Primitive Archer

Main Discussion Area => Bows => Topic started by: DC on June 10, 2015, 06:50:31 pm

Title: Slightly twisted yew stave
Post by: DC on June 10, 2015, 06:50:31 pm

I have a piece of yew heartwood that I'm planning to back with bamboo. It's 65" long and has about 20 degrees of twist. Since I'm backing it can I just ignore that much twist and plane it flat for the boo back or should I rough it out, steam it straight and then plane the back for the boo?

Title: Re: Slightly twisted yew stave
Post by: bowmo on June 10, 2015, 07:48:38 pm

If you think you can swing it, I would straighten it out first.

Title: Re: Slightly twisted yew stave
Post by: wizardgoat on June 10, 2015, 07:55:21 pm

Bowmo is probably right, but if it were me I'd just plane it flat and ignore the twist.  I've never had great luck convincing yew to hold heat bends in working areas

Title: Re: Slightly twisted yew stave
Post by: crooketarrow on June 10, 2015, 10:10:14 pm

 Some stwisted limbs can be hard to keep a hard backing on. So you might want to try to remove  the swtist first.

Title: Re: Slightly twisted yew stave
Post by: Hamish on June 10, 2015, 11:36:32 pm

If the stave is straight and even except for the propeller twist I would just plane it flat and back it.

Title: Re: Slightly twisted yew stave
Post by: Del the cat on June 11, 2015, 02:51:40 am

I'd let the wood do what it want... e.g twist.
Put a flat face on it and glue to that... BUT
Leave extra width in case the limb moves after gluing.
Come to think of it, the same logic applies if you steam it straight....
Mind if you do straighten it, you may as well go the whole way and heat treat it :)
Boo backed heat-treated Yew... that's a fine combo ;D
I've just seen a Hick' backed Osage with about 1/4" sideways bend in the lower limb... you could see the grain in the Osage running diagonally across the limb
Del

Title: Re: Slightly twisted yew stave
Post by: bowmo on June 11, 2015, 11:52:56 am

I guess the real question is does have knots. I was picturing knots. And taking out the twist would keep the knots from running through the limbs at weird angles. And, I've never tried heat correcting yew but once the backing is on the twist couldn't come back.

Title: Re: Slightly twisted yew stave
Post by: Del the cat on June 11, 2015, 12:08:07 pm

Quote from: bowmo on June 11, 2015, 11:52:56 am

.... but once the backing is on the twist couldn't come back.

You believe that?  :o
My experience is that if something stuff will always find a way to wrong... especially if you think it can't >:(
Del

Title: Re: Slightly twisted yew stave
Post by: bowmo on June 11, 2015, 12:16:28 pm

Glue line reflex is a powerful thing my friend...

I have made many bamboo glue ups with wonky boards for cores. Once you force it into a new shape and glue, the whole glue line would have to shift for it to return to its original shape.