Primitive Archer
Main Discussion Area => Bows => Topic started by: kbuggie on April 15, 2019, 04:50:52 pm
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I've been building and breaking bow wood for less than a year now and need some help with final tillering advice, and fade and tip shaping.
This is the second pyramidal bow I've made from a 12 foot 2x10 of well aged white oak. Both bows have grain runoff in one limb, but when the first bow didn't break (I used fuberglass scrim as the backing), I decided to try another from the same board, but with deer rawhide, wider limbs (2 3/8" at fades) and slightly shorter (69.5" ntn) but I planned to give it to the friend who used to pull a 31" draw.
I've got the bow to 50# @28", and 58# @31" on the tiller tree. Weighs 692 grams. I've shot it about 150 times now at my draw around 27". Hasn't broken and lost all hand shock when I shaped and slimmed the tips.
Now my questions. I think I glued the deer rawhide upside down. I roughed it up, used TB 3, and its held tight to the bow, but it's got the fuzzy whitish side facing up. So I decided to try and use a scraper on the rawhide at the handle and I scraped through to the wood in no time. So I know not to do that on the limbs. So, I've slowly used a 180 grit to try to get the fuzz off for Tru oil. Is this the right approach? Sandpaper and patience? Just do it right side up next time?
Tillering advice. Sorry I don't think the pic is square as I pulled and snapped pic with other. Right limb seems stiff near limb tips.
Also, what tool should I use to get string grooves to curve more and not put angle in string where it leaves bow?
I also felt I was done with the fades and was going to only slightly round the handle before turmoil and paste wax, but then I read the comment on rounding the back of fades in Airkah's thread, and so I took about 80 grams of wood off the handle and fades last night. Much nicer feel after that. Thanks PA members in advance!
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Pic of grain runoff
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Repost of tiller at closer to 250kb quality. Sorry for bad pic quality.
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looks like you may have cut across the back of the bow when making the string grooves this is not good unless there's an overlay.
About the rawhide- I have done that before! I'm not sure how best to make it look smooth, but you could do another layer on top.
To round out the string grooves, start with a narrow sharp knife and finish with sandpaper rolled up.
Tiller looks good, given the profile. You could probably scrape the mid to outers on both, you have plenty of width for safety.
Fades are a bit abrupt where they feather into the limb.
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I agree with scraping a bit more through the mid limbs, to reduce a little bit of strain on the inner limbs.
The pyramid style might not be everyone's cup of tea, but I love the look. I also love the way it hooks at the end of the tips, not something you see everyday. I can't wait to see how it all turns out for you once its completely finished.
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DEFINITELY no more wood removal near the handle on both sides it bends far too much right next to the handle
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ok the rawhide is no problem,, just put desired finish on and sand,, and refinilsh,, repeat till you get the desired finish,, it will be fine,,
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Thanks to all for the replies.
On the tiller, I used my crude rendition of Mr. Krewson's gizmo, but I obviously struggled at the transition from fade to limb and limb to tip. I remember from his great you tube video he mentioned you have to estimate the proper bend in those areas.... still struggling with that.
With the tips, I went back and forth with what to do, but I thought it was okay for the string grooves to violate the back since my tips don't bend much. Fingers crossed. I do have a buffalo horn, and elk antler available for next time.
Thanks, Brad, for the advice on the rawhide!
The pic below is the prior handle and fade profile, and then another pic without temporary leather wrap and after shaping with my shinto rasp.
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Well done. That's what the tiller should look like on a pyramid bow...rounded. Jawge
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Looks comfy.
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I second what George said. The widest part gets the most Bend and stress. True oil will harden up the fuzzies and then they can be sanded lightly. Then add more true oil and repeat if needed. Your bow looks great.
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Thanks George, Knoll, and Sagebrush for the encouragement. I'm trying to work on all the advice everyone's given. Including giving tip overlays a try. I'm battling that "am I snatching defeat from the jaws of victory" feeling by messing with the tips. But then I decided that if I don't learn on this bow I'll be even more nervous on the next, especially if it's a purchased stave.
I'm lucky to live in the American southwest where I can walk down to numerous native American craft supply stores and choose this $20 bison horn from amongst a dozen such horns, and choose from a similar selection of deer rawhide ($90 for a good size buckskin).
I'll post pics when it's done.
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Tips are pretty low risk. Defeat shall not be snatched from the jaws of victory today. You got this!
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I got the tip overlays added to the bow. I used Gorilla glue gel super glue, and sized the oak with regular (less viscous) super glue,10 minutes prior to gluing with 4 drops of the gel glue over the 1.75" contact area. Then I clamped each tip with 2 really small clamps
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Glue line looks great.
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I kept working on everyone's suggestions. I feathered the fades more, rounded all corners, glued bison horn tip overlays on, and tried to curve the string grooves more to ease the string angle. What I thought would be the upper/lower limbs was wrong as the bow shot Rose city 11/32 40-45# arrows much better "upside down." So I ended up putting bison arrow passes on both sides so the bow could be shot with either limb up or down. Thx for all the help on this one!
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Prior post is past tense because the bow cracked in the 'lower' fade during the final shooting session before adding tru oil. Cracked along an early growth grain line where I had perhaps rounded the edge too much and the rawhide backing sanded back too much. Also maybe didn't exercise it enough after sanding. Anyway, it shot 400-500 arrows before breaking and was fun to shoot. There must be an old bowyers saying about not polishing your bison horn tips before ensuring the wood doesn't break.
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That crack follows a grain line. Maybe a smoother transition all around the fades would help. It also looked like the bow was bending a bit too much right out of the fades. Other than that I think it looked good.
