Although cordless tools are all the rage among nouveau DIYers, for many hobbyists and advanced wood- and metal-workers, air powered tools are still the way to go. Once you’ve bought the basic infrastructure — a compressor and supply lines — you can buy an air-powered tool that will perform almost any job. What’s more, the tools, which have no electric motors or internal power sources, are lighter, more responsive, and generally less expensive than their conventional counterparts. Here’s what you’ll need to get started…
The centerpiece of any air tool collection is a compressor and its air tank, which are often a combination package. Consumer models are powered by 120V line current, and most have oilless electric motors to run the compressor. Heavy-duty users such as framing carpenters and painters tend to prefer oiled motors; a major difference is that oilless motors can operate in any position, while oiled models must be resting within a few degrees of horizontal. Another difference is that heavy users will find that a compressor with an oiled motor will outlast the equivalent oilless model if properly maintained. And last, oiled models are generally quieter than oilless compressors.
When choosing a compressor, you must first what size you’ll need: light users who will use a compressor mostly to run low-pressure tools like sprayguns or to inflate toys and balls will find a small, pancake style such as the Campbell-Hausfeld FP2028 Compressor (oilless, one gallon capacity) or the torpedo-shaped Senco PC1010 (1-gallon, 1-hp) both suitable and portable. Be aware, though, that their maximum output pressure may be insufficient for some tools. The DeWalt D55140 (1-gallon oilless) boasts a maximum 135-psi tank pressure, which may work for small jobs requiring heavy-weight tools.
Step up in size and pressure capacity to a larger pancake or a stack style like the stacked DeWalt D55151 (2.5-hp, 4-gallon oilless) or the Makita MAC2400 (2.5-hp, 4.2-gallon oilless). In pancacke style consider the Porter-Cable C2002-WK (6-gallon oil-free) or the Bostitch BTFP02011 (6-gallon, 2-hp, oilless).
If you plan to run continuous-flow tools like grinders, sanders, and the like or operate two tools simultaneously, such as a pair of framing nailers? You’ll want a larger capacity tank like the DeWalt D55168 (15-gallon capacity) or the Puma PK5020; a 20-gallon capacity oil-lubricated model that can operate on either 120V or 240V. Both of those are still to some extent portable. The biggest compressors like the Campbell Hausfeld VT6275 (60-gallon) tend to be oiled varieties and so massive that they are designed for a permanent emplacements, such as a shop or factory.
There are also a few small-capacity oil-lubricated models: a fan favorite is the Makita MAC700 (2-hp, 2.6-gallon tank). It’s based on a high-output, large-bore pump that allows faster recovery in use, yet is quieter than an equivalent-sized oilless pump. The low-speed pump draws lower voltage, making it ideal for residential circuitry that might “brown out” under the load of a large oilless compressor.
When choosing a compressor, look for one that has sufficient reserve pressure capacity: a tank pressure of 150psi has 30psi of reserve pressure when operating tools like framing nailers at 120psi. Except on the smallest compressors, you can expect a multiple-output manifold so you can have two or more hoses and tools running simultaneously. You need a pressure regulator and gauges that report both output pressure and tank pressure. If a model offered for sale does not have a petcock for draining condensation out of the tank, don’t buy it: the tank will rust far too fast.
A compressor-user’s rule of thumb: if the motor is running more than half the time you’re using your air tools, you need a bigger compressor.
Supplying Air to Your Tool
You won’t get anywhere without a supply line. Most users prefer the light weight and ease of handling of coiled lines, at least over the last ten or twenty feet of the run. Be aware, though, that their smaller diameter occasionally causes pressure problems for big-load tools like framing nailers, hammer drills and impact wrenches.
The basic supply line is a good-quality 3/8- or 1/2-inch rubber hose with 1/4-inch ends to connect the NPT-threaded air connectors. The most common lengths available are 25 and 50 feet. Nylon lines are generally less expensive, but in my experience they’re stiff and difficult to work with, especially when they’re cold. I use a plastic line only at the compressor end if connecting two lines, and a rubber line or coiled line at the tool end.
When it comes time to wrap up my supply hoses, I’ve found that one of these Worldwide Cable Mega Clamps makes it easier to keep the hoses from unrolling and tangling. That’s a great deal of convenience for just a couple of bucks. And, of course, a set of connectors (and a roll of teflon tape) are in order, since regular air hoses don’t usually come already equipped with them.
If you use your air tools in a humid or dusty environment, you should protect them from dust and moisture (and maybe even particles of rust) in the air lines by using an in-line air filter like this one made by Ingersoll-Rand. Go ahead and run your tools for just one day and then look to see what kind of gunk has collected in the reservoir – and then think of that going through your nail gun or grinder!
Air tools need to be oiled every day that they’re in use, and sometimes more often. A slick way to keep lubricating oil circulating through your tools is an in-line oiler like this one from Bostitch. This little attachment drips a teensy drops of oil into that air line while a tool is in use. An in-line oiler should not be used on lines that will be used for spray painting, so I always plug mine into the base of the tool instead of the head of the line.
Good lubricating oil is also an essential. Buy oil that’s specifically designated as air tool oil, since it’s formulated for the tool’s normal operating conditions – sewing machine oil and 3-in-1 lubricant just won’t stand up to that level of pressure, and they have the wrong viscosity.