Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: ranger 3 on February 12, 2009, 09:02:00 AM
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How long does the wood have to dry after boiling tips before you can continue working on the stave? I am going to recurve the tips...Howard
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If your wood is already dry I would suggest not boiling the tips unless you can totally seal them from the moisture. As they dry they are likely to check.
Dry wood, dry heat...wet wood, wet heat!
I use a heat gun and oil. After bending I allow them to cool overnight before stressing them. Pat
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Brad Merkel uses boiling for extreme recurves, but I always liked dry heat on dry wood like Pat said. If you recurve the tips far they will break fibers on the outside of the curve. I recurve the tip while it is still thick - 5/8" or so - and rasp off the belly side where it separates. Go slow and "feel" the give in the wood as you heat it.
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For a big static bend, I like to boil. It's safer especially if you haven't done much heatgunning. I've never had any check on me. I really don't think they take up too much water anyway. Give it maybe a week to dry after boiling. It helps to shellac it and also, boil just the tips, not the working section.
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Here is a pic. of my jig, is a 2X 4 and the bend is about 7" so dry or boil
(http://i297.photobucket.com/albums/mm216/ranger500us/IMG_0834.jpg)
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Here are 3 pics of one form I use with dry heat(and oil). Note the thickness of the tips. When I first bend the tips I use the metal strap to support the belly side to help prevent splinters from lifting. Like Shaun said, I keep the tips thick then reduce them after bending. If I do get splinters I fill with super glue before reducing just in case I don't get them all rasped out. The other 2 pics show making alignment bends so I didn't use the metal strap.
(http://i5.photobucket.com/albums/y199/PatBNC/forDon002-2.jpg)
(http://i5.photobucket.com/albums/y199/PatBNC/forDon009-2.jpg)
(http://i5.photobucket.com/albums/y199/PatBNC/forDon010-2.jpg)
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The tips on this bow were also bent with dry heat (and oil) but on a different, more radical form.
(http://i5.photobucket.com/albums/y199/PatBNC/HPIM1590.jpg)
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What type of wood are you using Howard? Like John, I've never had any wood check from boiling or steaming. I usually wait a couple days after boiling before working the wood again. If at any time you lose some curve, just put it back in your form and set with dry heat (heat treat) this time. Here, your wood must be absolutely dry.
ART B
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It is Osage Art, nice bow and snaky arrows Pat...Howard
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Osage bends easy with heat!!!
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If'n I ever get the nerve up Pat, I'm going to shoot your "Ole Snakey" arrow!!! Quick as my draw weight is declining it shouldn't be much longer, hehe!
Yep, osage bends great using heat!
ART B
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Art, that arrow flew OK for about 10 yards but went haywire after that. I think the fletching is the culprit.
Howard, I gave the bottom arrow to Art and the second from the top with red fletching to Bernie Dunn. The arrow I gave to Bernie shoots very well. Gets lots of looks at the practice line too.
I traded that bow to a blacksmith friend for one of his hand forged knives. Pat
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Could some please explain where and how the oil is used?
Thanks,
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I use olive oil because that's what we have around. Any cooking oil will work. I just dip my finger in the oil and rub it liberally on the wood where I am going to heat.
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The oil is used to keep from burning the wood. I think it also helps with heat transfer (not letting it cool as fast).
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I don't heat or boil anymore.But to recurve the tips I've only done them on a molded when green.but what PAT said is 100% true.Dry wood dry heat,wet wood wet heat.I did both a good deal at one time but never had a checking problem.
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Thanks for the info guys!
Roy sent you a PM.
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That is a pretty mild recurve. I would use dry heat on that one myself. I think I sent you this pics but the form on left is what I would boil. The one on right, I would heatgun.
(http://residents.bowhunting.net/sticknstring/recurvejigs.jpg)
I have never used oil with a heatgun. Keep the gun moving and at least 4" away and you shouldn't scorch. Also, patience is the ultimate bowyer's tool. It would take me at least 10 and likely 15 minutes to bend each side of that recurve. Get into a zen mode, feel the warming, then the heating then the plasticity of the wood and then gently tighten your clamps. It takes a long time to warm an osage stave through to make all the wood plastic. It's when we heat unevenly that we start screwing up.
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This was just an experiment but it shows what happens with dry heat applied too fast to a radical curve. I'm not saying it can't be done because I actually could have salvaged even this botch job but boiling is safer and ultimately easier for me.
