Primitive Archer
Main Discussion Area => Bows => Topic started by: islandpiper on November 18, 2008, 11:35:37 pm
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No place on the web is there a group of guys who are more concerned with "doing what the wood wants to do" than you all here on PA.
Well, try this one of for size. A method of putting recurves in limb ends that is easy, painless, safe as any other, and re-do-able.
I made a red oak bow over the weekend and today decided to recurve the tips. So, I clamped down the tip, back side down with the remainder of the bow hanging out in space. I put another steel clamp on the other tip..........so, the bow was canteleverd out across the shop, clamped down at one extreme tip and with a weight on the other end.
Then, I poured a cup of coffee, got out the water spray bottle and the heat gun, and began heating and dampening and sipping coffee.
When the first six inches or so were hot, the bow just sagged down to the floor. A short wait and the clamps came off. Wow.......a recurved limb. Repeat on the other end and I had a recurved bow.
No muss, no fuss, no boiling liquids, no cusswords.
Just for the fun of it, i did that to the half a n osage bow i had left from last weeks explosion.......and it bent even easier. A little propeller bent in. I wasn't watching.....could have twisted it out but i had coffee in that hand.
piper
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looks like you found a method that works, might be able to come by tomorrow, you gonna be there at 5 pm?
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Thats pretty much how I do it but you do have to be careful of splinters lifting on the belly side facing you. If you can have one solid growth ring in the bending area it hepls and in the case of a board bow at least no run offs, otherwise use a pressure strip to hold the grain down and keep the bend nice and smooth.
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Ian, I'll be there until five.....not much after. I'll show you the red oak recurve that was made out of a stave you left in my truck last week........looked like scrap, right up till it started looking like a bow.
piper
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I'll bring by a correct arrow shaft for the spine tester too
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Here are some pics of the oak bow I made last week at the Renaissance Festival. Came into the shop on Tuesday and got the notion that it should have some recurve:
(http://www.forumpictureprocessor.com/pictureprocessor/images/DSCF0020_11.jpg)
(http://www.forumpictureprocessor.com/pictureprocessor/images/DSCF0021_13.jpg)
(http://www.forumpictureprocessor.com/pictureprocessor/images/DSCF0023_13.jpg)
This gravity assisted method of bending tips seems to work OK, and goes with what the wood "wants" to do I guess.
Later that day I pulled a crack in the lower limb. So, I backed it with brown paper grocery bag. And then, pulled the same crack later in the day WITH IAN JOHNSON THERE TO WITNESS IT!!! Dang, now I can't even deny it.
So, I glued it again, and added some more backing. So far, so good. I'm going to work it down to a lighter weight and keep my fingers crossed (and my hard-hat on).
piper
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Well I'll be durned. I've read about the indians using wet moss and hot rocks to bend wood. I just wonder if the didn't slowly pour hot water over the wood while it bent? hmm.... You may have helped to unlock one of the ancient mystery's piper ;D.
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Piper, be carefull about trying to put too much weight and too much heat. Emphasis on too much heat. I ruined a good,almost finished hickory bow with too much heat with a weight on the end. Hickory is so tough that it will keep bending without coming apart. But the cells in the wood are destroyed.
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cowboy....yup, that's me, archery-anthropologist......says so right here on my card....uh....I must be out of them right now.
mullet, i had a four inch, deep reach C-clamp on it with a little auxilliary weight, centered so it would not propeller. It it had, I could swing the clamp to either side, or put on a lightweight bar clamp so it worked against the twist. This was just pretty much slow and easy. I read on an earlier post that about 144 degrees or so was the line when it came to bending temp, so every now and then I'd put my coffee cup down and wrap my hand around the hot part of the bow. Never really got to where I couldn't handle it. I straighten necks on some pretty valuable guitars with a hot-jig and use the same precision temperature sensor, my left hand. There we worry about inlays, veneers and vintage varnish and, trust me, a 1940 Martin D-28 is still more valuable than any bow I might be making.
