So I just got this osage bow here onto a short string and the string sits ~1/2'' outside the handle. As you can see in the pics one of the limbs is mostly strait while the has a noticable sideways bend, its also a bit propellar twisted. I think this is the problem.
Looking down at the crooked limb.
(http://i.imgur.com/SLUzfCN.jpg)
And the crooked limb at eye level.
(http://i.imgur.com/bmEO5w4.jpg)
Incase it helps, top down pic of the offending limb
(http://i.imgur.com/GbU0O8V.jpg)
So what should I do?
My first thought was too steam the limb in question and clamp it laterally. So the clamps will be contacting one side of the bow, not the back or belly. Clamp it a little past strait and leave it for 12 hrs.
But could I just do that with the handle? Correcting the entire limb that way?
Should I use dry heat or steam and why?
How long should I wait with either before finishing tillering? Keeping in mind I live in the desert, so low humidity, high heat which will steadily be getting drier and hotter in the coming weeks.
Whats a good set up for clamping? I've seen setups for getting some backset into/out of a bow with two blocks on either side of the handle, and the clamps between them. Should I adabt that too this?
And any useful tips or mistakes too avoid for this operation will of coarse be greatly appreciated by someone who's never done it before =p
Mark, do you have a good flat bench to work on? If so clamp or screw a 2x4 onto the front edge.
Lay the bow onto the work surface with the curved out area facing away from the 2x4, assuming the osage is dry, heat the curved area with a heat gun, only heat from the belly of your bow. When it is too hot to touch place a clamp strong enough to pull the stave straight or slightly past. Let it cool, I usually let it sit overnight before unclamping.
The stave in the photo doesn't seem to be twisted that bad to me, but if it does need straightened we can help you with that also.
(http://i.imgur.com/YK7Ft8L.jpg)
So the set up will look like this?
Yes the wood is dry, will the heating dry it out eneuogh that I should wait for it to come back to equilibriam?
The twist is slight yes, it's not a problem I just mentioned it for thoroughness.
Here is a crude jig that I use if I need to bend the handle to line up limb tips, works great with my vise. shown bending a bamboo back/belly osage bow. Jig is made out of osage scraps. Bow was glued up with unibond dry heat glue held up fine.I use the same method as Dan for most of my heat bending also. (http://i1271.photobucket.com/albums/jj633/darinputman/20160314_202442.jpg) (http://s1271.photobucket.com/user/darinputman/media/20160314_202442.jpg.html)
Nice setup darin, simple.
Followup question: If I''ve decided to heat bend a spliced handle will that change the equation? What if it has a glued on riser?
I have no experience with heat bending a spliced handle myself, but by the looks of your photos you can get by without bending it in the handle area, which is the direction I would be inclined to go. I had a glued up back so I went to the non working/less stressful area to bend. Plus I was using unibond and also had the advice of my teacher and friend Eric Krewson who thought the unibond would hold up to the heat. Lots of folks here with a lot more experience than me hopefully they will chime in, I made a few messed up a few but learn from them all. Good luck
Ive never tried bending anything that was glued up. Sorry not much help there.
I have heat treated BBO bows glued up with unibond. Concentrate 80% of the heat on the belly side and 20% on the boo side.
Mark, looks like you left the handle and nocks wide. Cut the nocks further on the offending side. You can then even them off.
That will only move the string a little bit.
This is ho I fix twists.
http://traditionalarchery101.com/fixtwist.html
Once you get the string on the handle you can shape the handle accordingly.
String does not have to be catered exactly to be a good shooting bow.
Jawge
Osage has character
This one was snakey on one end so I bent the other end to line the string up.
(http://i1293.photobucket.com/albums/b593/osagemark/osage%20%20snake%202017/100_1000.jpg) (http://s1293.photobucket.com/user/osagemark/media/osage%20%20snake%202017/100_1000.jpg.html)
Get your limbs bending more, like to floor tiller stage. This will reduce the wood to be heated for correction making it correct easier but also you truly won't know how the string tracks until first low brace.
Here is my rig, everything I use for bending.
(http://img.photobucket.com/albums/v181/ekrewson/bow%20making/straighteningtakedown.jpg) (http://smg.photobucket.com/user/ekrewson/media/bow%20making/straighteningtakedown.jpg.html)
I have a vise that swivels and a stout post on the end of my work bench to use for leverage.
I turn the vise sideways so tightening it will press the victim into the post, add my aluminum angle for a reflector and wrap the bending part up with an old tee shirt, hot angle and all to hold the heat while it "soaks" after a bend.
This is a take down that got askew during the sleeve gluing process and needed to be realigned.
On other bows I usually bend the handle if the tips are out of alignment. I have bent dozens of spliced handles that were glued up with urac, no problems.