(http://residents.bowhunting.net/sticknstring/envcurve2.jpg)
See how the wood actually buckled on the sides? The belly was warmer than the back. It was also scorched, kind of intentionally. This was using the form in the pic above.
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Should I keep the limbs 5/8 or floor tiller it?
Howard
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It sure won't hurt any to get it bending some. I usually do before I heat bend. It just makes things a bit easier. You might take your tips them down to 1/2" or so thick. They won't need more than that when all is said and done. Have fun. Good luck.
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Here you go,
Boiled tips, dry Osage, no cracking.
(http://i257.photobucket.com/albums/hh216/quartermoonlongbows/IMG_0099.jpg)
Regards, Bert.
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Oops,
Meant to show these too (http://i257.photobucket.com/albums/hh216/quartermoonlongbows/IMG_0021.jpg) (http://i257.photobucket.com/albums/hh216/quartermoonlongbows/IMG_0020.jpg)
Bert
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Bert, I love that bow!!!
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Thanks Pat,
It is a Bamboo backed Osage bow I build for a customer, by far the coolest bow I build, ever!!!!
61# @ 28" and 62" ntn Buffalo(Bison) tip overlays.
Bert.
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Here it is after bending and the tips line up. It has 3 1/2" from the back. Now I need to narrow the tips and start tillering.
(http://i297.photobucket.com/albums/mm216/ranger500us/IMG_0839.jpg)
(http://i297.photobucket.com/albums/mm216/ranger500us/IMG_0837.jpg)
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Leave the tips wide and start tillering. You may need the extra width for final adjustments and they won't effect the tiller at all. Same with the handle!
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By the way....she looks good so far!!!
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Thanks
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Very nice Howard,
Go slow with the tillering, because of the early string weight the tendency is to make them too light.
Looking forward to seeing the finished product.
Take care.
Bert.
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Ok I have got the limbs bending but the limbs and getting thiner than the curves. Do I thin the curves or leave them thick?
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If the curves are working curves you need to thin them along with the limb so everything works together. If they are static curves leave them as they are and reduce the width later. I like my tips thicker so I can make them narrow to reduce physical weight without reducing the strength. You may be able to reduce the thickness later but none of this is necessary until the very end...if they are static curves. With static curves you have a fade area where the limb fades into the static curve. Be sure this transition area flows smoothly.
Did the working/static thing throw a monkey wrench into the works for you? I thought I'd keep it interesting. d;^)
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Yes it did, I really don't know if they are static or working curves. How can I know this?
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The curve of a static recurves stay rigid through the draw and act as levers as the bow is drawn. This is the type I prefer. Actually, I haven't built a working recurve.
The curve of a working recurve opens up as the bow is drawn. This type gives you more working limb, where as on the static recurve only the mid portion of the limb bends and the tips stay rigid or static.
Most glass recurves are working recurves. A few companies make statics but they aren't the norm.
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Ok it is going to be a static so I want to leave them thick right?
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Yep! For now, leave them thick and wide. With recurves especially, you may need the extra wood for adjustments later and they don't need to be finished until the tillering is done.
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Here it is braced at 4" and pulled to 45#s at 15" I have a ways to go shooting for 50@27
(http://i297.photobucket.com/albums/mm216/ranger500us/IMG_0845.jpg)
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Work in closer to the handle and out towards the curves. Like I said before you have a fade at the curves as well as at the handle and you want them to blend smoothly into the limb. Watch that spot on the left limb where is is bending most. Mark that spot and do not remove any wood from there until you get the wood around it bending more.
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OK I have a problem I have a splinter coming up where there is a pin not on the back of the limb, the handle is to the left. Should I go down to another ring or should I put super glue in it. I need help
(http://i297.photobucket.com/albums/mm216/ranger500us/IMG_0847.jpg)
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If you have room to go down to another ring, do so! Be sure to leave an "island" of wood around that knot and any other you come across. It looks like you violated the growth ring that is around the knot. It is a common mistake but should be avoided. When a tree puts out a limb it adds extra wood for support around that limb. That limb "collar" should be preserved for protection also when making wood bows. Remember the wood on the back is in tension and the least violation of a back ring can be fatal and especially in a highly stressed bow like a static recurve.
Later you can remove the "island" around the knot if you are careful not to violate the ring below it.
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Thanks Pat, I will go to another ring. Do you think it will lose a lot of weight on that limb?