Primitive Archer
Main Discussion Area => Bows => Topic started by: Lee Slikkers on August 13, 2011, 07:24:27 pm
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How long do folks typically wait to start tillering and working it on the tree after they have toasted a belly on a white wood (Hickory)
Many thanks~
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Lee I have never toasted the back of a bow I have heard is not good but I could be wrong. Usually after I lightly toast the belly I give my bows about three four days to re hydrate before doing any serious bending
Josh
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LOL, yeah...meant belly. I'll edit my post.
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Ya Lee I dont know how humid it is where you are but if its pretty dry I would leave it for a week, thats just me
Josh
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Lee, a week would be the safest time. I have stressed toasted bows after 3 or 4 days but I think that is pushing it.
ps. I edited the title of this post from back to belly! ;)
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Thanks Josh and thanks for editing my post Pat ;D
It just rained here all day...maybe if I put it upstairs by the slider screen door it would help some? Anyway, I'll wait more than I had planned (hate waiting but I guess I can work on another build)
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When I've heat-treated in the summer when it's humid I've started tillering in a day or two. I wait a week in winter, when it's drier. But keep in mind that I make light bows, up to 50 pounds at the most, so mine are under much less stress than those made by many here. I'd let it rest for a week just to be on the safe side.
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What if you (1) use boiling water for the heat source? (2) mist it with water? I haven't done heat bending yet. I used to make large format IPE carved signage. Sometimes after glue up the blanks would be warped the following morning. We would wet the blank and clamp it flat and let it dry overnight. It nearly alwayse worked. We were working with 2x6 lumber and put water into a spray bottle. Soaked the surface and reclamped it.
I wonder why a power steamer wouldn't work? I've seen steaming pans people have made for bow bending and I've seen guys trap the steam under foil over the stove to bend with.
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Thanks for the input and ideas guys!
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When you heat treat(temper) bow wood you are drying out the wood but also solidifying the oils and resins within the wood cells. This is where the extra compression strength comes from. If you use wet heat(steam or boiling) you are adding moisture to the wood. This works for bending but not for improving the compression qualities of the wood. After you add this moisture you will have to wait at least a week for the moisture to leave the wood or you will add set and make the bow mushy until it dries out again. If your wood is unprotected while it dries out again it will chech(drying cracks) as it dries.
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Just wanted to comment that this info is all good stuff, even for those of us that have done it a few times but have not mastered it yet. Thanks for the guidance Pat. Danny
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Thanks for this thread Lee.
Its good info for us new guys.
Especially since I've got two bows to "Toast" this next week... :)
-gus
PS. Could you send those rain clouds to Houston when you are done with 'em?
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I usually don't wait much longer than 24 hours before I resume tillering and have never had a problem - but maybe I've just been lucky so far...
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As long as Gordon admitted it, I will too! I wait 24-48 hours max and resume tillering as well.
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When you heat treat(temper) bow wood you are drying out the wood but also solidifying the oils and resins within the wood cells. This is where the extra compression strength comes from. If you use wet heat(steam or boiling) you are adding moisture to the wood. This works for bending but not for improving the compression qualities of the wood. After you add this moisture you will have to wait at least a week for the moisture to leave the wood or you will add set and make the bow mushy until it dries out again. If your wood is unprotected while it dries out again it will chech(drying cracks) as it dries.
I'm interested why you think that heat treatings increase in draw weight is down to the oil and resins being altered. These are inside the wood and are only present in small quantities. The material that is doing the compression work in a bow limb is pretty much just the wood at the bellies surface , not the wood under the surface.
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Mike As far as the resins and oils, " being in small quantities" I think it depends on the wood you are talking about as to the quantities. When you heat treat a bow properly you do it slow so it soaks deep into the wood is how I understand it so I would think the cells within are also being compressed, not just the surface. I will let Pat explain it him self as he knows allot more about the subject than I do. Maybe Marc st louis will chime in and give his spin on things too? He wrote a chapter in Tbb on heat treating.
Josh
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Love these threads, so many points of view and the benefits are of great value...thank you all
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Josh I understand what you are talking about. Take ipe as an example - absolutely full of resins yet when it's heat treated there is virtually no change in it's properties. Elm has virtually nothing in the way of oils in it yet excells when heat treated. Why does the belly become concave (starting flat) after treating? Something has to be 'leaving' the wood. If you get some resin and let it set it will become brittle and turn to powder when compressed. Also as I said before only the very surface of the belly is really 'working' so what happens inside the wood has no real effect on it's bending properties. If you get a chrysal anytime cut out the affected area and look at how deep the damage goes.
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Makes sense all good points Mike.
Josh