What glazing is
Abrasive wheels are meant to break down slowly, exposing fresh sharp grit. When the surface loads with metal or the grit dulls without breaking away, the wheel becomes smooth and shiny — it stops cutting and starts polishing, which generates heat rather than chips.
Dressing restores the surface
A dressing tool — a star dresser, a diamond point or a dressing stick — removes the loaded layer and exposes fresh grit. It also trues the wheel back to round, which removes the vibration that a worn wheel develops. Two minutes, and the grinder cuts like new.
Replace the supplied wheels
The grey wheels shipped with almost every bench grinder are hard and coarse. A softer aluminum oxide wheel, white or pink, breaks down more readily and runs cooler — it is the single cheapest improvement to a bench grinder, and it is why the wheels are the first thing to plan to replace.
Dip, or use water
On a dry wheel, grind briefly and dip the tool in water often, before it is too hot to hold. If the tip changes color — straw, then blue — that metal has lost its hardness and must be ground back past the discolouration.
The questions welders ask
How do I know a wheel needs dressing?
It stops cutting and starts making sparks without removing metal, and the work heats up much faster than it used to. A shiny, smooth wheel face is the visual sign. If the grinder has also developed a vibration, dressing usually cures that too.
Can I sharpen without a wet grinder?
Yes, with discipline: coarse shaping on the dry wheel with frequent dips, then a fine wheel or a stone for the edge. The wet grinder removes the risk rather than the possibility — it simply cannot reach tempering temperature.
Last reviewed 2026-08-14
