Concrete Grinding Tips

This is the single most important decision in concrete grinding.

Soft concrete-Under 3000 PSI-Hard Bond  - resists wear from abrasive aggregate;

Hard concrete-Above 5000 PSI-Soft Bond - exposes fresh diamonds as surface dulls;

Quick rule of thumb: Soft concrete → Hard bond. Hard concrete → Soft bond.

Never skip grits. Each grit prepares the surface for the next.

1.16–30 grit-Initial preparation - flattening, levelling, coating removal;

2.40–60 grit-Levelling - remove scratches from coarse pass;

3.80–120 grit-Refinement - smooth surface for polishing or coating;

Start with the coarsest grit needed, then progress systematically. Skipping grits means deeper scratches remain, requiring additional passes and wasting time.

What to do: Use a calcium chloride test or electronic moisture meter before grinding. Allow at least 72 hours after cleaning or rain exposure before starting work.

Surface contamination is a silent killer of diamond tooling.

1.Oil stains-Penetrate up to 6mm deep-Chemical degreasing;

2.Paint layers-Heat build-up damages tooling-Coarse 16-grit segments;

3.Epoxy coatings-Bonds at 300-400 psi-Mechanical scarification;

4.Surface hardeners-Reduce efficiency by 60%-Water absorption test

Higher RPMs work better with softer bonds on hard concrete (above 4000 PSI).

Lower speeds suit harder bonds on softer surfaces.

Proper speed selection extends tool life by 30-50% while maintaining consistent results.

Never force the cut. Let the diamonds do the work.