Proper Care and Feeding of Pneumatic Tools

Pneumatic tools are to aircraft technicians as scalpels are to surgeons: They are essential ‘tools of the trade’. Yet despite this fact, some technicians either neglect or mishandle their air tools. It can be something as small as using the same compressed air supply to drive paint guns and air impact wrenches; risking lubricating oil leaching into the paint and ruining the next 737 refinishing job. Or it can be as big as tossing precision pneumatic tools around like baseballs, with the concrete shop floor serving as backstop.

Of course, the aviation industry isn’t the only one where pneumatic tool abuse occurs. “Having a pin put in my broken hand, my orthopaedic surgeon asked his nurse to turn on the nitrogen tank used to operate his air drill,” recalls Karl Matis. He is vice president of HECAT Inc., known in the aviation business for its HECAT pneumatic heat exchanger flushing equipment. “Thinking she was opening the bottle, she cranked up the pressure regulator,” Matis says. “When the drill did not work, the doctor jumped up and opened the bottle himself. When he pulled the trigger, the drill immediately screamed with rpm and disintegrated scattering shrapnel everywhere. Luckily no one was injured by debris.”

Back to aviation: What constitutes the proper care and feeding of pneumatic tools? Here’s some answers that will keep your air tools humming along for years to come.

Handle with Respect
Pneumatic tools are meant to be used repeatedly in harsh environments. This is why pneumatic tool manufacturers build their products out of hardened metals, with enough resilience and toughness to keep working day in, day out.

This said, even the toughest air tool has its breaking point, warns Jay Johnson, Mac Tools’ product manager for power tools. Sometimes breakage occurs because a tool is being asked to do too much. Other times, a properly used tool will fail due to years of wear and tear.

“The most common things that break or get damaged on ratchets and impact wrenches are anvils,” Johnson tells AMT. “Anvils often wear out and simply need to be replaced when they break. They’re always under heavy torque, which leads to steel fatigue.

“Gears get damaged on tools like drills, grinders, and ratchets when the user puts too much load on the tool,” he adds. “Pressing too hard on a grinder or hand tightening a fastener with a ratchet after the ratchet torque has maxed out puts a lot of stress on the gears.”

To make pneumatic tools last, the rule of thumb is to always use the right tool with the job. Don’t try to make smaller impact wrenches do the work of larger models. Otherwise, they will break sooner simply due to repeated overstressing.

In the same vein, respect that each tool has its wear limits. Take note of the manufacturer’s hour ratings for a given tool, and keep track of its actual usage. This does not mean that you have to note every time a tool is used, but you should record when a tool enters service, and forecast when it will need to be checked for servicing and/or overhaul.

Finally, if you want your pneumatic tools to last forever, Karl Matis offers these three words of advice: “Never use them.”

Handle With Care
In a perfect world, air tools and concrete floors would never meet. In the real world they often do, either by being dropped or tossed by careless technicians. That’s not all: “I’ve heard of tools getting run over by cars or forklifts on shop floors,” Johnson says. “It’s not uncommon.”

Any time a pneumatic tool suffers this kind of shock, its internal mechanisms can become misaligned and/or broken. The result can be wrenches that don’t turn, or compressor lines that leak. Whatever the damage, once it has happened, it has happened. Sometimes a pneumatic tool’s workings can be repaired, but sometimes they can’t.

The rule of thumb: Always have a safe resting place for pneumatic tools handy to the job site. By having this, technicians can put down the tools as needed, without dropping them on a concrete floor. If need be, put some kind of shock-absorbing padding around the resting place, to protect any tools that may slip off by accident. “It also helps to put ‘rubber boots’ on tools that are vulnerable to impact,” Johnson says.

On a larger scale, never toss pneumatic tools. It doesn’t matter if you were a star Little Leaguer or if you could have attended Notre Dame on a football scholarship. Don’t toss those tools!

The Importance of Oiling
It may seem like a no-brainer, but pneumatic tools require regular oiling and lubrication. Without this degree of care, the parts inside will start to grind against each other. Eventually, the tool will erode itself into uselessness.

Amazingly, “we’ve seen many tools at our repair center that have never been oiled: Never,” says Johnson. “This actually happens, even though almost all the air tools we sell say ‘oil daily’ right on the housing. All technicians know the need for grease and oil in automotive applications, yet a few of them don’t see the need in their air tools!”

“For all air tools, a lack of grease and oil probably accounts for most damage,” says HECAT’s Matis. “The only other factor that consistently causes damage is water in the air line.”

When you do oil your air tools, be sure to use the lubricant recommended for the job. As well, be sure that the oil doesn’t get all over the tool, seeping onto rubber and other components that need to stay oil-free. Whatever you do, don’t get oil in the air line!

One last piece of advice: “Oil tools daily at the end of the day,” Johnson urges. “The inner components of air tools are often made of steel and will rust easily. By oiling the tool at the end of the day, then running it for a few seconds, the oil will stay in the tool overnight protecting it from moisture.” Adds Matis, “For our use of company-owned assembly air tools; we require a few drops of air tool oil daily, and a tear down, inspection, and cleaning quarterly.”

Keep ‘Em Clean
Like oiling, being told to keep pneumatic tools clean seems obvious. Yet tool manufacturers often see pneumatic tools that have failed due to dirt buildup and water-caused corrosion.

In many cases, cleaning is a simple matter of wiping grime and moisture off the tool as needed. However, if an air wrench falls into a puddle, don’t just wipe it off and keep working. Instead, take steps to ensure that the inside is properly dried and relubricated, as directed by the tool’s service manual.
In the same vein, make sure that pneumatic tools are regularly stored in clean, dry containers. Protect them from moisture and shopfloor dirt, especially when not in use.

The Bottom Line
Take care of your air tools, and they will take care of business for you. Whether you are a shop floor technician, a foreman, or a general manager, this is the most important truth about the proper care and feeding of pneumatic tools.

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