Primitive Archer
Main Discussion Area => Bows => Topic started by: Gregoryv on January 22, 2020, 01:02:18 pm
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Ok question. Have any of you noticed that working a stave one way to the other when chasing a ring can cause tear outs? Could a bad bevel on my draw knife be causing this? My draw knife is a Witherby and the bevel is about 35 or 40 degrees. When I expose a layer of early wood in between two late wood rings and try to use the knife to wedge one ring off the other, the upper layer ends up tearing off the under layer I intend to use for backing. My knife tears thru the early crunchy wood, but then the wood splinters and “grabs” the lower ring. What am I doing wrong? I know I can use a scraper or a less aggressive approach, but I really want to master this technique. As I have seen a lot of tutorials on this, and the only difference is in the tutorials the splinter cause by the draw knife stays on the ring to be removed. Should I change the bevel on my knife?
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You can change the angle by tilting the draw knife. Are you using it bevel up or down? You'll have better control with the bevel down.
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Greg I'm curious what your edge looks like. From how you were discribing your sharpening problems it doesn't seem right to me. All my draw knives bevels continue right to the edge. I'm going to post some pictures of one of my draw knife edges.
Bjrogg
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I don't know if you can see what I'm saying. Pictures didn't turn out that great. Probably should have had a different background.
Bjrogg
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working a stave one way to the other
Can you explain this a little better?
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I'm a bit curious what you mean by wedging the wood off to. I might split it off above but when I get to one ring above I'm more like shaving it off. Leaving some crunchy early wood and using scrapper to clean it all up.
Bjrogg
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What starts as a peel turns into a small split then a tear. My knife has a much steeper bevel than yours. Probably twice as steep.
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Are you working bevel up or down?
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DC, I think he means working the stave in the opposite direction. At least that's what I thought he meant.
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Bevel down. Working from my layer that is the back toward the layer I am removing.
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Myself repeatedly and others keep telling you the same thing. Scrape the last ring off. Don't try to strip the wood off exposing your back ring, especially on green wood. I don't mean to be snarky but you have asked the same question 3 times. Either you don't believe the answers your getting or don't understand them. Your ok either way, I just want to know??? Turn the blade upright and shave it off. BJ just said the same a few inches up. Are you just not believing that to be sound advice, or have you read something (Video) and your not getting the results that were advertised and you are determined persevere? I'm not angry at all, just puzzled.
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I am sorry I am new and was concerned as to the bevel on my draw knife. So I asked a question in a forum and a lot of people helped. I am trying to do exactly what you stated. I can’t scrape the last ring if I cannot get to it cleanly. I was worried that maybe I should change the bevel on my draw knife or maybe get a new one. This hobby is new to me, but I am very passionate about it. If you aren’t going to try to help someone and just keep feeding them the same information over and over again than maybe you are wasting your time. Because it has done nothing but hurt my feelings. So I do not know if that makes you feel good, but it doesn’t me. I am either not getting something or something is wrong with my tools. Thank everyone who tried to help me, and anyone else I’m not sure why you even waste your time reading my post?
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I'm not trying to be unkind.... I will take it that you just simply dont understand and that is ok You ask how you can scrape a ring off when you cant get to it cleanly. Very simple, scrape until you are cleanly on it. If you have to scrape 3 rings off that way to get there, so be it. That is better than continuously tearing into the next ring by trying to "lift" the offending ring(s) off of your intended back.
1. Tear into a stave removing all the bark and sap wood present. Go at it helter skelter if you wish. Expose one continuous ring if possible. Any ring.
2. Identify which ring you wish to expose as your back and gently....gently...remove the wood above that ring. If tear outs are happening turn the blade upright and shave off all of the rest.
3. There is no 3.
Dont be so sensitive. The world will eat you up. I'm happy that your taking the time and show an interest in this, but so much of this is just doing it. You will get the hang of it.
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Maybe the problem is the difference between cut and scrape. By scraping we mean having the edge at 90° to the wood vertically and drag the drawknife along the wood. It scraped rather than cuts. Scraping will not lift a splinter. I wouldn't worry about the bevel angle. I'd be willing to bet that every-bodies bevel is slightly different. At your(and my)level of drawknifing I really doubt that the bevel angle makes much if any difference.
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Ok it was a lot of grinding but I got my draw knife bevel down more like in your pic bjrogg. Now it is working great. It is “cutting” instead of tearing the wood. Thank you very much for posting that pic for me. I am about half way thru my first stave with no tear outs at all. One more thing, when I am done should I come back and clean up my pin knots, or just leave one layer of growth over them?
Greg
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Your draw knife may be the problem. If it has a very flat bevel then it's really hard to run a ring. My brother gave me his new draw knife some years ago and for the life of me I couldn't chase a ring. So I went back to my grandfather's old draw knife which was rather old and well worn and I had no problem chasing that ring. It's blade is worn and somewhat rounded, not super sharp, but will chase the finest ring you can find...…...Art
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Leaving a layer or island around the pins is the same as ring violation. Scrape the wood off very carefully, I prefer a round nose card scraper for this work scrape 360 degrees around the knot.
It is the one with the rounded nose in this picture to the right of the drawknife, these came as a set from Lowes.
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I would very carfully from every direction working towards the center of the pin knot and "lightly shave" off the extra rings.
It takes a bit just to get the knack of using a draw knife. It's a fantastic tool though once you master it. There are some woods that it won't work good on though. Elm is really bad at tearing out. Fortunately its a white wood and doesn't need a ring chased.
You might have some places on belly side that want to tear on you when reducing your stave. When I get reduced to floor tiller I usually switch to farriers rasp and scraper.
Bjrogg
PS I really don't think Slimbob was trying to make you upset. Sometimes it's hard to figure out exactly what is happening especially without pictures. It is a hobby that you will make mistakes. It is very humbling. Please understand that people will probably point out some problems with your work from time to time. Most of the time they really are trying to help you. Many times because we have made the same mistakes
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Gregory, if you are getting tear outs then use the knife with the bevel down and just find the right angle to use it.
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Work the islands around the knots and pins from the center out and around the pin or knot.
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Thank all of you very much for all of your help. My stave is down to one ring today. One good backing ring! Now to floor tiller. I was going to make a long flat bow. My last question is as per size. This is what I was going to go with and please correct me as you feel fit. 1 inch handle. 2 inch fades from handle. 1.5 inch at widest for limb out 3/4 of the limb. Then taper to 3/8 inch.
Or should I go 1.5 inch out of fades and taper to 3/8 straight from there? It’s my first bow. Which would be easier to roller?
Ps I should mark out the bow in pencil. Can I erase it from my back?
Thank you all very much,
Greg
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Go to 1/2" tips to start with, 3/8" is pretty small for a first bow. I start my taper about a foot from the tip on a layout and come back as the bow is reduced to a bow blank and take the transition point down to a gradual taper extending a little more toward the mid limb.
Do you have a tillering gizmo?
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Yes a pull string type but haven’t used it yet.
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Not what a gizmo is, it marks your limbs and tells you where to remove wood for a perfect bend.
There is complete how to make one and use it in the how to section of this site. The pictured one is a fancy one out of burl walnut, you can make one out of pine board that will work just as well.
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Ok tyvm!
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I know those tillering gizmos have helped a lot of both new and old bowyers. I think it would be a good idea to make one and check out how to use it. At least until you get a eye for it.
Bjrogg
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PM me your address Gregory and I will send you a Gizmo, I always have a few extra around. I have some fancy ones made out of curly maple.