If you’ve got a decent-sized compressor in your shop, why are you only using it to spray finishes, blow dust off benchtops, and shoot fasteners from a nail or staple gun? When you think of air tools, the impact wrenches and body grinders used in automotive and metal shops may first come to mind. But there are lots of sanders, saws, drills, routers and more that run on compressed air and are perfect for everyday tasks in the woodshop. Many of these tools are pneumatic versions of electric portable power tools. Yet air tools are more compact, simpler and easier to maintain, safer to operate (no chance of electric shock) and — best of all — are often more affordable than their electric counterparts. For example, a 1/4″ electric die grinder will set you back $100 – $150 or more, but you can buy a pneumatic die grinder for as little as $10 – $20. Production quality air tools made by companies specializing in pneumatics such as Sioux and Dynabrade cost more, but are built tough enough to handle the heaviest use and still last for decades.
If there’s a downside to using air tools, it’s that most have a powerful hunger for air, meaning you need a fairly large compressor to run them at full capacity. There are a couple of other issues to consider with air tools, although I don’t think either is a deal breaker. Although air tools are not significantly noisier than electric tools, the added clatter of a running compressor can create quite a din in a small shop. Also, the tools’ air exhaust tends to blow sawdust around, and if you work in a cold climate, this cool air blast can feel unpleasant.
Air Tool Operation
Regardless of the size and type of compressor you have, the setup for running air tools is basically the same. You’ll want an air filter/moisture trap and a regulator connected to the outlet of the compressor’s storage tank to clean and dry the air and adjust the pressure to match the tool’s recommended PSI. A flexible hose connects the compressor to the tool. When running air tools with higher standard cubic feet per minute (SCFM) demands, it’s best to use a 3/8″ I.D. air hose that’s 25 to 50 feet long. You can get by using 1/4″ I.D. air lines with tools that have lower SCFM requirements. If an air tool doesn’t come up to speed quickly or lacks power, switch to a larger diameter and/or a shorter hose.
Most air tools have lever-like paddles that control the airflow and switch the tool on and off. You can reduce the speed/power of the tool by putting less pressure on the paddle. Many tools also feature an air regulation knob, which lets you set the maximum amount of airflow (and thus the speed/power) with the tool’s paddle wide open.
Air tools need to be lubricated regularly to keep them operating smoothly: Simply apply a few drops of air tool oil (in a pinch, you can use 10-weight SAE motor oil) to the tool’s air inlet every day before use. For heavily used tools (or if you’re prone to forget oiling), fit an automatic oiler on the tool’s air inlet. When starting up a freshly-oiled tool, cover the air exhaust with a rag, as oil is apt to be sprayed everywhere. Because lubricating oil can contaminate air hoses and, subsequently, raw wood surfaces and spray-gun-applied finishes, it’s a good idea to designate one hose just for air tools.