I think one of the important things in all this is to "listen and feel" the wood. Don't just barge ahead and impose too much of your will on it.
piper
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Yep, that was me, Barging ahead. It would have been better if I was sipping coffee and not a beer. I didn't know about the high heat "cutoff" till I read Mark's thread also.
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Mullet, later that same day I did this to one half of the Osage board bow i broke a couple days before. Heated that up and, man, it bent like hot plastic!! and talk about PROPELLER!! Two guys with an old J-4 stopped in to see if I'd make them a prop!! Youch.
Next time, i'll proceed with more caution in Osage.
piper
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Good idea - used this method to add some reflex to a stave's "flat spot" this weekend - clamped about 4 inches from tip and put a vice grip on the other end for weight. was able to evenly add reflex similar to the other limb's. no cauls, clamps or" @#%$&^*$ 's" when the clamps slip!
thanks ;)
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I've used this"gravity" method for quite a while.It does work,and works fast.One word of caution,(because of a few "memorable occurences",which happened to "yours truly". It is much safer to set up a "stop",this way you can break down the process into stages to check the wood in the bend. Your right ,it will melt like butter,but it can go too far without the "stop",and break.I've ruined several staves in this way,or ,had to pike and re-plan.Just my 2 cents worth. God Bless
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There is even easier method. Just saw some kerfs. Fill up with wood and glue.
Bend.
Alternatively:
Just saw some kerfs. Heat. Fill up with wood and bend. Wait. Fill up with wood and glue.
bend again.
(Results are lower right corner:)
http://www.perinnejousi.fi/keskustelu/files/jannejousi_479.jpg
This is not a truly primitive method as it requires a saw. The example i usen bandsaw, but I assume hand saw is ok too.
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i believe i watched you pop one of them splinters. quit givin ian all the credit. >:(
lol. did work nicely though. you tried that heart pine for anything yet? DONT BANDSAW IT! it ruined my blade.
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Recurve: i can bandsaw that stuff all day.......difference in saws and blades.
I'm still playing with that splinter. I may glue it again and use that old favorite primitive material "dental floss" as a wrap to hold it all together and then just not do any more tillering adjustments at that spot. I know, I could make a new bow quicker, but the act of repair and saving this one is probably a good excercise.
piper
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oh, yeah. well, my saw is junk. :-\
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thata awesome piper, is it pretty accurate? from my experiece, even with a form i've had bad luck having both limbs bent the same- looks like it would work real well though- good post man. -jimmy
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I have that bow bending pretty nice for one made out of junk wood, in public, while answering questions, then splitting it twice and having to wrap it with dental floss. I have had it strung up a dozen times, pulled it as far as feels good and shown it off like a proud papa. So, I guess I should take some pics and post 'em here.
As for even-ness, i have spent a lot of time throught the years bending violin, viola, cello, dulcimer and mandolin sides, and didn't have any trouble making the ends of this bow bend the same. Now, the next stick could be different.....wood is wood.
But, the process runs slowly and without instant excitement, so more or less bend can be made and propeller pulled out of it as you go.
piper
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Had more success with this method today, piper thanx again. Got a little prop twist out just by torquing and clamping at an angle.
Love the craftsmanship in string instruments, but i'm only smart enough to be a drummer ;D Maybe you could post some of your musical work in "anything else"
After all, There's always room for cello.... ;D
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Good thread, Piper. I will try your method. I have used a similar method to get rid of a twist in a limb. I clamp the bow at the handle on a flat surface and let the twisted limb hang out over space with the twist facing up. Then I clamp an old Jorgensen wood clamp on the tip of the twisted limb and use it as a weight to pull down the twist. I then heat the limb slowly with a heat gun and watch until the twist is about 1 inch below where I want it and let it cool. It works every time. The limb is perfectly straight when it cools down.
Dan