Grinding wheel having core body coated with impermeable coating

A grinding wheel including: (a) an annular core body which includes a multiplicity of aggregate particles and a resin bond that holds said aggregate particles together; (b) an abrasive layer which is disposed radially outwardly of said annular core body and which includes a multiplicity of abrasive grains and a vitrified bond that holds said abrasive grains together; and (c) an impermeable coating which is formed of a synthetic resin, and which is disposed on said annular core body.