Prepping back for sinew

[Blaflair2]

What's everyone's method? I have an osage bow I'm gonna ainew. Usually I use alcohol and rub the heck out of it till the oil doesn't come out

[Pat B]

Bruce, I used a hacksaw blade like a toothing iron to score the back. While the sinew is soaking and the hide glue is being heated I wash the back of the bow well with Dawn dish soap and warm water and rinse it with boiling water. Wipe the excess water off and size the back well with hide glue while it is still wet. I believe this will allow the hide glue to sink into the wood better. When you are ready size the back again and start laying the sinew down.

[Comancheria]

Been doing a lot of reading on this, and can't help but wonder whether scoring the back ACROSS the bow as opposed to lengthwise, might give the glue greater purchase once the sinew starts pulling lengthwise against the wood? (Sort of like steps carved into a cliff)  And if so, would that potentially aid in achieving greater reflex and increase in weight?

[PatM]

Severing fibers even in a surface protected by sinew is  not a good idea, particularly if your sinew layer is not going to be a thick one.
 Your "steps" are likely to be sheared right off.

[Eric Garza]

Fibers are violated on a bow's back anytime the limb changes width. Why would violating fibers by scoring hurt anything?

That said, I've never scored a bow's back in preparation for sinew backing. I just wash the wood several times with dish washing detergent, then lay on the backing. I've never had a backing lift on me, so it seems as though I'm doing something right.

As someone who processes a lot of sinew, I think having clean, degreased backing material that can readily accept glue is given less importance than it should be, and scoring the back is given more importance than it should be.

[bradsmith2010]

osage requires more consideration because of the natural oils,, boiling water is the key when rinsing,, I have lightly scored all my sinew bows as suggested and think it is a good idea,, it is  time tested and proven to work,, I am sure you can do it without,,  I think on osage it is a good idea,,

[PatM]

Fibers are violated on a bow's back anytime the limb changes width. Why would violating fibers by scoring hurt anything?

You really correlate limb width taper with smooth rounded edges with cutting through every single fiber on the back?

[bradsmith2010]

Pat,, do you think it is a bad idea to score the back,, if so,, I will try my next no scoring,, or do you think scoring with the grain is ok,,

[steve b.]

By no stretch-of-the-imagination am I an expert on anything when it comes to bows but, based on my few years of constant research and experience on the subject,  tells me it is counter intuitive to cut the very fibers that you are trying to reinforce.  To me that is like cutting notches in your home's floor joices in order to install reinforcements designed to make them stronger.  But not everything is so obvious, I understand that.
Still, I would rough it up a little with at least some 150 grit and use a light solvent.