Primitive Archer
Main Discussion Area => Bows => Topic started by: barebo on January 04, 2021, 02:13:58 pm
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Made a beautiful Hickory backed Black Walnut bow - carefully tillered and bending nicely and shooting great and it developed chrysals after about 100 shots. Decided to try it again a second time and really thinned the 1/8" Hickory backing to not overpower the Walnut. Got it bending nicely to 26" and pulled it a fraction more and it blew about 4" from the fade and I have no clue as to why. So I took a 54" piece of Hickory I had and decided to make a "shorty" just because I wanted to do one without a backing. It has an inch of follow but is a sweet and snappy shooter and tough as nails (well ...almost!) 2 backed Walnut bows down - 1 Hickory intact.
So I had a really nice quarter sawn Hard Maple board that I got from a fellow member here and had a nice bamboo slat. I know it's not the best combination but thought it would be a light and snappy shooter IF it worked. 1-1/2" fades to 7/16" tips - 64"ntn. I thinned the bamboo to about 1/32" and trapped it severely leaving the Maple wide and rounding the edges carefully. Nice Zebrawood tip overlays and Black Limba handle over Maple. Got it bending in a nice even arc and it came in at 53#@28" and weighs 15.3 ounces. Intense early string tension. Served the new string this morning then I sanded with 220 then 320. Decided to use a light Pecan stain and started to wipe it on and lo and behold - fret on the top limb!!! I never saw it until the stain was on? No tick or snap or hint it wasn't going to be fine. I'm over 80 bows since starting in '99 which is surely less than a lot of you folks, but my stave bows never fail??? Backed boards and I just don't get along I guess??!!
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I have had a lot of issues with frets on boards as well. Most of my early bows where made from boards and I chalked the fretting up to beginners tillering, but I have also had frets form around small rolls in the grain on board bows. Some didn't seem to get worse, others I promptly retired.
Walnut and maple are generally susceptible to fretting imo. Can you tell if the back, the belly, or the glue caused the second bow to blow?
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I would say a fret is almost always an indication that the bow was stressed so something might have been off with the tiller or design. Did it take noticeable set in that area?
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I think boards are generally going to have a higher failure rate. It would be an interesting poll to see how much higher most think it is.
a few reasons, not in any particular order.
1. you cannot evaluate the living tree the board came from
2. you have no idea about how the log was handled, lumber dried etc.
3. in spite of good ring lines when selecting boards, there will still be unknowns about grain orientation.
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I find a lot of people don't compensate for pin knots, by leaving a little bump around the flaw. You can get away with it sometimes, other times instant fret.
I would suggest using a tropical hardwood like ipe, or bulletwood, when making bamboo backed bows, much more resilient than most domestic hardwoods.
If you still want to use local woods for backed bows, modify the design by making the bow a little wider and or longer
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I have three suggestions, in no particular order....
Osage. Osage. Osage.
No, seriously. At least til ya get a couple good shooters.
I agree with Willie too. Unless you make your own boards, you usually have no idea how it was cared for from stump to store. There's a huge difference between the expectations of general purpose or furniture grade wood and prime bow wood.
I once bought a big, clear, black walnut board from a woodworkers store. It looked perfect, but every bow I tried with that thing fretted right off the bat. If I want to make a walnut bow in the future, I have two nice trees growing out back. I'll cut them myself.
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I have made a bunch of bows from clear, clean Walnut saplings. Saplings have a very thick outer ring for the back. At least the ones I have used. Bullet proof if the stave is knot free. I heat treated the belly on that wood till it was not burnt, but close on a form to get reflex ,and protect the belly from fretting. Turned out some decent bows. Like Birch 2nd string bow wood, but can make a nice self bow in the 35 to 45 lbs range. Same with Birch.. I can see from working with Walnut a Hickory or Bamboo backing could easily over power the belly ,and cause fretting on either of those woods. Never worked that much with hard Maple, so I have no idea.
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Osage. Osage. Osage.
Some of us sometimes find it easy to forget that this wood doesn't grow cleanly in everyone's back yard.
I would endorse using the densest straight wood you can find.
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95% of my bows I ever made were board bows and I have had experience with them chrysaling. Most of the time they did came down to two reason. 1. They were either stressed due to asking too much from design or bad tillering. 2 the board had a bad ratio of early to late growth rings and were light.
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Underwater basket weaving without scuba is a bad choice! Maybe a hickory stave, wide and flat/thin, and over built would work. Btw, you have made many more bows than I have. Might try sinew or rawhide backing :BB. Get your confidence back! (lol)
Hawkdancer
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I've made a few hickory backed b.walnut bows. To get away with it you need to trap or crown the hickory. Thinning backings does not change the stretch resistance of the wood. Your walnut got crushed by the big bully you glued to the back :)
Bamboo backed maple is the same thing.....but almost worse! Boo is so resistant to stretch that you had better use a very good,dense,and elastic proven belly wood. Osage or ipe for me.
