Primitive Archer
Main Discussion Area => Bows => Topic started by: jeffp51 on February 04, 2015, 10:15:37 pm
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I have been working on a mountain maple stave 69"--but I don't really trust the back much. One limb has 3 bulbous knots on it and the other--well I went and dented the back because I forgot to pad my wrench when removing some twist during the heat treating. The dents aren't horribly and are mostly longitudinal--but it looks like I probably broke the fibers a little. I am considering three options and wanted your opinions:
1. Live life on the edge and leave it unbacked and see what happens.
2. Back with rawhide. If I do that, I think I would have to sand down the knots to get the rawhide to adhere--guaranteeing a violated back under the rawhide.
3. Back with sinew, working around the knots and leaving them intact. I do need practice with sinew, but I don't have tons, and this bow seems long for that kind of treatment. I would think about narrowing and/or shortening it with sinew.
What do the experts think?
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There's a way u can steam the dent out, I'd roll with it, it'll be hard to back those big blobs
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the last picture is after steaming out the dents. They used to be worse. The question is if ground-down blobs/knots will be safe with backing on them.
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If u didn't violate em they'll be fine, just tiller accordingly, obviously they're not gonna bend as much as the other wood
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I wouldn't grind the blobs and expect rawhide to save it, I tried that with a piece of yew that was more checks than yew. The checks were fine, and rawhide held the violated knots down for about 500 shots, then kerpow. Could have been my shoddy tillering as well...but I'm blaming the cluster of knots I totally violated
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At 69" i would leave it be. If it were 59" I would ask where the dents were, exactly, and maybe consider at least backing that section. Those knots are good character. You can't cut them off and back it. The dents don't really cut across the fibers of the back.
I'm not saying there is not a better way to deal with it but I would leave it, especially if it were the woods I generally work with.
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What Steve B said. +1. Josh
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I still have the one you traded me Jeff. I may just get busy on it!
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Okay, Option 2 is probably out. That leaves living on the edge or sinew. I already blew up a kids bow from this same log. I would like to avoid that if I can and if I can maintain the character, all the better.
Joe I would live to see what you can do with that stave I traded you for. I think it will make a bow, but it isn't the easiest wood to work. Enjoy the challenge
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You can't salvage every stave or stick Jeff, but you can save your sinew for a more deserving one. Just my .02. Josh
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If you sinew back it you shouldnt have problems if you violate the knots, I do it all the time, but only if it will be sinewed, dont try with rawhide.
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Sobering is a long process, I agree with gun doc and save it for a better stick.
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thanks for the advice. I have to keep telling myself--It's just a piece of wood. It is from the first log I cut, split, and seasoned myself, though, so I would really like it to work. Looks like I will be living on the edge, and if it works, it will look pretty cool If it doesn't---I just hope I don't loose an eye. ;)
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Safety glasses. Wounds heal. Just don't ruin and important parts
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Go for it as is. Half the elm I cut looks like that. Just don't expect too much of the stave. Maybe aim for a lower weight. 69" is a good bit to work with. The dents should be fine, unless you can actually see where the vise made like a tiny stairstep into the wood.
Looks l;ike a nightmare to sinew. Tiller carefully. You can do it.
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retaliative beginner here but i have made a few bows from maple, i think it should be fine. the knots worry me more than the dents do. just my 0.02cents
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It would be better if the knots were cut very squarely and the sharp edges rounded slightly.i now use caution when limbing with a chain saw not to cut the limbs to close to the trunk because a lot of times the branch will split deep into the back.i would try to clean up that knarly one with a file or something to try to get it a bit more uniform.good luck!
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pulling 40# @ 16" with a just tight tillering string. I am showing the tiller with the sides flipped in the last two pics. what do you think? The limb is 2 inches wide at the fades, for what it is worth.
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Rigfht fade is ok for now, get the rest of the limb caught up to it. The left limb is much stiffer from fade to tip. Looks like it needs attention about 6-7" past the fade. Id get a very low brace on it myself. Lots of things change when you start pulling inward and downward.
