Primitive Archer
Main Discussion Area => Bows => Topic started by: Kegan on September 19, 2008, 03:31:22 pm
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If you glued on say, four or five laminations of wood, each one being about an inch or more shorter than the last, until you reached full depth for a deep handled board bow, would this have silghtly more "give" than a full block of wood- provided everything else was equal?
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Shouldn't have any more give than the Wood....seeing as how the Glue Joints are supposed to be stronger than the Wood itself....
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Yes, I think so, theoretically. This is always a problem, when I make a board bow, and want to add a riser. Where ever the riser ends though, there is a concentration of bending. This must be a gradual change or the bow will break right at that line. At least it has happened to me a few times. I end up having to taper the limbs alot from this point.
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Kegan, the key to glued on handles is a long gradual taper to a thick enough handle not to bend. How you get there really doesnt matter, whether it be multiple laminations the way you describe or by just tapering one solid peice of wood the same amount.
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I believe multiple lams are stronger than one riser block, but like Ryan said... a built up riser really shouldn't bend, or it will pop off.
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Kegan
I just finished a r/d hick/red elm ,that I didn't glue the rizer on at limb glue up, so I added several
peaces as you discribed so that it would bend into the deflex and it works pretty good(it was my first try to see if it would work) David
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Thanks guys :). Before, I've tried to leave the originally 3/4" thick board 5/8" thick outside the fades, ut didn't give it a long enough transition. I had though that the multiple laminations, each one being shorter, before gluing, than the one below, in conjuncture with the 1/8" difference, would be more helpful.
For my next one I'll just give more care to the fades. Seems like a little exrta patience and care would be better than any extra steps to help hide flaws, correct?
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Kegan- I think I know what you are driving at. You want to be able to use the full 3/4" board (for example), rather than having to waste 1/8" just to make a safe and proper fade out area from the handle. So you start laminating the riser with an 1/8" thick piece that has a 4" handle and 6" on each side of that, for a total of 16" for the first layer. Then the second 1/8" layer is 1" less in length on each end, for a total of 14", and so on, maybe 5 layers, total making the handle a total of 1 3/8" deep? I think this would be a very good approach. Like was said in a previous post, the key is to make a long, and gradual taper. I have run into this problem, and I will try this step lamination approach next time I get a nice board stave.
But what would be the difference between this "step lamination" approach and just gluing on a 16" (for example) riser made of one solid piece that was 5/8" thick all the way through? Cutting the taper into this one-piece riser can be challenging esp. if you want to avoid cutting into the stave itself. It is also difficult to pre-cut the fades into the riser and then glue on, but this could also be done.
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orcbow- I'm not trying to leave the limbs a full 3/4" thick, but 5/8" thick right outside the fades. The toruble being, this is only an 1/8" drop, and still focuses alot of the ned on improperly done fades. I did a couple bows that were left 3/4" thick, but were stiff in the middle 12". Now that I'm going for a more circular tiller, an 1/8" drop and the same, so-so fade design just won't cut it :P.