Primitive Archer
Main Discussion Area => Bows => Topic started by: kevinsmith5 on November 12, 2012, 11:12:50 am
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Hello! This is my first post here but not my first post to a traditional archery forum (I'm not sure how you all feel about other forums so I won't say which one). I've already made two red oak wide (3" at the fade) pyramids, a narrow (1 1/2" at the fade) hickory pyramid, and a red oak Mollegebat (all linen backed) now I'm looking to expand my horizons. I've got 4, 1-3/4"x 3/2" by 8' pieces of ipe, and 4 1-15/16"x3/4" by 8' pieces of quarter sawn hickory. I'm thinking plane down a piece of hickory to 1/8" and back a piece of the ipe. I'm wanting 69-70" tip to tip, shooting for 60 lbs at 28". Advice on a profile for the taper? Thickness of the ipe? Should I still back it with linen (I actually like the way the black linen I've been using looks).
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Welcome to PA... ;) I'm not much of a glue guy,but someone else will come along n answer your questions. Okay..a lil advice..you shouldn't have to back the hickory if its already expectable grain for hickory. The only reason you wood put linen on it is for aesthetics.
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No reason to back hickory, unless it's horribly violated. Hickory is the best backing material, IMHO. Hickory/ipe pyramid bow will easily fulfill your wish list. 1.5 - 1.75" at the fades, tapering to 0.5" tips. For glue up, I use TB3. Make sure your surfaces are flat, perfectly matching, and clean. The contrast of ipe and hickory makes a terrific looking bow.
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Unlike adb's suggestion I would go no wider than 1 1/2" and preferably 1 3/8" or 1 1/4" wide at the fades. If you go too wide with the ipe it will be thinner than the backing when you are done(don't ask how I know! ;D ).
It would be a shame to loose so much hickory by planing it down to 1/8". Can you resaw it or find someone that can resaw it to 3/16"? Aftewr removing the saw marks you will have a backing of about 1/8" or slightly less, just right for hickory backing. If not, try this method I read about in an older wood bow building book I have...
Glue a piece of the 3/4" ipe to both sides of the 3/4" hickory backing. When the glue is cured saw the hickory in half, lengthwise so you now have 2 hickory backed ipe boards. Now you can cut out the shape of your bow, sand the backing smooth and start tillering.
Make the bow 1 3/8" wide out about 6" to 8" from the fades then taper to 1/2" tips for now. You can reduce the tip width to 3/8" after you are sure the string lines up well after first bracing.
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1 1/4" is all the width you will need with epe, by the time your all done it'll be close to 1 1/8" and you'll easy get 60# @28", i like patb's idea about gluing it up and ripping it on a tablesaw, a great idea, it dont take much epe to make a heavy bow, go parallel til about 10" from the tips and taper to 1/2" to start, Bub
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I was already planning to resaw it on my band saw, but I was still going to have plane it to get 1/8". I was also thinking about putting some reflex in during the glue up, so the double sided glue up might not work. :)
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I've seen some people say to shape and floor tiller the Ipe before gluing the backing on, others don't seem to do this. Seems like for some a glue up is like making an artificial stave with the properties of something like yew. Are both approaches reasonable and its just a matter of preference?
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I'm not sure why you would want to shape the ipe, floor tiller it, then glue a backing on and have to shape that again anyway. I would just do the glue up first and shape both layers at the same time.
Despite what some may tell you, there is nothing shameful or artificial to glueing up multiple laminations for a wood bow. Glue-ups just expand your options, allowing you to use sub-standard wood that would otherwise be used in a far less dignified fashion ;) It also allows you to use up those cut off pieces that would be too thin to make a bow on their own.
Edited to fix typo, because I'm OCD like that :)
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Despite what some may tell you, there is nothing shameful or artificial to glueing up multiple laminations for a wood bow. Glue-ups just expand your options, allowing you to use sub-standard wood that would otherwise be used in a far less dignified fashion ;) It also allows you to use up those cut off pieces that would be to thin to make a bow on their own.
Cam's right, i've made three or four 3 pc takedowns that the limbs were all belly cuts from pyramid bows, Bub
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I'm not sure why you would want to shape the ipe, floor tiller it, then glue a backing on and have to shape that again anyway. I would just do the glue up first and shape both layers at the same time.
Despite what some may tell you, there is nothing shameful or artificial to glueing up multiple laminations for a wood bow. Glue-ups just expand your options, allowing you to use sub-standard wood that would otherwise be used in a far less dignified fashion ;) It also allows you to use up those cut off pieces that would be too thin to make a bow on their own.
Edited to fix typo, because I'm OCD like that :)
+1
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Well, that ended badly. Had it at a low brace (3") and drawn to 26" when "boom". It looks like it started in the backing, cracked at the edge and went across....I've already cut the riser off and started gluing up another. I think the backing was too thick and had shifted too much stress to the back, so this one I've planed and sanded the backing to an 1/8". I will probably also back this one with linen after I cut the belly profile and before I tiller. This was the first bow I didn't linen back and the first one I broke...plus the Ipe is decking wood and the hickory was from flooring, so all I'm out is time.
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The back does look pretty thick. I like about an eighth unless I am making a really light bow for a youth or kid, then I might use closer to a sixteenth because of the overall limb thickness. I can't tell how straight the grain is on your hickory. If it is really straight, you shouldn't need linen. I would still recommend rounding the edges and sanding the back pretty good before you pull it too far, though.
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Yikes, sorry.
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The backing is indeed somewhat thick, but that's not the reason it broke. You can probably blame the break on bad grain in the hickory. Hickory should never break like that; a clean snap without splinters. Use a new board for your next attemps, and use this hickory board only for cores, bellies and handles.
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Grain run out + sharp corners=kaboom. Radius ALL edges before doing any serious bending
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The first thing I do before starting to tiller the belly, is to round all back edges. If you leave the edges square, all the bending stress is concentrated on the edge. Hickory / ipe should be bomb proof. Without any pics, it's also possible your tiller was off, with a hinge at the fade where it broke.
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It wasn't hinged, I was using a filleting gizmo and was down to thinning the tips. I hadn't rounded the edges yet, but this was my first attempt at a working back. You live, you learn, you break bows...
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Yup... live and learn from mistakes! Been there. Next time, round off those corners before you start making it bend! I used to have a bucket in the corner of my shop called the 'barrel of shame.' Used to put the mess-ups there in plain sight as a reminder not to repeat past mistakes!