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Pat's right, and I would add that your thickness taper in the fade looks to be the culprit to me. Smoother transition for sure but, you have to make the thickness adequate in the fade, especially if the handle is so narrow. It was bending there or at least it was trying to. It found a good place to focus all that stress right on that grain where it broke. Thicker fades.
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Oh no! It did crack along a grain line. On a board you need to have straight grained lines tip to tip or nearly so.You cannot have grain lines that go back to belly.
You did not to do anything wrong except for selecting the wrong board.
See my site for more.
http://traditionalarchery101.com
Jawge
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A few things, I’m too lazy atm to read the replies but here’s my quick take.
•remember there is a difference between grain and the growth rings
•upside down rawhide isn’t recommended but either way it’s glued down it’ll hold all the same.
•your string grooves are just a tad steep is all. To start with just grab a framing square and 45 will get yah in the ballpark. That, or just eyeball it.
•every bow has grain runoff in the fades, just can’t let it work more than necessary in that short section.
•for white oak, or at least the Oregon white oak that I LOVE to work I leave 2 1/4”fades for a bow around 60”ntn and 1 3/4 wide and 4” for fades for a full length ELB or ALB.
•all species of white will make a serviceable bow and in my area (PNW) they where used as war bows.
The downside is it’s fairley compression...... not weak but smooshy. So 2” of set is normal. If you can heat in 5” of reflex it’ll sit flat for years with the proper tiller shape/profile. That being said it’ll make tillering a b*%#€
•with any bow start with a good floor tiller and from there, skip the long string and brace it around 4” ALL flaws will be apparent and just leave it braces and remove slight amounts of wood and excessively short draw/exercise the bow.
Once it looks good. Full brace and continue. Aim for about 5lbs above desired weight so you have some wiggle room. And don’t pull past that weight and it’s as simple as that.
Keep it up man,
Bryce
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Thats a shame,you did a fine job on the tip overlays.your finish work is nice ,with good wood you are going to build some good bows.dont let it get to you and keep at it.
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Are you 100% sure that was white oak and not red oak? I ask because on white oaks, the pores are usually clogged up except in the sapwood (there probably isn't a good way to tell if that is heartwood or sapwood if it was from a board). Your closeup pics seem to indicate that the pores are pretty big and quite open. I had some 'oak' that I thought for sure was white oak, but I discovered it was not after doing some research on it. Unfortunately that research came after I had cut said oak into backing strips for use on some Ipe and said Ipe ripped the stuff apart, explosively, during tillering. Luckily I had fixed my tillering setup to work with a pully so I could stand back and watch the bend. :o
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Thanks for the suggestions and encouragement, guys. I've traced this bow's outline onto a purchased hickory stave (visible under the oak bow in a pic above) and will give it another go, hopefully no backing on the hickory stave and slightly narrower at fades.
To @Sidmand's question, I'm not 100% sure its white oak because I'm relying on what the local non-chain lumberyard told my friend who bought 6, 12 foot 2x10's from them (not for bowyering). He's had a commercial relationship with them for 30 years. To my eye, it does look more pale in color than the red oak at home depot.
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Look at this board. Just about ideal. Your board may have survived a 20# pull. With a board bow the no. 1 consideration is the grain.
Jawge
http://traditionalarchery101.com/boards.html
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Not a whole lot to add as I'm quite new to bow making, but here's a thought for the future... Who says rawhide needs to be smooth? I think the fuzzy side out adds an interesting texture and adds to the "primitive" look. Given the clean lines and smooth finish of the bow perhaps it would be better suited to an "uglier" bow, but worth some thought. Either way I think it was the wood that failed you and not the reverse, you clearly have some talent going for ya.
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Sorry about your bow! It takes a certain kind of mad persistence to keep making bows after one fails on you, and you've got the right attitude. :)
I'm kind of late offering advice, but I'd like to share one thing that I do that has helped greatly in the past. You take the picture of the bow on the tree and open your favorite photo editor. Then overlay an ellipse onto the bow. You should make sure that the ellipse touches four points - the two spots where the arc of the bow starts, and the string nock points. Now, this is for a non-recurve bow, so you'd need two more smaller ellipses for a recurve, and the outer "touch points" will be different.
I find it works best for me when I line up the outside edge of the ellipse with the back of the bow. By lining it up just right, the spots where it isn't bending properly will jump out at you. It's hard to judge by eye sometimes (I didn't see the hinge at first), but this has never failed me.
For example:
(https://i.imgur.com/iVbQj1P.jpg)
EDIT: I was just looking at your image of the break, is that close to where the hinge was in the image I uploaded?
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Should also be noted that each bow design has a designated tiller shape and a single circle or even a couple of them are only useful with absolutely straight staves and boards.
Useful trick when done properly with the right concepts of tiller.
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Keep in mind how much you've learned from this bow. Congrats! On to the next!!
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Are you 100% sure that was white oak and not red oak? I ask because on white oaks, the pores are usually clogged up except in the sapwood (there probably isn't a good way to tell if that is heartwood or sapwood if it was from a board). Your closeup pics seem to indicate that the pores are pretty big and quite open. I had some 'oak' that I thought for sure was white oak, but I discovered it was not after doing some research on it. Unfortunately that research came after I had cut said oak into backing strips for use on some Ipe and said Ipe ripped the stuff apart, explosively, during tillering. Luckily I had fixed my tillering setup to work with a pully so I could stand back and watch the bend. :o
I have worked WO quite a bit and his photos are clear enough that show the wood is whitish, there is definitely not a tinge of red in thar.