Primitive Archer
Main Discussion Area => Bows => Topic started by: jojo on February 05, 2014, 07:41:56 pm
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Hey all,
This is my first real attempt at making a bow. It's a hickory board bow, 66" pyramid bow 1 3/4" at fades. Going for 50-55# @ 26".
Here's the problem. I was roughing out the shape with a rasp and a deep splinter lifted cutting its way into the back of the bow at mid limb. Is there an easy fix for this or do I need to start over? I'm afraid the limb will break at that point if its not properly addressed. What are my options?
-jojo-
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Looks like you probably have enough meat left on the other side to just remove the damaged area. You might need to narrow the whole thing though, and you should adjust your expectations for draw weight accordingly. Judging from what I can see, I think I would narrow the limbs until that splinter is gone and continue on.
Also maybe you should consider backing it with linen or rawhide or silk.
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I don't think I would narrow a hickory, I think if it was mine, looking from here, I would super glue it down, trap the back a little and it will likely disappear . If your not familiar with trapping the back, do a search, if nothing shows up, give a shout and i'll try to explain............ good luck I like hickory.
DBar
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Looks like you have some pretty bad grain run off right where that splinter lifted. In fact it lifted perfectly along where the grain goes funky and swirls about.
That's exactly the kind of thing all the build alongs and books and experts say to look out for and avoid - I don't know enough about board bows to offer any help on where to go now, but common sense would suggest that in that area you might be asking a lot for the bow not to fail without some substantial backing. Somebody who actually knows what they're talking about should be able to help though!
Good luck, either way!
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Round all your edges. I'd put a bit of super glue in the splinter before rounding there.
I try to keep all the edges rounded on any bow while I'm making it. Its easy enough to do with a few swipes of a scraper.
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If you trap the back it will likely dissapear.I like to use 120 grit plumbers sand cloth for rounding off all the sharp edges.
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I still think you can recover this one. But you will have to do like bushbow, PatB, and Danzn Bar are telling you.
1) soak that spot in super glue. And don't use the cheap-o stuff in the tiny tubes. Go tothe hardware store or to a hobby store and buy the larger bottle. You might want to look for the superthin penetrating stuff.
2) Once the glue has set up, "trap" the back. Basically, you are narrowing the back of the bow and leaving the belly at the same width. Not a lot of material needs to be removed, even less than one eight of an inch on each side will really do a lot of good.
3) Round over all the edges of the limb. Rounded edges will help distribute the stresses around the edge, instead of focusing it on a sharp corner.
Glad you caught this now instead of yor first time at full draw!
Now, go lick 'em! Post pics of progress as always.
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Thanks JW...... I couldn't of explained it better, I'm better at hands on showing than a verbal explanation. :)
DBar
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Looks like you got a lot of grain runoff
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Been there done that multiple times, i make allot of hickory board bows..do as patb said and round the edges, its no biggy.
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Thanks JW...... I couldn't of explained it better, I'm better at hands on showing than a verbal explanation. :)
DBar
Just distilled what had already been explained.
Joec123able, I have seen much worse on hickory board bows I have built. I still think this one has a better than even chance of making it to hunting season this coming fall.
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Looks like you have some pretty bad grain run off right where that splinter lifted. In fact it lifted perfectly along where the grain goes funky and swirls about.
That's exactly the kind of thing all the build alongs and books and experts say to look out for and avoid - I don't know enough about board bows to offer any help on where to go now, but common sense would suggest that in that area you might be asking a lot for the bow not to fail without some substantial backing. Somebody who actually knows what they're talking about should be able to help though!
Good luck, either way!
There is a little swirl in that spot. I followed a straight grain line from ntn. In fact the pencil line in the middle runs right over top of that natural grain line, so from what I read it should be laid out right but not entirely sure.
I still think you can recover this one. But you will have to do like bushbow, PatB, and Danzn Bar are telling you.
1) soak that spot in super glue. And don't use the cheap-o stuff in the tiny tubes. Go tothe hardware store or to a hobby store and buy the larger bottle. You might want to look for the superthin penetrating stuff.
2) Once the glue has set up, "trap" the back. Basically, you are narrowing the back of the bow and leaving the belly at the same width. Not a lot of material needs to be removed, even less than one eight of an inch on each side will really do a lot of good.
3) Round over all the edges of the limb. Rounded edges will help distribute the stresses around the edge, instead of focusing it on a sharp corner.
Glad you caught this now instead of yor first time at full draw!
