Tiller Suggestions - things didn't work out.

[mwosborn]

Just wondering if anyone would give suggestions on tillering out this osage mostly sapwood bow.  It was cut last April - about a 3" diameter sapling.  Split and clamped to a caul for a couple of months to keep from warping badly.  Then has been drying in the shop since then.  63" tip to tip.  1-1/4" wide to midlimb then tapers to 1/2".  Back of the bow is just under the bark.  Most of the heartwood has been removed to this point although some does remain.  The larvae had eaten some holes/trails in the sapwood - these were filled with titebond 3 and sawdust.  Bow was then backed with rawhide.

Currently I am out to 23" and it is pulling just over 50#.  I am wanting to get to 27" or 28" and 48-50#.  The upper limb is on the right.  The arrow pass is centered on the tree.  The original unbraced profile showed just a bit of relfex.  Starting to show a bit of set - more on the upper limb.

At 63" do you think I need to get the fades and handle bending some to get to 28"?

Thanks for the help!

Mitch

   IMG_0396  by  mwosborn1 , on Flickr

   IMG_0393  by  mwosborn1 , on Flickr

   IMG_0395  by  mwosborn1 , on Flickr

[mikkekeswick]

I'd say make the tiller of the right limb the same as the left. As it is it's bending too much in that inner third. Your left limb is showing an elliptical tiller how it should be.
Once you get both the same then start to work on and through the handle area to further your draw.

[John Scifres]

You can afford to have a more elliptical tiller since it is 63".  That means you can probably get the last few inches of bend by correcting as Mike says and then removing weight equally from both limbs.  I don't know that I would get it bending a whole lot more in the handle/fade area.

It's looking really good though.  At 1-1/4" wide, you can probably expect more set in an all sapwood osage than a heartwood bow.

[mwosborn]

Thanks for the help John and Mike!  I will work on it some more and see how it goes.

[mwosborn]

Worked on it a bit.  The first pic here is the same one in the original post except with an oval added.  The second pic is after a little bit of scraping.  I pulled to 24" now and it is currently at 50#.  I think I will slowly reduce some weight and see if I can get it out to 27" without going BANG!  

Maybe a few more scrapes on the outer third of the right limb?


 IMG_0395  by  mwosborn1 , on Flickr

 IMG_0407  by  mwosborn1 , on Flickr

[Roy from Pa]

Looking nice, Mitch..

[mwosborn]

Thanks Roy.

We will see how it turns out!  

[mwosborn]

To make a long story short...

I wasn't happy with the set this bow took so I worked on it for awhile and eventually broke it. Here are some interesting pics of the dissected bow.  First pic is where it cracked about 8" from the tip and I scraped down a bit to see the damage.  Second pic is where I cut the limb in half at midlimb to see what it looked liked inside.

Lessons learned...

Osage (even "wormy") is some tough wood.
If there is insect damage on the surface, it is probably worse inside.
Select quality wood with no insect damage.
Heating osage sapwood will increase weight.
You can heat treat the belly without damaging the rawhide on the back.

 IMG_0444  by  mwosborn1 , on Flickr

 IMG_0447  by  mwosborn1 , on Flickr

[John Scifres]

Yikes.  Where was this piece stored?  That is a heck of a lot of bug damage for less than one year.  

I will add to your list:

- Store your wood inside.  

- Get the bark and sapwood off as soon as possible.

[Roy from Pa]

Also spray bug killer on your staves.

[mwosborn]

That is the thing John - it was stored inside my heated/air conditioned shop.  Bark was removed right after it was cut and the sapwood sealed.  It was a sapling so the sapwood was not removed.  Very little damage on the surface of the wood (a couple of tiny holes where the larvae must have gone in) - the damage was taking place inside.  Check out the second picture and see how deep them little buggers were from the surface.  Had nothing to do with where or how it was stored - it was doomed from the moment I cut it.

Roy - I spray them with "sevin".

[Roy from Pa]

Well ya should have used eightvin..    

[John Scifres]

Was the tree alive when you cut it?

[mwosborn]

LOL - yep John it was alive.

[ColonelSandersLite]

Truth is, you can never know for sure what's inside a piece of wood.  All you can do is try and stack the odds in your favor, or stop using organics all together.  I've seen some pretty messed up stuff doing carpentry stuff over the years.