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Working
on Air
A lot of old-house owners may not have thought much about air tools because until recently, they were pretty much restricted to nailers and staplers manufactured for big-job contractors. That's a reasonable application, since the compressors that drive air tools are most efficient when they work in brief spurts that match the rhythm of nailing and stapling. These tools can be used in more limited ways on old houses, for framing additions, for instance, or putting up miles of interior moulding. Yet there is a larger array of air tools out there for restorers to tap, including chisels, wrenches, drills, sanders, washers, sandblasters, grinders, and painters. Several manufacturers have long offered standard duty tools for home use, while others are redesigning nailers and compressors to be more friendly and affordable for nonprofessionals. Some people say that once they've started using air tools they are positively addictive. They want more tools with fancier features. A compressor has a billion uses, says Steve Jordan, OHJ contributing editor, who often recruits one for sandblasting and adding texture to wall paint. They're great for blowing dust away for painting prep, especially for hard-to-reach projects like radiators. What is compressed air? Most of us are familiar with large industrial compressors, the type that enable jack hammers to make that earsplitting racket at construction sites. Compressors have a long list of other commercial uses, from firefighting to operating rooms to recovery of maple syrup sap. Air tools in general have a lot of advantages. The added energy source makes them more powerful and faster than similar electrical tools. (In the case of nailers, there are no similar tools.) Because the motor isn't in the tool itself, they are about 20 percent lighter and have fewer moving parts to wear out. Once you've invested in a compressor to run them, in some cases for less than 200 dollars, they can be half as expensive as the equivalent electric tool. Most home-use compressors are powered by electricity. Gas-powered models are usually larger, intended for construction crews who lack access to electric power, and they can't be used indoors. Since your electricity source can be many feet away at the end of your air hose, you can more safely use the tool in wet areas, such as for repairing gutters. What Do I Need to Know? Some manufacturers say 2.5 horsepower is more than enough power for a homeowner who will use the compressor only now and then, and that an electric motor this size is as much as a 115-volt, 20-amp circuit can handle. Campbell-Hausfeld, however, says the 5-horsepower compressors in their new Home Workshop Series will run on a standard circuit. Look beyond the horsepower of the compressor, which is often given as peak horsepower, the level at which the motor will burn out. You don t need to know how powerful your compressor's motor is so much as how much air it can deliver to your tools, and you can get compressors that deliver more air at a given pressure with the same horsepower. Manufacturers rate air tools by maximum pressure in pounds per square inch (psi), but more tellingly, by delivered air, or cubic feet per minute (CFM) produced at a given pressure, usually 90 psi, the pressure at which most small air tools run. Some use Standard CFM (SCFM), noting that air temperature, barometric pressure, and relative humidity affect CFM. One maker recommends multiplying your tool's required SCFM by 1.25 to determine how powerful a compressor to buy. (Keep in mind that you may want to add tools later, or if you have a second handyperson in the house, run more than one tool at once.) Other considerations: Size and style of compressor-- You can hand-carry the smallest portable compressors, sometimes in shapes described as hot dog or pancake, while slightly larger styles are mounted on wheels. Portable tanks are as small as four gallons weighing just over 32 pounds. Chores such as sanding and grinding require a heavier, stationary model. Tanks with a vertical, rather than horizontal, design take up less space. Hoses-- The standard air hose is 3/8". The longer your hose, however, the lower your CFM. You should probably go up to a 1/2" hose if you work 60' or farther from the compressor. For close-quarters work in your garage, you can buy a hose that recoils. Bells and whistles-- Air contains water that collects in the compressor tank, so users need to drain it after each use to prevent rust and corrosion. Some compressors offer moisture filters and automatic tank drains to make this job easier. Thermal overload protection and after coolers guard against overheating. The Tools-- Over the decades, manufacturers have developed several general families of pneumatic tools, each comprising many specialized tools to serve the needs of a particular craft or industry. Here's just a sampling of them and how you might use them on an old house. Construction and cabinetmaking-- Sure, nailers are faster than hand-nailing, but fans say that's only the beginning. They eliminate the need to countersink nails. They free a hand to hold whatever you're working on. While heavier than a hammer, they're less physically punishing. Users say there are no dings from misplaced hammer blows, fewer splits, and easier toe-nailing, although handling the tools takes some getting used to. Careless use will result in kickback or jamming, and poor design can blow exhaust in your face. Most brands have two alternate modes of delivery. Bump, bounce, or contact firing lets a nail fly when the tool touches your target. Sequential nailing lets you control the speed with a trigger. Framing nailers use only large nails. One advantage in an old house: They set up fewer vibrations than hand nailing so that if you re reframing a sagging wall, you re apt to have less cracked plaster on adjacent walls or ceilings. Air-driven nails are often coated with adhesive, which is melted by the friction of nail meeting wood and holds better. Roofing nailers help get your house back under cover faster. Most have a base you can adjust to various shingle exposures, so you get nails in the same place in each one. Finish nailers drive 15- or 16- gauge nails from 3/4" to 2 1/2" long and are more versatile, for interior trim or joinery, for instance. Brad nailers, the baby of the family, are useful for making cabinets, attaching small pieces of trim and face frames, and clampless gluing. Staplers are handy where the work won't show: plywood soffits, cabinet backing, floor and counter underlay, upholstery, latticework, picture frames. Craftsman now offers one they say will countersink in hard wood. Sanders for smoothing and shaping your wood come not only in rotary disc versions, but some manufacturers also make oscillating sanders that mimic the back-andforth motions of hand sanding. Machine and metalworking Air-powered metal grinders, chisels, and rustscaling tools find ready application in repairing and refinishing steel windows and iron fencing. Pneumatic impact wrenches designed for driving nuts and bolts with controlled twisting power have even been used for production bolting of heavy timber frames. Masonry Trow & Holden of Barre, Vermont, makes pneumatic chisels for sculpting and other stonework that restorers find ideal for removing old mortar before they repoint stone or brick walls. These tools don’t stir up view-obscuring dust or cut into adjacent courses like grinders do, and work roughly three times as fast as a hammer and hand-held chisel. Painting-- Air-powered spray painters have been retooled in recent years to be more environmentally friendly, with high-velocity low-volume (HVLV) systems that overspray less paint. Manufacturers sometimes call them “airless” sprayers. However, users still complain about overspray and difficulty with latex paints gumming them up. Most major air-tool sellers are now touting gravity-feed sprayers. These have a clear paint container above the nozzle that lets you see how much paint you have left and, ostensibly and logically, delivers the paint to the nozzle with less waste.
GLOSSARY CFM-cubic feet per minute psi-pounds per square inch Delivered Air Cut-in and cut-out pressure
SUPPLIERS CRAFTSMAN (800) 377-7414 (catalog includes tools from other manufacturers), www.sears.com/craftsman. CAMPBELL-HAUSFELD (866) 247-6937 www.campbellhausfeld.com DE WALT (800) 433-9258 www.dewalt.com HITACHI (800) 546-1666 www.hitachi.com INGERSOLL-RAND (800) 247-7378 www.air.ingersoll-rand.com PASLODE (800) 682-3438 www.paslode.com PORTER-CABLE (800) 487-8665 www.porter-cable.com TROW & HOLDEN (800) 451-4349, (802) 476-7221, in Vermont SENCO (800) 543-4596 www.senco.com |
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