Quick Answer

Resin pads are worn when they stop cutting, glaze over, or leave consistent scratches - even if they still look like pad. Replace them when the floor does not get smoother after two passes, the pad surface looks shiny instead of gritty, or you see new scratch marks appearing. A set of diamond resin pads shows wear as the diamond layer thins to the backing; once the backing shows through, the pad is finished. Do not try to squeeze extra square meters out of worn pads - they scratch the floor and cost more in re-work.

Visual Signs of Wear

Stop the grinder and look at the pad under good light. Fresh pads have a matte, gritty surface covered in visible diamonds. Worn pads look glossy, smooth, or loaded with concrete dust. The diamond layer wears down to the Velcro backing.

• Glazed surface - pad looks shiny; diamonds are worn flat.
• Loaded surface - pad is caked with gray paste; clean it first.
• Exposed backing - Velcro shows through; pad is dead.
• Uneven wear - edges worn, center new; machine pressure is off.

Performance Tests

Visual checks can be misleading. Run these tests:

Why Worn Pads Are Dangerous

A worn pad does not stop cutting gently - it starts burnishing. That locks in old scratches and makes the floor look hazy instead of glossy. Worse, a glazed pad can leave random scratches that require dropping back two grits to remove. Replacing a set of pads costs USD 50-100; re-polishing a bay costs USD 500+.

A triangle-segment pad shows wear best: the triangles wear down, and when the diamond layer is flush with the triangle base, replace the pad.

When to Replace vs Clean

• Loaded with dust - brush with a pad cleaner or run on an abrasive brick.
• Glazed on soft concrete - dress on an old concrete test pad.
• Diamond layer half gone - keep using; it still has life.
• Backing showing - replace immediately.
• Leaving scratches - replace; do not try to clean.

For high-gloss final passes (1500/3000), use a fresh white resin pad - even slight wear kills mirror gloss.

Frequently Asked Questions

Q: Can I use a worn pad at a coarser grit?

A: No. A worn 800 pad does not become a 400 pad. It just burns the surface. Replace it.

Q: How often should I inspect pads?

Every 250 sqm, or every time you change grit. A quick visual check takes 30 seconds and saves hours of re-work.

Q: Are pad lifetimes printed on the package?

Manufacturers list expected sqm, but real life depends on concrete hardness. Use the visual and performance tests as the source of truth.

Q: Should I replace all 3 pads or just the worn one?

Replace all three on a head together. Mismatched pads leave arc patterns. Buy pads in matched sets.

Conclusion

Worn pads are diagnosed by performance, not calendar. Stop, look, run two passes - if the floor is not getting smoother, replace them. JOY TECH supplies matched resin pad sets in all grits; keep spares on site so a worn pad never stops the job.