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Main Boards => The Bowyer's Bench => Topic started by: razorback on February 10, 2009, 01:17:00 PM
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Well I have an osage stave roughed out and it has 1" of natural reflex and about 1" of warping end to end. I was planning on heating it to straighten it out so the string will run through the handle. I was also considering adding some more reflex to the bow. This is my first osage stave bow and have heard that adding reflex makes tillering complicated and not the best option for a begginer. However since it already has reflex that I will have to deal with would adding some more make it more difficult or just add to the quality of the design. Any and all thoughts, suggestions or comments would be greatly appreciated.
View of warping looking at the back
(http://i648.photobucket.com/albums/uu207/aussiearcher/013.jpg)
Closeup of Handle area
(http://i648.photobucket.com/albums/uu207/aussiearcher/014.jpg)
Reflex of bow.
(http://i648.photobucket.com/albums/uu207/aussiearcher/015.jpg)
closeup of handle area showing reflex.
(http://i648.photobucket.com/albums/uu207/aussiearcher/016.jpg)
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I have a caul or bending form that adds about 2" of reflex. All staves get the same treatment. 2" of reflex won't make tillering too hard.
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I agree with John. You can reflex and remove the sideways bend at the same time with a form and some heat.
Is that crack in the side going to be a problem?
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Thats the crack that we have spoken about in another thread. I am going to glue it with super glue or epoxy, probably super glue. I'm hoping the cracks that are in this one will be fine with the glue treatment and I will still end up with a bow.
When making the caul, what shape of a curve do you suggest for inducing the refex.
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I like a nice even bend through the entire bow. 2" to 3" of added reflex is plenty. Adding more can over stress your bow and cause more set in the long run.
I think super glue is your best bet to get down deep into that crack.
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Thanks for your input Pat.
In trying to straighten and induce some more reflex, hwere would you start. I am having trouble tying to determine where to start clamping and heating to get it all in place without putting too much stress on the bow.
Tony
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I usually start by clamping the handle to the form and work out each limb to the tips. I work both limbs together, a little at a time instead of out one limb then out the other.
Heat a little out one limb and clamp it(I use wedges sometimes at problem spots)them go to the other limb, then back to the first and back to the other until I get to the end of each limb.
When you remove the cooled bow from the form you may still have to make some adjustments. Sometimes heat is required but often this is where leaving the tips and handle area wide and thick come into play. Slight adjustments can be made by removing wood from one place or another to get everything to line up.
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Do you go down with the reflex and across with the straightening at the same time?
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First thing to do is, if I'm looking at the back in the second pic, is to take it down to one growth ring. You can hop a ring in the handle if it is rigid enough, but it's ill advised unless there is compelling reason, some other flaw in the stave typically. ]
Then, again not obvious in the pics, get it reduced down to at least near floor tiller stage. It will make your heat straightening go much easier.
Finally, the caul can be as simple as a 2x4 and some chocks or little blocks of wood of various thickess to "pad up" certain areas to bend around with your clamps along the lenght of the bow. This makes the floor tiller more important, as the it's easier to predict a fairly even right and regular bend of the limbs. This will help one "see" and control the final shape during the heat straightening process.
You can correct both profile (from the side where the arrow pass is) and plan view (from the back or belly view) in one pass, or take your time and use lots of little sessions. It's personal preference. It tend to steer less experienced folks towards the former.
Only other advice for heat straighening is take your time. Let your heat soak, using either enough distance or constant motion to avoid any discoloration, at least at first until you get a sense of what you can get away with. I will typically heat an area of say 5" to 7" for at least 5 minutes before I try to move it, and then test with clamp pressure to see if it's softened enought. It's a thing one must develop a "feeling" for by trial and error. If you get in a rush, you might blacken the back ring worst case scenario. I'm speaking from experience here LOL. Don't mean to mislead here, always apply heat from the belly side but with a caul the heat will concentrate between the stave and caul sometimes.
From an experienced pov, you got a very game a viable project on the bench from what I can see.
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thanks DCM. yeah this is a project. The crack in the handle is one ring below the ring I want as my back. i had another issue with a crack that determined the start point of the belly. If I go down one more ring I don't think I will have enough wood in the limb for the 50# I am shooting at. There is also extra wood on the back of the handle that is over a knot. Will probably reduce that area but as it is in the handle and I intend to keep the handle stiff I don't think this is an issue at the moment. Thanks for the advice. I think I will bring it somewhat into line before going for the reflex. This is my first heating efforts so I will take it real slow.
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I like to use oil on wood that I am trying to straighten or add reflex with heat. I believe the oil helps the heat to soak into the wood more evenly and it helps to retain the heat longer as I am working on straightening the stave. And like David said be careful not to scorch the back.
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Sence this is first bow to me heat bening is not even in the picture.This only as far as i'm concerned.Which dose'nt matter a whole lot.Here's what I would do.First if it were a green stave i'd ruff it into bow form clamp it slow'ly onto a form and let it season.Or mark your bow out the best you can to where the tips line up with your handle the best you can.And try to take out the rest through tillering.If that can't be done get another stave save this one for when you get a couple bows under your belt.You may find out that the stave is'nt as bad as you thought.