Primitive Archer
Main Discussion Area => Bows => Topic started by: deermaster on June 26, 2007, 09:08:57 pm
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what is the best way to add reflex to a hickory composite? is there a certain part of the limb that you reflex or is it a gentle "half circle" sort of reflex? pics of forms and finnished bows and bows in progress wouls be great!!! thanks for any info or pics. also is urac a good glue?
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The best way is probably to lightly pretiller the belly slat and glue it up into reflex when you add the backing. You can do this by clamping it to a form (for a deflex/reflex), or by clamping the handle down and raising the ends on blocks (works well for reflexing the whole limb). As for which you do, either works well. Too much reflex can make a bow unstable, though. Urac is probably as good a glue as you can get for glueing up laminated bows.
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It also depends on how many laminations are going into the bow. If you have 4, you can glue the inside 2 into a little more radical reflex. Then when you glue on the belly and back, you pull it back into a sleight reflex. This will make the center under more pressure when braced. The belly and the back will be under less reflex to help prevent failure. Justin
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deermaster,
you can also try the yumi glue up style. You criss-cross rope the whole length of the laminations, after adding glue, and then hammer in bamboo or wooden wedges underneath the crosses. If you put the wedges on the belly side, they'll create an even reflex throughout the whole limb. (http://i2.photobucket.com/albums/y46/Samuraiwarrior2/Retos%20Turkish%20bow%20pics/Slide15.jpg)
Here's one of a Turkish bow with a horn strip being glued on in this fashion.
http://198.170.108.27/phpBB2/viewtopic.php?t=395&highlight=wedge
(http://i43.photobucket.com/albums/e362/bowsforpros/IMG_0532.jpg)
If I were making a backed bow, I would definitely use this method. I would also use hide glue instead of an epoxy. Size the lams a few times, apply one thick coat, bind and wedge. Then, reheat the bow to activate the glue again and ensure a good bond. I can't get Urac at any local store, but I have fallen in love with Knox unflavored gelatin as a glue.
Just make sure if you use this method to put the wedges on the belly side, otherwise you'll create a deflexed bow.
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Well, that is quite clever !!!
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also a good glue up method is using the inner tire of a bicycle. You wrap it TIGHT on the bow and then tie the ends. voila, no clamps or nothing needed.
You might want to put painters tape on the sides of the bow though, for preventing the rubber sticking to the excess glue dripping from the sides.