dwardo/IMAG0011-3.jpg)
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Decided on yet another heat treat.
This is out to 27 inches and is about 55lbs. Shot her in about 20 or so arrows and its settling at flat. Shoots very hard and fast but it seems right on the edge so i expect it to take maybe an inch or so of set yet. The flipped tips should stave off the followif it does.
Just need to remove a buch of mass from the tips and check again. There are two knots in the top limb and a bucnh of bumps all over so we will see :)
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I've also had good luck heat treating yew. I've heat treated longbows and short, sinew-backed bows. I think it really improves the bow myself, but again I tend to use a "faster" heat treatment method, and I suspect this works on some woods better than others. I think heat treating would make a screaming bamboo backed yew bow, though.
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I've also had good luck heat treating yew. I've heat treated longbows and short, sinew-backed bows. I think it really improves the bow myself, but again I tend to use a "faster" heat treatment method, and I suspect this works on some woods better than others. I think heat treating would make a screaming bamboo backed yew bow, though.
It does seem to work well so far.
A few more bowyers eyes would not go a miss please as i just cant put this one to bed and finish it up :)
Out to 28 at 55 lbs. Its 60 ntn and lays flat on its belly, flipped tips up after a few minutes.
(http://i121.photobucket.com/albums/o218/dwardo/IMAG0002_COVER-1.jpg)
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Mods remove please mistake ::)
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Perfect. Its hard to see with those now popular circles drawn though.
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Sweet, you can see as it's coming back further the tiller is getting more circular.
Please send it to me for detailed analysis O:)
Del
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Sweet, you can see as it's coming back further the tiller is getting more circular.
Please send it to me for detailed analysis O:)
Del
Good stuff, think a few scrapes right in the top fade and I cant put off finishing it anymore. :o
I did the heat treat on this just as you suggested, with only a light colour change but prolonged time under the gun.
Perfect. Its hard to see with those now popular circles drawn though.
Cheers PD,
I know the circles can be off putting but i find they are handy as a second set of eyes. I find it pretty hard besides posting on here to get another opinion other than my own as i have never met another bowyer before, let along held another self bow or even seen on in the flesh!
Will get it finisehd up soon and the FD will be circle free ;)
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I was just giving you a hard time dwardo, no problems here. Your handle section is staying perfectly stiff. Thats going to be a great bow. I wouldnt mind finished dimesnions when your complete. I have a perfect yew log that was gifted to me and I have been collecting yew knowledge since last August. I want to treat it right.
What part of the world do you call home?
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I was just giving you a hard time dwardo, no problems here. Your handle section is staying perfectly stiff. Thats going to be a great bow. I wouldnt mind finished dimesnions when your complete. I have a perfect yew log that was gifted to me and I have been collecting yew knowledge since last August. I want to treat it right.
What part of the world do you call home?
I live near a place called Chester which is on the border between North Wales and England UK.
I have some very snakey yew staves to go at soon but they are taking an age to dry, much slower thatn their whitewood counterparts. I also have one that is very weak right at the handle so will be looking for ideas there.
I sometimes seemt o suffer from bowyers block, dont know why but it means i just cant finish a bow so this helps thanks.
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Looks very good to me,I would call that one done. Nice job. :) :)
Pappy
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Nice bow from that piece of wood!
I have tried heat treating quite a few times with English yew and my experience is that it helps no end. I've just made a 90# @ 30 English yew longbow that sits perfectly straight after a few hours shooting. I got it to about 20 inch or so just when it was starting to take a little set. Then heat treated to a light/medium brown and induced 1 inch of reflex as it had a roller coster lower limb and didn't feel like it needed any more.
Maybe the denser American yew doesn't benefit so much?
If i'm ever down your way it would be good to meet up. I'll bring a few bows for you to look at ;D
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Thanks Pappy.
Mike, yeah if your ever passing. Also have a friend with a woodland about 30 mins away so free access to camping and woooood ;)
The heat helped no end in this bit of wood. Without it i fear the braced weight would be poor due to the set. After a some scraping and sanding the colour change from the heat has vanished yet it has kept most of its shape.
I only even induced an inch or so reflex from flat which pulled out to flat in the last few inches of tiller.