I am fixing two bows right now. One was in a house fire and something fell on it, the only thing not broken was the bamboo. This was a belly break. I use a hypodermic syringe full of urac and was able to inject the glue deep into the ends of the broken area.
I coated all the pieces with urac and put my first clamp right on the break with each subsequent clamp applied on each side of the break forcing the excess glue toward the outer edges of the break.
After the glue cured I put a lateral sinew patch over the break using Elmer's wood glue. After this band aid dried I used back sinew for a wrap around the crack, also using Elmer's wood glue.
This picture shws just how bad the break was. From the the handle, deep into the limb and out the belly.
This one shows the sinew wrap over the ends of the break. There is another layer of sinew under the wrap you can't see in the picture.
Urac and sinew should hold this bow together. This is the worst break I ever tried to fix. If it doesn't make it I will be surprised.