Quick Answer

Swirl marks on polished concrete come from single-disc buffing, dirty pads, or skipping a resin grit. Remove them by dropping back 1-2 resin grits, re-running the floor with clean resin pads such as triangle-segment resin pads in cross-patterns, then burnishing. Do not try to burnish over swirl marks - that locks them in. Most swirl is removed at 800 grit if you catch it before the 1500/3000 burnish stage.

Where Swirl Marks Come From

Swirl is a fine circular scratch pattern. On polished concrete it appears for three reasons: a dirty pad that picks up grit from a coarser stage, a single-disc burnisher run too fast, or a skipped grit where coarse scratches are not fully removed. The marks are invisible under overhead light but pop out under angled light.

• Single-disc swirl - circular arcs from a 17-inch buffer; drop back to 800.
• Cross-contamination swirl - pad carried over grits; use separate pads per grit.
• Grinding swirl - coarse metal pattern never fully removed; drop back to 150 metal.

The Fix Sequence

Identify the worst grit that shows swirl. If it appears at 800, drop back to 400 and run through 800 again. If it appears at 1500, drop back to 800. Always cross-hatch the repair. Use clean pads - a pad that has seen 400 grit will scratch an 800 floor.

Pad Choice for Swirl Removal

Soft, flexible pads cut swirl better than stiff pucks. A white resin pad at 800 grit is the standard swirl-removal tool - it cuts fine without leaving new scratches. Run dry with extraction, at low speed, in overlapping cross-passes. After removing swirl, switch to a fresh pad for the next grit so you do not re-introduce the pattern.

Preventing Swirl on the Next Floor

• Use dedicated pads per grit - never use a 400 pad at 800.
• Brush pads between uses to load out embedded grit.
• Inspect with angled light at every grit before moving up.
• Burnish at low speed (1500 RPM max) - high speed burns swirl into the surface.
• Keep pads clean; dirty pads are the number-one swirl cause.
• Change pads every 500 sqm even if they look fine - loaded pads swirl.
• Never use a burnisher to cut; it only polishes, and it burns swirl into soft surfaces.

For final swirl removal before handover, a wool burnishing pad at high speed with a little water polish compound pulls up the last of the micro-swirl.

Frequently Asked Questions

Q: Can I remove swirl with a burnisher alone?

A: No. Burnishing polishes the surface but does not cut scratches. You must drop back to a cutting resin grit first.

Q: Why does swirl show only at night?

Angled light (sunlight through a window, a flashlight on the floor) reflects the tiny scratches. Overhead diffuse light hides them.

Q: How often should I change resin pads?

Every 500-1000 sqm, or when they stop cutting. A glazed pad swirls the floor instead of polishing it.

Q: Can I fix swirl on a small area?

Yes, but feather the repair out 1 m around the spot. Spot fixes on polished floors leave a visible circle - plan to re-polish the whole bay if swirl is widespread.

Conclusion

Swirl is almost always a pad-hygiene or skipped-grit problem. Drop back one grit, run clean flexible resin pads in cross-patterns, and inspect with angled light. JOY TECH supplies the full resin pad set in 50-3000 grit; tell us where the swirl shows for a recommended repair sequence.