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Main Boards => The Bowyer's Bench => Topic started by: bowhntineverythingnh03743 on March 23, 2014, 04:46:00 PM

Title: Slight limb twist.... Fix??
Post by: bowhntineverythingnh03743 on March 23, 2014, 04:46:00 PM
Ok guys after putting on the tip overlays and leaving the bow in the oven for 4 hours I developed a slight twist in one bow limb from the bow falling off of the supports and putting pressure on the limb. How do I go about fixing it? Do you do the sand on the stiffer side and deepen the weak side knock or is there a different way to fix this. I know it can be fixed because it is only slightly off but I am not sure how about doing it

Here is the best picture I could get of the limb so I hope it gives you an idea of what I'm talking about...

 (http://i1177.photobucket.com/albums/x344/bowhntineverythingnh03743/IMG_0518.jpg) (http://s1177.photobucket.com/user/bowhntineverythingnh03743/media/IMG_0518.jpg.html)
Title: Re: Slight limb twist.... Fix??
Post by: 4est trekker on March 23, 2014, 07:11:00 PM
I'm not sure that your proposed fix will actually solve the problem.  That is, a tiller-induced twist is caused by once side or the other being stronger.  In your situation, the twist is caused by a pear-shaped glue-up, not improper tiller/uneven thickness.

That said, I'm not a glass bow builder, so I don't know if/how to fix it.
Title: Re: Slight limb twist.... Fix??
Post by: bowhntineverythingnh03743 on March 23, 2014, 07:15:00 PM
Well after a search I am attempting to soldtly heat the twist out over a couple of attempts. Got clams on the limb to even it out and now letting it cool. I went slow as to not overheat and delam the limb... So far everything is holding well and cooling so I will see if that helped at all. Fingers crossed!!
Title: Re: Slight limb twist.... Fix??
Post by: kennym on March 23, 2014, 08:32:00 PM
That's a tough one Justin. Not sure how to correct it except what you are doin!

Let us know how it works out!
Title: Re: Slight limb twist.... Fix??
Post by: chackworth3 on March 23, 2014, 08:51:00 PM
That is a tough one. I had one do the same thing once when the top half of my form bowed slightly in the oven. Tried all the same things you tried but it was too far gone...very disappointing. Hopefully you will have some better luck   :thumbsup:  let us know how it turns out
Title: Re: Slight limb twist.... Fix??
Post by: wood carver 2 on March 23, 2014, 10:12:00 PM
MMM! Steamed clams.    :)    :rolleyes:    
Dave.
Title: Re: Slight limb twist.... Fix??
Post by: bowhntineverythingnh03743 on March 23, 2014, 10:23:00 PM
Lol sorry was texting just after taking a nap... It's dangerous to do that!!!! So the limb  seems to be coming back around. Little more tweaking and I think I will be there. Started to shape the riser tonight.
Title: Re: Slight limb twist.... Fix??
Post by: heartlandbowyer on March 23, 2014, 10:52:00 PM
I use CA thick on all of my tips and overlays now so I only end up cooking the bow once. When I first started I cooked a bow twice and almost lost the bow because the 2 woods  in the riser were of different moisture and density and started to move as they heated up causing a crack on the seam.

Keep at it, sounds like your getting close on saving it.

Cory
Title: Re: Slight limb twist.... Fix??
Post by: Robertfishes on March 24, 2014, 11:03:00 AM
I mostly use CA for tips too. When using smooth on for tips I put a lamp with a 75 watt bulb about 1 ft from bow tip, i put a thermometer next to tip .temp only gets about 90- 95 degrees and the smooth on sets in 2 hours but fully cures in 24 hours. When you put clamps on the tips and add too much heat you can soften the smooth on and the weight of the clamps can twist the limb . A post was made on this subject about 5 years ago, I saw it and decided to not cook my limb tips over 100 degrees after the bow comes out of the form..my oven runs 165-180 degrees for the glue up
Title: Re: Slight limb twist.... Fix??
Post by: bowhntineverythingnh03743 on March 24, 2014, 12:57:00 PM
Yes I have learned from my mistake and will NEVER cook the bow again once the initial glue up is done. I have fixed the problem and it seems to be holding. Got the riser and tips all roughed shaped and I have been shooting it. I have seemed to have gotten lucky on this one and saved it!

Here is the limb now

 (http://i1177.photobucket.com/albums/x344/bowhntineverythingnh03743/64166815-6cff-4cdb-9b73-0fbce17278a4.jpg) (http://s1177.photobucket.com/user/bowhntineverythingnh03743/media/64166815-6cff-4cdb-9b73-0fbce17278a4.jpg.html)

I was very lucky with this one and again I will never cook a bow for a second time!!! Thanks for all the input guys.... Justin