Reply by renners

If you are determined to use the OSB up on this project, maybe you should make it with a face frame. You could put a solid back on it that will take fasteners for hanging – with a piece underneath the unit attached to the wall so it can sit on it and take the weight. Use a 2×1 lipping for the front of the shelves to stiffen them up, put dividers in so you don’t have long spans which will sag under the weight, screw/glue on 3/4×3/4 supports inside the carcase around the sides and back and screw/glue the shelves to that. Shouldn’t give you any problems.

-- Do or do not, there is no try