Now a maple back walnut bow would have been a much better choice :)
Lam bows are easier in some ways than stave bows BUT your wood choice and combos must be stop on.
Get some ash and maple for backing these non so great bellywoods or of course sinew is also a great option as it has low stretch resistance.
Frets in one spot tell us we messed up the tiller. Frets evenly distibuted everywhere show we tillered well but the wood choice was off and the belly is getting crushed.
Remember the see-saw only works with two children of similar weight :)
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I agree on the maple/walnut combination. I've made a maple back walnut bow in the past and the only issue was tiller related. I just glued up another and I will keep you posted on its progress.
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Thanks everyone for the replies! What stinks is getting a bow bending nicely on the tree (actually I use the rope and pulley system) and getting it braced and finding out the time and materials not to mention the hours were a bust. Funny thing is that I just wanted to try something different with the Maple and the Walnut was a request from someone.
I harvested a 6" Hard (sugar) Maple and made some very decent bows from it. Same with Hickory and Hop Hornbeam. My Red Oak board bows unbacked came out fine and my Hickory board bows did as well. I have some local milled Hickory that is clear and knot free and now I'm thinking a Hickory backed Hickory recurve? No more Walnut or Maple boards for me!!!
I'll try to get a pic or 2 of the Bamboo backed Maple I started this post about. I'll ask my wife to snap one at full draw and hope it doesn't blow and scare the wits out of her!
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When wood is cut for lumber it is stockpiled, not necessarily under ideal bow wood drying conditions, until it is convenient to saw up the lot into lumber. When we collect bow wood from the stump we split, seal and store so the wood can continue to dry to make it acceptable for bow building.
I have said before...there is a big difference in a red oak board and a red oak stave and the way it is processed off the stump is the main reason.
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Osage. Osage. Osage.
Some of us sometimes find it easy to forget that this wood doesn't grow cleanly in everyone's back yard.
I would endorse using the densest straight wood you can find.
Thank you for saying this.....I would use osage IF I could get it readily.....but I simply live too far north for osage and it is very expensive to buy.
I had a great run going of 10-15 bows that came in really nicely. All were boo backed maple or hickory and for over a year, all of them survived and have become excellent shooters......until the last month! I am not on a streak of four bows MADE EXACTLY LIKE the good ones that have all fretted after being finished and shot in. SO FRUSTRATING to put that much work into a bow and have it fret late in the process. As the OP mentioned, I was finishing a tri-lam yesterday and was final sanding and preparing to put the first coat of oil on it because I really liked the bow....was excited about it.....then, I shot it one last time before sealing it and it fretted way out on the lower limb in an area that is not bending at all and has never been bending? Zero idea why that happened. Its like a tiny thrust fault (I'm a geologist so that is how I'd describe it) that goes from the core lam into the belly lam. Just no idea at all how that happened :o
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I wouldn't ditch that bow yet. If it's not bending I would sand it down and layer a hard piece of wood on top of it.
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some woods are more challenging than others,,to recuce frustration and increase success,, maybe just straight hickory,,, or something that is more forgiving, I have made nice bows from hickory boards,, I did have failures with backed bows, the tiller has to be more exact,, i think your failures are more the challenging wood than what you are doing,, try to keep it simple at first,,,, like you said its heartbreaking to pu that much work in and have it fail,, thats why investing in a good osage stave might be worth it,,time spent ,, usually comes with a shooter ,, that will outlast most bows,,
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Board bows are 100% dependent on the care the log received from felling to dried planed lumber. Hardwood mills as a general rule supply wood workers and pallet makers, many hardwood mills also have an on site pallet company. They do not think twice about the handling of logs or lumber for our purposes. If you have a local mill, that deals with small orders, you can request to have a log cut the day it was felled to your specs and pay for all the lumber in the log. If not, then you are at the mercy of the distributor. I speak from first hand experience on the milling side that it is nothing to have a load of hardwood logs on the bunks for weeks or more waiting to be milled. They were off the ground but in the weather. For lumber purposes that is fine, for bows not so much. You cannot tell the difference in a finished board that was milled the day the log was cut and one that was milled weeks after sitting in the weather in a pile of logs, in fact one that is cut the day the tree is felled has a greater risk of Checking and warping than one that has been on deck for a while.
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I've never had a straight grained red oak board bow fail. No knots allowed no matter how small.
I've made lots of board bows. Jawge
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I've never had one fail either, but that's probably because I caught them all fretting before they could blow.
I have had way more bows fret than break. Over the four years I've been making bows I think I've broken or exploded two ERC bows/staves, three purpleheart or maple/purpleheart bows, one red oak with excessive early wood, and a wacky white oak character bow with awful tiller. I currently have only 4 finished bows without no detected frets including the one I completed just the other day.