Quick Answer

Resin-bond diamond pads with a closed (non-foam) back, available in 3" (80mm), 4" (100mm), or 5" (125mm), are designed for wet polishing concrete. Wet-specific pads resist water degradation, shed slurry well, and run cooler than dry pads. Standard resin pads with velcro backing work wet on angle grinders and planetary machines — the key is water flow to the surface and pads rated for wet use.

Wet vs Dry Pads

Feature	Wet pads	Dry pads
Water tolerance	Designed for constant water	Water degrades the bond
Heat	Run cool	Run hot, need airflow
Finish quality	Crisp, clear gloss	Good, slightly softer
Dust	None (water suppresses)	Heavy — needs extraction

Choosing Pads for Wet Work

• Size: 3" pads for grinders and tight areas, 4"/5" for larger floors and planetary machines.
• Bond: resin bond for polishing stages (200–3000); metal bond for aggressive grinding (50–200) — wet-capable metal segments are also available.
• Backing: hook-and-loop (velcro) fits most machines; some 5" pads use a center hole or M14 thread for direct mounting.
• Grit range: buy a full 50–3000 set so you can step without switching pad types.

For concrete and terrazzo wet polishing, 3-inch diamond resin floor polishing pads and 5-inch diamond resin polishing pads cover the most common machine setups.

How to Wet Polish Correctly

• Keep a steady water supply — enough to carry slurry away, not a flood.
• Use a water ring or shroud on the grinder to contain splash.
• Start at 50–100 grit for leveling (metal bond), then resin 200→3000.
• Never let the pad run dry — a dry resin pad burns and smears.

Frequently Asked Questions

Q: Can I use regular dry pads with water?

A: Some resin pads tolerate water, but wet-specific pads last much longer and polish cleaner. Metal-bond pads can work wet or dry; pure dry resin pads degrade quickly with water.

Q: What size wet pads do I need for a concrete countertop?

A: 3-inch pads are ideal for countertop edges and tight radius work; 4-inch is a good all-rounder for flat tops.

Q: Do I need a special grinder for wet polishing?

A: You need a variable-speed grinder with a water feed or a wet polisher. Fixed high-speed grinders without water control overheat the pads.

Conclusion

Wet polishing concrete needs resin-bond diamond pads built for water, in the right size for your machine, stepped from 200 to 3000 with steady water flow. Choose 3-inch or 5-inch wet-rated pads and keep them wet for a clean, cool, dust-free polish.