By Martin Harris.

Spindle Sander Dust Collection

Most benchtop oscillating spindle sanders have a small 1-1/2 or 2 inch dust port under the table, and a shop vac is the best match for a port that size. A dust collector moves far more air, but a small port chokes it. Some fine dust will still escape at the sanding point, so add a simple hood or an air cleaner and wear a respirator for longer sessions.

This page covers the port sizes on common benchtop models, how I would set up a shop vac, hood options that help, and how to protect yourself from the fine dust. For other sanders, see my sander dust collection guide.

How a spindle sander makes and moves dust

An oscillating spindle sander has a sanding drum, called a spindle, that sticks up through the table. The spindle spins and also moves up and down. That up and down motion is the oscillation, and it spreads wear across the sleeve so you use more of the sandpaper. You press the edge of a curved board against the spindle to smooth it.

Dust is made right where the board touches the sleeve. On most benchtop models, the dust port connects to a chamber under the table. Air is pulled down through the gap between the sleeve and the table insert, the removable ring around the spindle, and out through the port.

That layout helps. The dust source stays in one spot, unlike a handheld sander moving across a panel. The weak point is that the air only pulls from below. Dust that flies outward or upward off the spinning sleeve can miss the gap and float into the room.

Port sizes on common benchtop models

Sources: JET JBOS-5 product page and manual FAQ; Shop Fox W1831 published specifications; WEN 6510T product page and retail listing. Check the manual for your exact model before buying adapters.

These ports are small, and that decides what you should connect. Air speed in a hose equals CFM divided by the hose's cross section area. CFM is cubic feet per minute, a measure of air volume. Air speed is measured in feet per minute, or FPM.

At about 4,000 FPM, a common duct speed for wood dust, a 1-1/2 inch opening passes only about 49 CFM. A 2 inch opening passes about 87 CFM. To push 350 CFM, a typical dust collector branch figure, through a 1-1/2 inch port, the air would have to move at more than 28,000 FPM. A dust collector's fan cannot build the pressure to do that, so most of its airflow never happens.

The pressure a fan builds to push air through resistance is called static pressure. Shop vacs and dust extractors build a lot of it and move a small volume. Dust collectors move a large volume at low pressure. A small port needs high pressure, which is why a vac fits here. My dust collector vs shop vac comparison covers this tradeoff, and my static pressure guide explains the term in more depth.

Setting up a shop vac

1. Match the hose to the port. Use a stepped rubber adapter or a hose cuff sized to your port. Wrap a loose joint with tape or use a clamp. A leak at the port pulls room air instead of air through the table.
2. Use the smallest table insert that clears the sleeve. JET includes four inserts with the JBOS-5 for this reason. A tight gap keeps the air moving fast right next to the sanding point. A wide gap spreads the same air over more area, so it moves slower where the dust is made.
3. Put a cyclone separator between the sander and the vac. Sanding dust clogs a vac filter quickly. A separator such as the Oneida Dust Deputy Deluxe drops most of the dust into a bucket before it reaches the filter. See my best dust separators and Dust Deputy vs Super Dust Deputy pages, or build your own with my DIY dust separator guide.
4. Use a HEPA filter in the vac. HEPA means the filter meets a defined standard of 99.97 percent capture at 0.3 microns. A stock vac filter can blow fine sanding dust right back into the room through the exhaust.
5. Set up automatic start if you can. A vac or extractor that turns on with the sander gets used every time. Many dust extractors have a tool outlet for this, and a remote or current sensing switch works for other setups.
6. Empty the bucket before it fills. Suction drops as the separator or vac fills, and a full separator starts passing dust to the filter.

If you are buying a vac for this job, my best shop vacs for woodworking and best dust extractors roundups compare the options. A dust extractor is a shop vac built for power tools, usually with a HEPA filter, a quieter motor, and auto start. My Festool dust extractor review covers one of the most common choices.

Hood options

The under table port catches dust that falls through the gap. A hood catches dust that flies off the sleeve above the table. A hood is any opening placed next to the dust source to pull that air in. OSHA's wood dust guidance says collection should sit as close as practical to where dust is made, and a hood is how you do that above the table.

The simplest hood is an open box behind the spindle at table height, with its back connected to a 4 inch dust collector branch. The open face points at the spindle. Because this hood has a wide opening, it suits a dust collector's large air volume. It works well alongside a shop vac on the under table port.

Air speed drops fast as you move away from any opening, so the hood has to be close to work. Keep its face a few inches behind the spindle and keep the opening no larger than you need. A huge opening spreads the air out and catches less. My dust collection hood guide covers shapes and sizes in more detail.

• With only a dust collector. Connect it to a hood behind the spindle instead of the small port. You will catch more that way than by forcing collector air through a 1-1/2 inch opening.
• With only a shop vac. Keep it on the port. A vac hose makes a poor hood because its small opening only pulls from a few inches away.
• With both. Run the vac on the port and the collector on a hood. This is the setup I would choose for long sessions.
• Leave room to work. A spindle sander job means moving a curved board around the spindle. Mount the hood so it does not block the board's path.

Protecting yourself from fine dust

Sanding makes the finest dust in the shop. Particles in the 10 to 30 micron range are visible and settle fairly quickly. Particles under 10 microns stay in the air much longer, and the smallest ones, 2.5 microns and under, are the ones that matter most for your lungs. On a spindle sander you watch the edge closely as you work, so your face stays near the dust source.

OSHA lists wood dust health effects including skin and eye irritation, allergic reactions, and asthma, and notes that certain hardwood dusts have been linked to nasal cancer. NIOSH recommends keeping total wood dust exposure under 1 mg per cubic meter over a work shift, which is much stricter than OSHA's general dust limit. My page on whether sawdust is dangerous explains these numbers. If you sand MDF edges, read is MDF dust dangerous too.

• Wear a respirator. Collection lowers your exposure, and a respirator handles the dust that gets past it. My woodworking respirator guide covers fit and filter ratings.
• Run an air cleaner during and after sanding. Room filtration catches what the port and hood miss. See my air filtration roundup, or build one with my DIY shop air filter guide.
• Clean with a vacuum. Sweeping or blowing off the table puts settled fine dust back in the air. My tips to reduce dust in a woodworking shop cover cleanup habits.

Related guides

A drum sander is a very different machine that needs a full size collector. See my drum sander dust collection guide for that setup. For how every tool fits together in a small shop, see my guide to dust collection for small shops.

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