Each month Pro Tool Reviews likes to break down the technology that we all… well, pretty much take for granted. This month we found ourselves using a fuel powered nailer and it suddenly occurred to us that this “simple” cordless tool was actually incredibly complex. Not content to simply take anyone’s word for it, we got one opened up and took a look at the internals.
That’s when we realized we were way in over our heads and decided to go straight to the source. We called Warren Corrado, product manager for Paslode, the company that invented the cordless fuel powered nailer.
Because I think it’s relevant, give me a second to describe the history of the pneumatic nailer. If you aren’t interested in this, it’s your loss – but feel free to skip to the next paragraph and we’ll talk more about the tech. Paslode claims to have introduced the very first pneumatic tool in the form of an upholstery tacker back in 1959. Other products were also introduced to handle pallet crating. But during the mid-80s Paslode was already starting to observe that hoses and such were cumbersome, particularly with stud wall and larger projects. That birthed the cordless Impulse nailer. But fuel powered nailers were another breed.
When replacing the air supply with a fuel cartridge, getting the piston to return back to the firing position was one of the biggest hurdles. Prototypes, however, revealed that the rapid heat changes created a vacuum effect which solved this problem. Call it a happy accident. Really, it’s very similar to a one cylinder combustion engine.
The Firing Process Broken Down into 9 “Simple” Steps
Here’s how the process works, when you break it down into steps: 1) press the tip against the work surface, 2) the system doses fuel into the firing chamber, 3) the upper cylinder is closed (like closing intake valves on a gas engine) and the trigger mechanism is released, 4) the fan starts up and mixes the air and fuel, 5) pull the trigger, 6) the battery generates spark at the combustion chamber head which ignites the fuel/air mixture, 7) This rapid expansion of gasses drives the blade down, which shears one nail off the strip and drives it in, 8) the thermodynamic gas effect sucks the driver blade and piston back up, 9) when the tool comes off the workpiece, the exhaust is vented and the fan continues to spin, prepping the chamber to take another drive at it.
What’s impressive is that this system is so effective. The same basic technology can work to drive nails as small as brads all the way up to 3-1/2″ framing nails. What makes the difference between reliability and a tool that doesn’t keep up is the electronics. A microprocessor, which also runs off the battery, makes sure everything is operating properly. It monitors the number of shots, the speed, and any faults.
Maintenance and Wear
On previous models, and up until 4-5 years ago, a large O-ring would seal the combustion chamber. This was the Achilles heel of the system and a major point of potential tool failure. This was replaced in newer models, so that the new fuel system uses a steel ring which increases durability, keeps the engine cleaner and removes a major fault point. Modern fuel nailers can drive around 50,000 nails between cleanings on average.
Keeping the engine clean is important (much like a vehicle) and pneumatic tools require oil on regular basis. The fuel used in this type of nailer already includes oil, however, so that step is removed from the regular use of the tool. When you clean it, only then do you need to add oil. This type of preventative maintenance maintains the tool over a long haul (this works out to around 10-15 minutes of downtime once/month for a heavy user).
Gas-powered cordless nailers aren’t the only game in town. There are battery-powered options, for example. But 18V and larger batteries add pounds to the weight of the tool while fuel + battery solutions give you greater energy density (the amount of power delivered per mass). Overall, the fuel powered nailer is an efficient and lightweight tool, given what it can do. So what’s in store for the future? Well, there are already fuel-powered framing, roofing, finish and brad nailers in addition to staplers. Perhaps more powerful and lighter tools (greater power-to-weight) and even further improvements in reliability and durability for the professional user are around the corner.