Random orbit sanders make finer dust than any other woodworking tool. The abrasive runs at 10,000 to 12,000 RPM and produces particles as small as 0.5 microns. Those particles stay airborne for hours. Breathing them over months causes real lung damage.
A shop vac connected to your sander is not optional. It is the difference between a healthy shop and one that will cost you later.
How Dust Collection Works on a Sander
Random orbit sanders have two dust collection components:
- A vented sanding pad with holes that align with holes in the sanding disc
- A port on the top or side of the sander body that connects to a shop vac
Suction from the vac pulls air through the disc holes, through the pad, and out the port. This captures dust at the point of creation, right where the abrasive meets the wood.
This only works if you use a vented sanding disc that matches your pad's hole pattern. A solid disc (no holes) blocks airflow and you capture nothing, even with a vac connected.
Port Sizes by Brand
| Brand | Port OD | Key Models |
|---|---|---|
| Milwaukee M18 | 32mm | 2648-20, 2836-20 pad |
| DeWalt 20V MAX | 32mm | DCW210B, DWE6423K |
| Makita LXT 18V | 36mm | XOB01Z, BO5041 |
| Makita XGT 40V | 36mm | GBO01Z |
| Bosch PROFACTOR 18V | 35mm | GEX18V-2CN |
| Festool RO 150 FEQ | 27mm | 577017 |
| Festool ETS 125 EQ | 27mm | 576014 |
| Ryobi ONE+ | 32mm | PCL206B, PBLSRV01B |
| Ridgid 18V | ~36mm ID, measure to confirm | R8606B |
| Metabo HPT 18V | 35mm | SV18DGLP4 |
What Vac to Use
Any shop vac with at least 5 amps and a HEPA filter works. The HEPA filter is not optional for sanders. Standard paper filters let particles below 30 microns pass through. Sanding dust is mostly particles below 10 microns. You need HEPA (0.3 micron rating) to actually capture what you generate.
For finish sanding on hardwoods or exotic wood, use a Festool CT extractor. The CT MINI or CT MIDI filters to 0.3 microns and has a self-cleaning filter. The suction is matched to Festool sander ports for near-perfect capture.
For rough and medium sanding on a budget, a 5 to 9 gallon shop vac with a HEPA filter cartridge upgrade ($15 to $20) is fine.
How to Connect the Vac
- Find your sander's port diameter from the table above.
- Find your shop vac hose inner diameter (usually 1-7/8 inch for standard US vacs).
- Get an adapter from port to hose. Use the GulpDust configurator to find the right size.
- Push the adapter over the sander port. Push the vac hose over the adapter.
- Turn on the vac before you start sanding. Keep it running until you lift the sander off the workpiece.
Sanding Tips for Better Capture
Press the sander flat against the surface. If you tilt it, the pad edge lifts and dust escapes from the sides.
Move slowly. A fast pass throws more dust sideways before the port can pull it. A slow, controlled pass gives the suction time to capture each particle.
Use a consistent grrit progression: 80, 120, 180, 220. Jumping from 80 to 220 leaves deep scratches. Each step removes the scratches from the previous one. Fewer passes at each grit means less total dust generated.
For finishing coats (220 and finer), use a HEPA extractor. The finer the grit, the finer the dust, and fine dust is the hardest to capture with a standard filter.
What If I Do Not Have a Vented Pad?
Most random orbit sanders come with a vented pad. If yours is worn out or you want a better one, replacement pads are available from the tool manufacturer and from aftermarket suppliers. Match the hole pattern (5-hole vs 8-hole vs 6-hole) to your sanding discs.
Festool sanders use a proprietary hole pattern with more openings than other brands. Festool-compatible discs are available from multiple manufacturers at lower cost than genuine Festool discs.