Primitive Archer
Main Discussion Area => Bows => Topic started by: BigWapiti on September 11, 2014, 11:16:20 pm
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I'm working a Russian olive stave I cut a couple years ago. No idea how this wood will do. I'm working two bows of different styles. This one has a pretty bad bit of reflex about 10" from the tip. More than I want.
Should I keep tillering and hope it comes out? Or heat, steam or boil it to try to bend it out? I just worry about it losing strength.
Thoughts? Thanks
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I would reflex the other to match the one with reflex.
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Very good question! All depends on your level of craftmanship. I would keep it as simple as possible and just keep on tillering to see nice curves on both limbs. What is your target draw weight?
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Shooting going for 60#.
I'm strongly considering just continuing w the tiller. Trying to decide where to focus in removing wood. It could turn quick if I don't plan my scrapes at that bend. I think I'll try moving forward - but if there's any suggestions I'm all ears.
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Anything you do while tillering that changes the shape of the bow is damage to the bow. I would use some heat to maybe ballance the two out, reduce the reflex slightly on one side and maybe add a touch to the other. This is why cawls are so valuable they start you off with a ballanced stave.
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If it's just 10 inches from the tip, I would steam in a matching reflex on the other limb first. Doing so would make tillering a lot easier.
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Hrmm. Maybe you're right. I'll try to match them up a little. Just concerned I'll compromise strength w heat bending. No?
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We really need to make it clear what is the level of craftmanship our advises target: beginners, intermediates, or experts. Frankly, I'm no expert, but I believe I know enough to help beginners. :)
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I read that heat bending would make wood 10% weaker. But near tips it would not matter much.
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Do like badger said, bub
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You don't have any serious bends to make, I am not convinced that heat neding a little causes any loss of strength. If you were to make a 1/2 cawl and treat each limb individually you could easily put them into any shape you want.
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SCP- even if heat bending made it weaker, the stave would be balanced and any weakness would be compensated for in tillering(leaving it thicker to bend the same as the other limb) If you don't balance it out, tillering would just get exponentially more complicated . It would be very easy to misjudge the tiller and weaken the reflexed limb to make the tiller look right. I know that it could be tillered as is , but it wouldn't be of benefit to anyone , IMHO.
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Alright. Sounds like the majority rules. I'll bend each limb to an even match.
Now I can tiller, it's the heated bends I've not yet done. Dry or wet heat? If wet, steam or boil? I'm suspecting heat (maybe w some oil / bacon grease?)
Thanks folks.
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Tillering a bow is hard enough with even limbs.
Couldnt do without my cauls now. Makes life so much easier, especially considering they took about to make.
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Anything you do while tillering that changes the shape of the bow is damage to the bow. I would use some heat to maybe ballance the two out, reduce the reflex slightly on one side and maybe add a touch to the other. This is why cawls are so valuable they start you off with a ballanced stave.
+1
By way of further explanation.
If you tiller it to pull out the reflex then the danger is you have made that limb too weak.
If you leave the reflex then it should show slightly at full draw. E.G peculiarities in the stave should still be there at full draw. If it looks even at full draw then the reflex limb is flexing much more than the straight one and is thus too weak.
Easiest thing is to even out the two limbs before you tiller it.
Del
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Personally I would make them match. I would make the natural reflexed limb, your bottom limb. No matter what you decide. I don't know anything about the wood your using. Some woods will hold what you heat in and others will not. Just as some woods respond to heat better. Try to research the wood before you decide. The rule of thumb is dry wood, dry heat. Wet wood, wet heat. I just bent some Osage with dry heat. I coated the limb one day prior with olive oil and right before heating. If you heat one limb you must heat the other. My
Situation was similar and I did what badger said. I put some in one limb and took some out of the other. Worked great. Read as much as you can before you make your attempt. After you got her bent let it reclimatise before bending for a couple days... I usually wait two to three days
Jon
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I'd go with dry heat, make you're form /caul and go to town ;)
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Thanks for all the help everyone.
This is the first time I've tried Russian Olive and haven't heard much about it otherwise. It is and grows like a invasive weed here. Just doin my part to prevent it's spread. :)
The wood feels extremely strong but it's really light so I have my doubts.
I'm going to give a caul I made a year or so back a try - have yet to use it. Fun fun
Thx again for the he'p!
