Primitive Archer
Main Discussion Area => Bows => Topic started by: Wooden Spring on December 10, 2013, 04:39:59 pm
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OK, so I'm getting ready to laminate up some hickory and red oak for a pyramid bow, and I wanted to try something new this time... I want to add some static recurved tips. Are there any rules governing how to make them? As in, height above the back plane line of the bow? Length that the recurve extends down the bow towards the handle? Etc...
In case the bow specifics matter, this one is:
1/8" hickory over red oak - flat with no glued in reflex
66" NTN
2" wide fades
1/2" wide tips
8" long handle/fade area
Weight... Whatever it winds up being...
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You have to glue it in you can't bend it after it is glued. If it hadn't been glued, there is no real rules on recurves, just glue it up!
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I think you'll want to put the curves in your wood before glue up. Most glues don't tolerate the moisture or heat typically used to achieve recurves very well. So, if your using Oak belly wood, i'd assume it's a bit thicker. I'd get the hooks made on the Oak, and then heat the hickory lams up before gluing them on to the Oak cores.
OneBow
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If adding true statics(string contacting at brace) you will then need to bend your curves into the belly lam first before glue up....and then the backing strip will be so thin it'll conform to the static recurve shape during glue up and doesn't need to be heat bent like the belly lam does before gluing
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If you leave the tips thick, bend them into shape (and let dry), then reheat them to scorching (or toasty) and add oil, they should stay that way without laminating - and you get a cool primitive toasted look on the recurves. Works for me anyway.
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You can also splice in static tips. No heat or bending required.
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I always like to use a wood that is virtually 100% guaranteed to bend easily without cracking and then splice that into the tips of a shorter stave from a wood that may not bend as reliably.
Here is a bulletwood belly, backed with Ash and with spliced in Elm tips. The backing is added after the tips are spliced in and an underlay is added to the splice on the belly side.
Ignore the crude tillering string.
(http://i399.photobucket.com/albums/pp78/pat_05/002.jpg)
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That's pretty Pat
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Wow. Nice job
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You should definitely bend your wood first before glue up. Bending the backing may not be entirely necessary but I prefer to bend the backing and board as one. I typically boil or steam to achieve the bend, especially on white woods. Bending the backing may not do much but it let's me sleep better. In my mind there is some, albeit small, amount of force the backing is pushing against your core wood. Does that hurt? I'm not sure, and if it does it's probably a small amount but bending the backing makes sense to me and is not difficult or time consuming. Just one less thing for me personally to worry about. Matt
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If you're doing static recurves is there any reason for the backing to extend into the recurves?
Don
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Continuity of your backing strip is always best. Otherwise the edge where the backing presumably would feather out might lift.
Certainly if you're going to splice a tip in it holds the splice together better although you can just wrap it also.
I bend the static main part first and then use it as the form to bend the steamed backing strip. The thin backing strip needs minimal steaming and you only have to get it close to the curve. Let it dry and then you can muscle it a bit with your clamps to get it perfect if you're gluing surfaces are good.
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Continuity of your backing strip is always best. Otherwise the edge where the backing presumably would feather out might lift.
Certainly if you're going to splice a tip in it holds the splice together better although you can just wrap it also.
I bend the static main part first and then use it as the form to bend the steamed backing strip. The thin backing strip needs minimal steaming and you only have to get it close to the curve. Let it dry and then you can muscle it a bit with your clamps to get it perfect if you're gluing surfaces are good.
That's how I do it too. works great.
I've had a backing lift that did not go all the way to the end. The backing I used was just long enough to cover the working limbs. I didn't have one longer so I used it. forgot to wrap it. I'm confident it would have held if I did though.
So if you don't have your backing go all the way do yourself a favor and wrap it as Pat suggests. I would much prefer to have backings go all the way to the tips though.
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Maybe Pat or someone else with more experience on hickory backing can jump on here. I mainly use bamboo when I back a bow and I taper the thickness to near nothing at the tips. I'm not sure if that's applicable to hickory backings. That keeps tip mass down but still gives me piece of mind. If your doing a true static, running the backing past the last moving point should be good but I'd still Wrap it with sinew there just to be sure.
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A kerf cut is another easy way to bend the tips without heat.