Here is an extreme example of a fix; I had a tip overlay come unglued on one side and crack my upper limb down about 6", the crack didn't go through to the belly. Dang, I was just in the finishing stages of the bow, I threw the bow in the dead bow pile.
About a year later and after back surgery I needed a low poundage bow to start shooting again. I thought "I wonder if I can salvage that bow"?
I narrowed the tips and glued in an overlay that was half the thickness of the limb at the tip and feathered it down to paper thing where it transitioned into the limb, I added a osage burl overlay on top of my patch. I use the old style Urac for glue.
Needless to say I was a bit apprehensive about shooting the bow but it stayed together, thousands of shots later it is still shooting with no problems.