When should I add rawhide backing?

[Blllkns]

Hi everyone this is my first time posting. I just broke my second try at a bow, I had it roughed out and had just finished steam bending the handle section to get every thing in line. I was in the process of floor tillering and it broke almost in two. I had planned on backing it with rawhide, and I am not sure if I had gone too far with the floor tillering or if I should have backed it before I started floor tillering. Some specifics on the bow, Cascara, Flat bow design, 58" NTN, I acquired the wood from vine maple bows. I seeking any advice you guys can give to help me for my third try at this. Does my design choice work for this type of wood? (thinking about trying osage or hickory really like a flat bow style) When should I apply my backing after roughing out or after floor tiller? 

[bubby]

What draw length are you trying to get, and do you have any pics of the last try

[mikekeswick]

Simple - before it breaks!!!!
I'd do it once the width profile is roughed out. No point in waiting longer if you think it needs a backing. If you just remove the bark on a stave without touching the wood underneath it won't need backing.

[George Tsoukalas]

If I am going to back I do so after long string tillering and before its first stringing with the short string.

If your stave broke while floor tillering there are other issues. That is... you forced it, it broke at a knot,etc.

Tough to say w/o pictures.

Check my site.
http://georgeandjoni.home.comcast.net/~georgeandjoni/index.html
Jawge

[PEARL DRUMS]

I add it right after the profile is roughed out and mostly done, before any bending on the floor. But I mostly use rawhide when I have to and don't trust the blank to bend without it.

[Pat B]

I added a rawhide backing on the bow I just posted; "Farm Hand".  this was a good stave with few issues with it but since it was going to be used by many I decided to add the rawhide. The bow was fully tillered with only some weight loss needed when I backed it.
 Usually I'll back a bow at about first brace.

[Blllkns]

Thanks everyone for your responses a lot of good advice. I think I might have forced it during floor tillering like George said. I was going for a 61" NTN with a 28" draw length. Not a 58" NTN like I said earlier. The bottom limb was 28" and the top limb was 29". Again thanks for the advice I think I will be adding the rawhide after I rough it out on the next one. I will post some pics when I figure out how to shrink them fit (new computer). 

[bradsmith2010]

if it broke during floor tiller,, you were to aggressive or the wood was bad,,
be careful when heat treating to straighten,, you can damage the wood if you try to bend to much,, and it is not hot enough to bend,,
I would suggest go easy on that for your first bows,,,, once the bow is hot,, you have only a few seconds to make the correction,,