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PD, I will assume you are speaking of the final picture when you mention right and left, since one picture shows the bow from one side, and the other from the opposite side. But when I ran my tillering gizmo over it, it shows a stiff spot about 6-7" out the left side and the right limb stiffer from the middle to the ends. This stave will teach me plenty, I think. What I think will be the top limb is straight, but full of knobby knots. the bottom (left side in final pic) is clean but with a gentle curve to the right all the way out to the tip. after heat bending, the tips and the grip all line up pretty well. I will post more as the tillering progresses
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Ok, the kinks in the upper limb are confusing me some, and I appreciate all the eyes I can get. this is 45# @ 22" and nearly full brace height. Pic one is top on right (knobby side), and pic two is top left. Unbraced has not changed significantly from the original picture. It is harder, because I don't think it is sitting level on the tree in the second pic, and I have never got the hang of the mirror method.
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Either no one saw this, or no one has an opinion (rare on this site), but I could use some extra eyes. To me the top limb looks stiff under both protruding knots (@12" and 20"), and the bottom limb is stiff between the middle and final third. Am I seeing it right?
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The knot may be throwing off your eye. I can see what you are seeing, but the knot really does throw it off. What are you shooting for? It looks really good to me. Knots throw off the tiller, not only by eye, but because how hard they are. I would keep at it slowly.
The left limb in the last photo looks good to me until after the knot, and then the last bit of your limb looks stiff.
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Trust your straight edge 100% on this bow. Run your scraper on edge from fade to tip on each limb. If you see the gap narrow even a little, mark it and scrape it. That gap should be consistent from fade to say 6-8" short of the tip tops. For the record, your right side mid is flat. Left limb looks good.
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Chris you are talking about measuring while flexed, as in with a tillering gizmo, right?
Joe I am aiming for 45-50# @ 29" I have about 7 more inches to go.
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Maybe this helps.
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That makes it look like it needs a little work right out of the right fade.
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But isn't that the side that has a bit of natural deflex? I think it looks pretty darn good.
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Chris you are talking about measuring while flexed, as in with a tillering gizmo, right?
You can use a gizmo, I don't like them at all. A straight edge works better for ME.
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That makes it look like it needs a little work right out of the right fade.
Nope, leave that fade be. Get the center bending more and it will change how the rest bends.
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if you are worried about the dents, then just sinew wrap those areas,, you dont have to do the whole bow
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It broke while exercising the limb just shy of 22 inches. I never drew it past 46#. It broke just below the last knot cluster where it seemed to be stiffest. There was no warning, just a violent explosion and that was that. Didn't hit my head, but I was glad I had the safety glasses on all the same. I think either:
1. the stave was doomed from the start, or
2. it was too thin just shy of the knot causing stress that the wavy grain could not take. the kid bow from the same tree broke in almost the exact same way (diagonal fracture just below a knot).
I wonder if heat treating made the wood more brittle.
I have one more stave roughed out from this tree that is much cleaner, both on the back and knot-wise. It won't hurt to try again.
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Those knots forced you to violate the grain too much. The grain swirled around the knots and though you tried to follow it it wasnt enough. I bet with no knots you would have been fine.
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Dang Jeff, now I know what bow you were talking about. Well it won't be long and you can start on the yellar wood.
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I have made several maple bows and heattreating is difficult with maple, my suggestion. If you treat them slowly I have good results. If the heat is too hot and too deep the wood became brittel and chrysals or broke very fast.
Greetz
Cord
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Sugar Maple has its place in the self bow world. Good try Jeff. Sounds Danny has you hooked up with some no-fail wood!
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Jeff, you are doing well. You have done something I have yet to do, TWICE. I haven't pushed enough yet. You are pushing and learning. I am very impressed with your work. Explosions or not.
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As a rule, I won't heat treat a bow if there are lots of knots on the back. I want to lessen the strain on the back in those cases, or at least minimize the strain. I'm sold on the benefits of it, but this is one case where a little set might have saved it.
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If ya ain't breaking ya ain't making! Sorry about your loss, get after another!