Perry reflex & limb twist ... ???

[Knoll]

Something new for me ... & not a good thing.  Doing perry reflex using maple on maple.
Didn't notice until went to short string, but one limb has big time twist.  Other limb is fine.
Is this likely result of how glue-up was done?  I used bicycle tubes and wrapped them from both ends, in opposite directions.  First time had this happen.

[PatM]

 What was your grain configuration and glue?

[Knoll]

What was your grain configuration and glue?

Glue ... tb2.

Not sure about the grain orientation question.  Backing was edge grain from pc of 8/4.   So was the core pc.  Edge grain of the 8/4 board is very straight.  Tried a pic of bow's back.  But, being maple, grain lines are so narrow & light colored as to be (w/ my camera skills) almost invisible.

Took another look at the limbs.  BOTH are twisted ... in opposite directions.  That a clue? 

[Buckeye Guy]

Just guessing here but yes I would say it is the result of your glue up
I dont use the innertube wrap method but I can see how it colud cause twist in a glue up
I build forms for all my glue ups
 Just how I do it

[Pat B]

Since you used TBII you can separate the back and belly with heat, clean up the surfaces and do another glue up.   Be sure the components are flat and once you glue it up be sure it isn't twisted then. Use a clamp at the handle and tips to help keep the twist out.

[Springbuck]

I'm with Pat.

The only time this happened to me, I was using rift sawn jatoba on the belly and both tips wanted to roll toward this   side:   -->  \\\\\\\ .  I was crazy back then, and thaiught I was discovering revolutionary stuff, and poor so I removed the backing with heat, ripped the belly blank down the middle, flipped half and re glued the bow. Like this
////\\\\.    I then destroyed that bow some other way....

[PatM]

The reason I asked about grain and glue is because wood often has some tendency to move  according to grain configuration and adding moisture via glue can exacerbate that.

[Springbuck]

  That's a good thought, Pat.  I could be reaction wood responding to moisture.  I have never had twist, but lots of cupping or curling.  Goncalo alves tries to cup into a raingutter when you touch it with TB III.  I started wetting the whole belly blank before glue up.

[Knoll]

Finished the tiller and ended up with 30# @ 25".  Decided to shoot it 'til breaking.  Got about 50 arrows through it.  So had opportunity to see the lam-to-core glue line. 

Did terrible/terrible job ... prepping lam/core, or doing the glue up, or both.  Lotsa surface area with poor glue adhesion.  Have plenty to work on!   

[paco664]

Finished the tiller and ended up with 30# @ 25".  Decided to shoot it 'til breaking.  Got about 50 arrows through it.  So had opportunity to see the lam-to-core glue line. 

Did terrible/terrible job ... prepping lam/core, or doing the glue up, or both.  Lotsa surface area with poor glue adhesion.  Have plenty to work on!   

at least it died an informative death *(moment of silence)

[Dances with squirrels]

Just for future reference, when you see a bow with one limb twisting to the left and the other twisting to the right, check the limbs for thickness continuity across their widths.

Folks tend to lean tools like rasps, scrapers, spokeshaves and such to one side as they work... which thins and weakens that side causing limb twist. Then they spin the bow end for end and do the same thing to the other side.... and since they spun it around, the twists will oppose each other.

It's not the only cause. As was noted, inner vagaries of the wood can cause it, but if it IS due to how the tools were used, it can be fixed, so it's certainly worth checking on.