Surface breakage of a sound bar
If relatively heavy mallets (e.g., the old Allbright mallets) are used and played with high momentum, cracks may appear in the anodized layer and in the aluminum base. The sound bar can then no longer be used.
After sanding down the anodized layer, it becomes clear that the cracks extend all the way into the aluminum base. A bar with cracks like this cannot be repaired.
