Primitive Archer
Main Discussion Area => Bows => Topic started by: NOMADIC PIRATE on June 27, 2007, 02:05:07 am
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I've never being succefull bending even the most moderate tip. even Osage cracked on me ::) ::)
I'm getting redy to flip the tips on this shorty I'm making, I'm not keen to use steeming because I'm always battling MC, I've heard of using a matal band with dry heat,...what do you think ?
Any secrets you like to share ?? ;D
Thanks
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Manny,
I've had almost Zero success bending wood with dry heat - and it's not because I haven't tried. That said I've only tried it on a few species of white wood - I know lots of folks who work osage swear by it. I think the moisture rap that steaming gets is fiction. Steam gets the wood so hot that I don't believe it is possible for any appreciable amount of moisture to accumulate within the wood. I usually steam bend wood in the evening and am back at tillering the next morning and have never had a problem. Now if you boil wood, that's a different story...
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That makes sense ;D
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That said, given your climate I'd probably give it an extra day just to be on the safe side ...
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Iam with Gordon on this. Steam fer my $ does not add moisture ta wood. Metal band is on belly of bow when ya make bend in a jig. Done lots over fires and work real good. I like steam though......................bob
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I have had good luck with dry heat and with steam. Use a heat gun on high and hold it about 4 inches from the wood. Keep moving it back and forth across the area you want to bend. After a few minutes of this the wood should bend with minimal effort. I like to clamp one side of the bend before heating. Then clamp the other after it is hot. I found with the guava I got from you, that it has to be super smooth before you put dry heat to it, or it will scorch. I don't see why the metal bands wont work with dry heat. But if you heat it well enough, it probably wont be necessary. Justin
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Manny, if the bow is not complete, try to give yourself an unviolated ring on the belly side when you make the bend, I have had some problems trying to bend the guava stav you sent me, steam seemed to work better on it, but osage will bend easily if it is hot enough, just don't push too hard till it is ready, osage will get very soft and bend easily. I make some pretty tight bends on osage without a support strip but they are safer to use. Steve
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I guess I'll venture into the steam bath :D.........one more question I already glued the overlays, will the heat even if not direct mess with the glue ?
Steve, to follow one ring on the belly of Guavas would probably drive me toinsanity, or at least take 10 years out of my life span ;D
Justin, that's how I've being doing it with the gun, still always got some cracks ::)
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I bend a lot of Osage and Hickory.With Osage I steam it first if it isn't over a couple of years old
and then use dry heat after that to tweak it or flip the tips.If it is over 2 years I just use dry heat.
If you steam old Osage it will check sometimes.I do usually leave the last 6/8 in. a little heavy if I plan on turning them ,sometimes I will get some pull ups or cracks but they will scrape out.On Hickory I haven't had much luck on the tips with dry heat but always use it to straighten and interduce back set with good success.I oil it first with cooking oil at least with Hickory.I tried steam with white wood and it always seems not to hold as well or go back in a day or 2 to where it was.
As far as glue and heat I use TB3 and have done a couple after putting on overlays and didn't
have a problem but I would guess you are taking a chance. :)
Pappy
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I grease it up. Heat it with a heat gun until it is too hot to touch and then bend it in my vice. Sometimes I need 2 or 3 sessions to get the reflex I want. Jawge
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Manny, For osage and some others I will place the tips in the form, attach the metal band oil up the wood and put the heat to it. I like it with the bow sticking up at about a 45deg angle. When it is hot enough, gravity will start pulling the bow down. I then pull it to the form and tie or clamp it down til tomorrow. I leave the tips slightly thicker and wider so if I do get splinters I can remove them as I shape the final tips. I haven't used steam or boiling for many years since I got my heat gun. Pat
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I do all my recurves with a metal band and a heat gun with no troubles. I also really really get the area hot. 10 minutes at 1000 degrees and any wood will bend like jelly. Elm hickory, yew, osage. Thats the woods I have done so far with this method.
SJM
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I'm with Gordon and Bob here. I bought a heat gun because I thought I could save time but once you add up the time of scraping all the oil-stained wood off... :P I know oily woods like Osage bend easily with dry heat but my experiments with Yew were horrific. I did recently correct a bend in the handle of some oceanspray with dry heat. It worked well. Oceanspray is very, very, Very sensitive to moisture so that's why I used the dry heat. I think a lot of it depends on the wood you use.
Steam is a very natural way to bend wood. Wood is more flexable when it has a higher moisture content. Steam rehydrates the surface of the wood (where most of the bending takes place) and heats the wood to the core leaving the stave extremely flexable. This moisture along the surface leaves very rapidly. After an overnight sit the wood acts like it's fully-seasoned.
J. D. Duff
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Thanks for the responses.
What is the process of using the metal band ??
....Do you think I got cracks because I kept the gun at the wood wile I was bending it ?? ...it just occured to me that it could be a mistake ::)
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In my infinite stubborness (hate to give up and move to a different sistem untill I at least figure out how to do it decently).....well I went ahead and tryed dry bending again, this time I coated the wood with olive oil, and used a thin peace of wood under the clamps, looks like it worked (can't tell for sure untill I'll take the clamps of) I can see How a metal band would be even more efficiant being a good heat conductor,...I'm off loking for a metal strip for my next limb ;D
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Manny.......the metal band dosent work so much as a heat conductor but more to keep the integrity of the belly wood so it dosen't crack er split. Ifn its not galvanized wrap it each time ya use it with waxpaper so u dont get rust stains on the wood ;D............bob
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No one says you have to do the bend all at once. Sometimes I need 2 or 3 tries at it. Jawge
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Good thinking George ;D
Well it didn't work I still pulled a splinter.
But the second limb with the metal band worked great ;D ;D, so I went back to the first and did a bit more bending a bit further down the limb, they look good now :D
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Manny, did you floor tiller before bending? It's easier to dry heat bend thinner wood. Jawge
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One other thing you can do is to kerf the tip, that way you are bending two slats half as thin. Once it is bent, you glue them back together, possibly inserting a thin wedge of wood to stiffen the tip.
The metal band is to hold down splinters on the belly side. It provides support for the wood and helps get a smooth bend as opposed to the wood "kinking" at one spot. People usually make a wooden jig, so the back rides along a piece of wood and the belly has the metal strap holding it together.
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Are you crazy Lenny ?? with my wood working skills, kerfing is way out of the question ::) ;D
Yeah that's what I did, I made a form for mild recurve/flip of the tips, and used a metal band, it worked GREAT !!!
George, this is ectually a piked bow,...looks like the metal band is the answer ;D ...at least so far ;D ;D