Primitive Archer
Main Discussion Area => Bows => Topic started by: cutty on January 09, 2020, 09:25:55 pm
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After you steam in recurve tips do you follow up later and heat to set?
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Yes .using a heat gun.i turn them dark brown on white wood bows .
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But be careful if you have steamed in very sharp curves, overdoing it with the gun can make it brittle and crack in the form if you are already near the limit of the wood, ive had this happen several times after a succesfull steam
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Once the wood is hot enough to bend and is then bent when it cools it is permanent. There is no need whatsoever to heat again afterwards. Remember you want to use the minimum amount of heat to get the recurves bent. Heat weakens wood.
I don't know where this 'method' gained creditability.
A 'static' recurve needs to be only 1/16th thicker than the thinnest part of the working limb to 'stay put'.
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Once the wood is hot enough to bend and is then bent when it cools it is permanent. There is no need whatsoever to heat again afterwards. Remember you want to use the minimum amount of heat to get the recurves bent. Heat weakens wood.
I don't know where this 'method' gained creditability.
A 'static' recurve needs to be only 1/16th thicker than the thinnest part of the working limb to 'stay put'.
I have had numerous recurves come out a bit when just boiling or steaming them. Not right after unclamping but during the tillering process. Since I started heating them with a heat gun a few days after boiling they all keep their curve. How do you explain this? This happens mostly with yew and white woods. Black locust and osage keep the initial curve pretty good.
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2 x, but not when I dry bend, or tempered the tips after the steam to a light brown. I prefer to do it that way, because it works best for me.
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With some woods(like hickory) I think it's necessary to set the correction but with others(like osage) not necessarily so. I like to have recurved area thicker(about 1/2") at the apex of the bend then narrow the tips to reduce the physical weight.
Also, if you decide to set the steamed wood with dry heat be sure the back is sealed well so the quick drying doesn't cause drying checks. I use shellac. I actually seal the back of any bow I build with shellac. through the tillering process. Even when steaming the shellac holds up to the heat and moisture.
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Set the curve. It’s the sensible thing to do. You can then also reduce the mass more. The Turks should have toasted their siyahs.
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After steaming in a bend what does more heat applied to it do? I dont understand the science behind it. When you steam bend wood you do not add moisture to it, it is quite the opposite so that would leave to question why set with dry heat?
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Higher temp is the only thing I've come up with.
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)Higher temp does more things to the wood.
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So you can get higher heat temps from a heat gun then from just steaming?
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Definitely when you compare to a typical wet steaming set-up.
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Surface temps will be 400+°f with a gun and 212°f with steam. Wood is a very good insulator so it drops pretty quick as you go in but "the more you got, the more you get" ;D
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Oh ok. Learn something new every day!