My felt wheels is bloated and misshapen, what happened?
Felt material is a porous natural wool felt and will have the tendency to swell when in lengthy contact with water. Under normal circumstances on a bench grinder or lathe there isn't enough continuous water contact to cause the wheels to swell significantly. If left on the lathe or bench grinder while not in use or if an inordinate amount of water is used with the wheels they may swell more than normal and lose it's original shape.
We generally recommend spinning the wheels dry on the lathe after each use and store them in a dry location.