Cut Porcelain Chip-Free With a Grinder and a Soaked Sponge
The Problem
Dry-cutting porcelain with an angle grinder chips the glazed edge, overheats the blade, and throws a cloud of silica dust. A wet saw solves all three, but renting or buying one for a handful of cuts is hard to justify — and some cuts (curves, cutouts mid-tile) don't fit on a wet saw anyway.
The Technique
- Mark the cut and support the tile on a stable surface.
- Soak a sponge and hold it against the tile at the cut line, so the line stays wet and water wicks into the kerf as the blade passes. Keep the sponge hand well clear of the blade's path, and re-wet the sponge as the cut dries it out.
- Cut with a continuous-rim diamond blade at a steady, unhurried feed. Let the blade cut at its own pace rather than forcing it.
The water does two jobs at once: it keeps the blade cool — heat is what causes chipping and blade glazing — and it binds the dust into a slurry at the cut instead of letting it go airborne.
Pro tip: If a diamond blade has already been glazed by dry cutting and cuts slowly, it can be restored — see the tip on dressing a glazed diamond blade.
Safety note: Water and a power tool are a real hazard together. Keep water away from the grinder's motor and vents, never submerge the tool, and plug a corded grinder into a GFCI-protected outlet — or use a cordless grinder. Wear eye protection; even with wet cutting, a respirator is cheap insurance around porcelain dust.