Now, go lick 'em! Post pics of progress as always.
Do you know of a goo brand of superglue for this job?
-jojo-
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There's nothing wrong with the gain, looks great to me.
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The stuff they sell in hobby shops is plenty good. My local hobby shop has some manufacturer throw the shop's label on the bottles, so I have no idea who makes it. But I can get it in the regular, super thin (will penetrate tightly threaded nuts on a bolt and seize them up tight! Don't ask. ), and one so thick you almost have to slice it to get it out of the bottle!
They also sell an accelerator for it, but you cannot use the accelerator on the superthin stuff.
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I would just use Loctite Professional, you can get it at walmart or any lowes, home depot etc...
DBar
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The grain on the back looks fine enough. The problem is the grain on the side. Really bad runoff. IMHO no amount of trapping or backing with anything is going to save that one. You want the grain lines on all 4 sides to run reasonably straight down the board and this one isn't it.
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Good advice above,should work out,one thing to remember that will help you avoid this in the future is always file from back to belly,then if you do get a splinter it is on the belly,not near as much of a problem. Good luck. :)
Pappy
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Is this not exactly what people mean when they talk about selecting a board with straight grain? I've drawn along the grain lines.
(http://i1202.photobucket.com/albums/bb363/Will_Sherman/grain_zps60245dc7.jpg) (http://s1202.photobucket.com/user/Will_Sherman/media/grain_zps60245dc7.jpg.html)
Or does the grain along the back not actually matter? Shows what I know about board bows!
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Flip it and make that the belly side...
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Hickory isn't indestructable. Flatsawn boards are much, much easier to read if you aren't sure you know what you're doing when selecting them.
If you really want to carry on with it i'd trap the back by about 1/4 on both edges and then back with thick rawhide.
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..and this is why I don't make many self board bows. It's very difficult to get good grain on a thick enough single piece of wood. Laminate board bows are the way to go IMHO. Plus, you get to optimise your chances of success by using tension strong backing wood, and compression strong belly wood.
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i think everyone reads too much into grain orientation. with hickory, if the board is quarter sawn and the grain is fairly straight then you got a good board. run offs are inevitable, you cant taper the limbs without causing a hundred different run offs, its impossible. ive never paid attention to the grain on the side of the board. ive yet to find a perfectly straight hickory board.
now with red oak, thats a different story, im way more picky.
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The grain on the back looks fine enough. The problem is the grain on the side. Really bad runoff. IMHO no amount of trapping or backing with anything is going to save that one. You want the grain lines on all 4 sides to run reasonably straight down the board and this one isn't it.
It does runoff there. Didn't see that before. I checked all edges and found that about every 20" one grain line runs off. The area you pointed out is by far the worst example and the rest of the bow runs much straighter. Not sure if that makes a difference or not. I imagine that splinter area may be the weakest point.
-jojo-
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JoJo ... just give it a go and see what happens, doesn't take that long to fail or make a shooter...... ;)
DBar
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Question
Not sure if I laid this out right, sorta made it up this method. I took my board that was about 6" wide and lightly traced a single straight grain line down the board with a pencil. I measured 66" along that traced grain line and drew to tick marks for the length. I then used a long straight edge and connected those to tick marks, drawing the straight center line darker than the lightly traced grain line. That grain line hugs that straight edge center line very close.
My goal was to have a few grain lines run the entire length of the board. Is that how you guys do it too or am I making this too hard?
-jojo-
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JoJo ... just give it a go and see what happens, doesn't take that long to fail or make a shooter...... ;)
DBar
Totally agree. Already have it superglued and still researching trapping. I think an 1/8 inch would cover the splinter but I'm not exactly sure the best way to make it even all the way down to the tip. If anyone has links let me know, I wanna give it a good honest and educated try. I'll keep posting pics of my progress in case anyone is interested.
-jojo-
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Question
Not sure if I laid this out right, sorta made it up this method. I took my board that was about 6" wide and lightly traced a single straight grain line down the board with a pencil. I measured 66" along that traced grain line and drew to tick marks for the length. I then used a long straight edge and connected those to tick marks, drawing the straight center line darker than the lightly traced grain line. That grain line hugs that straight edge center line very close.
My goal was to have a few grain lines run the entire length of the board. Is that how you guys do it too or am I making this too hard?
-jojo-
your making it hard on yourself. draw straight lines. you dont need to follow the grain with boards unless they are really wavy(which you shouldnt buy in the first place). if the rest of the board has straight grain like im seeing in the pictures then theres no need.