my hemp backed Hazel bow has lost weight and gained set!?!

[JoJoDapyro]

I'm not understanding... Either the scale was wrong, or you were shooting the bow while the backing was still wet?

[sieddy]

Hi Jojo that's what I didn't get I left the bow while the backing was drying and the scales are fine (they are not the best but are consistent)

[PatM]

Was the bow shooting at full draw and then you decided to back it?

[sieddy]

Hi Pat. Yeah I was a little concerned about the back after scraping off the cambium. I thought the backing couldn't hurt! 

[bradsmith2010]

if the backing put moisture in the bow, it would need to dry a week or two before shooting again,if it is humid where you are,, maybe even needed a heat box,,, sounds like a moisture content issue,, maybe hemp attracts moisture more than other backings,, I have not tried it,,  try putting the bow somewhere very dry, and see if the weight goes up,, I am not sure if the set can be fixed,,

[sieddy]

Hi Brad thanks for chipping in - i definitely think it was the moisture. I'll have to live with the set but will get the backing off and see what I can do to save it.

[GB]

Whenever I use Titebond to glue on cherry bark backing, it raises the bow's moisture content quite a bit.  Like Brad said, either let it dry for a week or so if the RH is low enough or put it in a hot box before shooting it.  I haven't had any set issues after getting the MC back down before shooting it in.

[WillS]

It might not be anything to do with the backing at all.

A white wood bow needs to be tillered perfectly, kept incredibly dry while being worked and then lightly toasted and sealed with a good modern sealant.  If not, it  will take set regardless.  Taking set will reduce draw weight.

It's not unusual to finish tillering a bow that has zero set, and after a few weeks of shooting end up with a banana.  Tillering only goes a very small way to work the bow, whereas shooting is much tougher on it.  You can get close to emulating the stress when tillering by exercising the limbs a LOT as you increase the draw length - say 40 times every inch - but it will still take some set as its shot in.

Any white wood bow needs to be tillered delicately as well - some woods let you pull the bow until you see an obvious hinge and then resolve the issue, but most white woods (ash and hazel in particular) don't.  You need to be spotting hinges before you even see them, predicting where its moving too much, and visualising where it's going to hinge as the draw length increases. 

They're great woods for bows, but fickle and fussy!

[DarkSoul]

I wouldn't remove the backing at this point. First try to post some pictured of the bow, also at partial draw. We might find another culprit for the set.

[sieddy]

Thanks for the input fellas I will post some pics tomorrow for the postmortem but sadly I have already taken the backing off.

[crooketarrow]

  I'm the type person that constantly moves forward. On my own turms.
 
  MOVE ON LEARN FROM THE EXSPERANCE.

 BUILD ANOTHER BOW.

 If you stave was seasoned enough. That was'nt your problem.

 It's low weight so that did cause your problems.

  So I hate to say it but likely was your tillering.

  I never fix a bow if it was my faught. And even then very liky it's worth fixing anyway. Your just trying to save a little face. You never want to make that misstake again. So don't try to fix it. MOVE ON build another bow, not makeing that misstake again.

  Each time you make a bow the more insight you have into building another.
 

[sieddy]

Hey Crooketarrow I hear you man and I myself am quick to move on from my mistakes -I have a few works in progress to get on with! 
But I will have a play around with this bow to see what results prior to putting it in the fire. I ain't got nothing to loose now have I. 

[PEARL DRUMS]

I find it hard to believe dryness was an issue. Reason being, it would have never registered numbers that high to begin with. Wet backing give up the ghost right away. Been there.

[PatM]

I think it registered high unbacked and then he added the backing and started using it while the bow was still damp.

[PEARL DRUMS]

Ahhhhh. That makes sense.