Will this need a backing?

[monterey]

Here are a couple photos of a red oak board (more like a stick) that I'm hoping to fashion into a 35 to 40 lb bow 72" long.

Would this grain orientation call for a back or??

[Roy from Pa]

With the run outs, I would say yes.

[macbow]

I agree, once you cut out the shape there will be more run outs.

[monterey]

Thanks, I was unsure but at the same time thought it might be advisable!  Part way to the profile and will start scooping out the belly tommorrow

[Black Mockingbird]

If that was 3" wide you would have enough width to lay it out along the slight diagonal grain lines and it would be fine unbacked. You wood just follow and cut out to the grain lines and not lay it out to the straight edge.

Actually you might still be able to get a 66-68" stave outta that and make it an unbacked bend in the handle bow.

[Red Tailed Hawk]

I would back it to be safe.

[monterey]

The board, as is is only 1.5" wide.  I'm sorta following the Baker tutorial in the appendix of TBB IV.  What I'm doing different (so far) is planning for a non bending handle.  I can still go to a bend in handle design but am undecided at this point.  So much going on have not been able to begin reduction of limb thickness yet.  Maybe this eveining.

Thanks to all of you who have offered advice!