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it may even out some as you tiller,, but to even them as suggested is a positive suggestion,, if you tiller as is,, you can still get a good bow as well,,
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I don't find it particularly "primitive" to heat or steam bend bow limbs to a caul to even out their reflexes. I would rather find another stave to scrape. Most people here appear to be trying to get the most out of a stave they got. But I have several dozen staves waiting for me turn them into shootable staves. I guess all depends on what you wanna get out of a particular stave. I would rather have a shootable "bow" from a stave within several hours of "working out". ;) How about you?
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Anything you do while tillering that changes the shape of the bow is damage to the bow. I would use some heat to maybe ballance the two out, reduce the reflex slightly on one side and maybe add a touch to the other. This is why cawls are so valuable they start you off with a ballanced stave.
+1
By way of further explanation.
If you tiller it to pull out the reflex then the danger is you have made that limb too weak.
If you leave the reflex then it should show slightly at full draw. E.G peculiarities in the stave should still be there at full draw. If it looks even at full draw then the reflex limb is flexing much more than the straight one and is thus too weak.
Easiest thing is to even out the two limbs before you tiller it.
Del
If you want a bow that shoots for a while ...I'd head this advice :) ;).............IMHO
DBar
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If you leave the reflex then it should show slightly at full draw. E.G peculiarities in the stave should still be there at full draw. If it looks even at full draw then the reflex limb is flexing much more than the straight one and is thus too weak.
I would love to learn how to leave the original reflex to show slightly at full draw. Any examples?
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http://www.primitivearcher.com/smf/index.php?topic=48411.0
didn't have to go far, two topics down
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I don't find it particularly "primitive" to heat or steam bend bow limbs to a caul to even out their reflexes. I would rather find another stave to scrape. Most people here appear to be trying to get the most out of a stave they got. But I have several dozen staves waiting for me turn them into shootable staves. I guess all depends on what you wanna get out of a particular stave. I would rather have a shootable "bow" from a stave within several hours of "working out". ;) How about you?
So do you think heat manipulation wasn't used in earlier times?
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So do you think heat manipulation wasn't used in earlier times?
Have you seen a "primitive" caul for heat manipulation? All I have seen are pictures of Japanese ones probably for gluing up.
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Why do you need a caul for heat bending?
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I'm not real educated, but I can see them using a campfire and two trees that's close together to do some bending............... ??? But I think if you get to thinking to that point you are there... ;)
DBar
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I routinely flip the tips to reduce string follow. But I'm not even sure that is wise. I'm not even against making a caul to even out the uneven reflexes if I'm making a bow for sale or for competition. But I would rather just scrape away and figure out a way to make the tillering work for such a stave. I'm sure I have made many light weight bows that way. Maybe I should get rid of the idea of perfect looking tillering and learn the feel of well tillered bow from a stave with uneven reflexes.
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Would it be possible to use the mass principle on staves with uneven reflexes? Instead of trying to make the tillering symmetrical for both limbs, we can simply balance the stave to make sure same amount of wood is in each limb as soon as it is bending in a nice curve. Does this make any sense? Or, should the more reflexed limb be made a little lighter?
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Plenty of examples of flipped and recurved selfbows by native peoples I'm pretty sure they used some kind of heat for that
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Well, dang. Several attempts ended in failure.
Used bacon oil and dry heated the wood - first attempt, got it nice and hot on the belly, but not scorched - hot enough to feel heat through to the back - put it in my caul and let it sit overnight. Next morning, released it from the caul and it sprung right back to original shape........
Tried it again, this time with more heat (enough to scorch the belly and the bow was very hot to the touch)... put it in the caul, next morning pulled it out to find the back splintered.
I need to check my thinking - if a bow is seasoned and dry, dry heat seems as if counterproductive. Not enough oils in the wood at this point, is there? Can someone explain the reasoning behind the concept of dry wood = dry heat / wet wood = wet heat? Seems as if it should be the opposite. Just curious.
Thanks.
I'm not giving up on russian olive just yet - starting another, this time a D-bow (staying on the simple side until I'm sure). Its too perdy of a wood, and seems quite strong.
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I agree with Badger,, the full draw profile will show that the limb has reflex,, I usually put the reflexed limb at the top in a bow like this,, so if it is a bit weaker,, it gives the bow a positive tiller(even though it may not appear that way braced) ,, and if some of the reflex bends out in time(and it can),, it will usually still shoot ok,, I dont like when the bottom limb is weaker,,, sometimes it is prudent to keep the bending and heating to a minimum unless absolutely needed,,and remember you can do a little at a time,,, depending on your skill level,, :)