By Steve Veroneau and Michael Springer
Specs and Tester's Tester Comments
As a builder in the Washington, D.C., area, I spend a lot of time with a nailer in my hand and, of course, a lot of time dragging an air hose around the jobsite. It was an eye-opening experience for me to try out the current generation of hoseless (a.k.a. cordless) nail guns, both framing and finish; it's an impressive array of capable tools, whether they are powered by gas fuel cartridges or by rechargeable batteries. After a few months of testing, I came to the conclusion that we are inching closer to a time when air compressors will be a thing of the past. I'm convinced that we are already at that point with finish nailers and, hopefully, are on the threshold of a great leap forward with framing guns, too.
Overall, I tested a dozen tools. Framing nailers (all of which are gas-powered) include the Hitachi NR90GR (round-head), Hitachi NR90GC (clipped-head), Max GS683RH (round-head), Max GS683CH (clipped-head), Paslode 900420 (clipped-head), Powers W3-21FRH (round-head), and the Powers W3-34CDH (clipped-head).
The finish nailers include the battery-powered DeWalt DC618KA (16-gauge angled nail) and Senco CF41 (15-gauge angled nail) and the gas-powered Paslode 900600 (16-gauge angled nail), along with the gas-powered Paslode 901000 brad nailer (18-gauge straight brad) and the battery-powered Senco CF25 brad nailer (18-gauge straight brad).
How They Work
The gas-powered nailers (all the framers and the two Paslode finish nailers) work much like any other internal combustion engine, relying on a controlled explosion to move a piston. When the nose is pressed onto the work, fuel is carefully metered out into the combustion chamber and mixed with air by an internal fan. When the trigger is pulled, a spark plug connected to the tool's battery ignites the mixture and the resulting rapid expansion of gas forces the piston and thus the driver blade downward. These separate steps are why bump-firing is not an option with gas-powered nailers. After the nail is shot, the fan continues to run as it removes exhaust gases from the combustion chamber. This cycle can be repeated a few times per second, but if the chamber gets too hot from rapid usage, combustion strength is affected and nails may be under-driven. When this happens, the nailer must be allowed to cool down before its next use. This is the basis of why gas-powered nailers are not considered true production tools and provides the challenge for their next generations.
Ongoing fuel expenses are another consideration with these tools; gas canisters cost between $5.50 and $8.50, depending on the brand, and are good for 1,100 to 1,200 shots. The nailers' small rechargeable batteries (6 volts to 7.2 volts) are good for 4,000 to 5,500 shots per charge, depending on the model.
The DeWalt and Senco battery-powered finish nailers operate with a flywheel and clutch system, and their larger batteries (14.4 volts to 18 volts) do all of the nailing work. A motor spins a flywheel as the trigger is pressed and when its speed is sufficient a solenoid briefly engages a mechanical linkage between the flywheel and the driver. This is why bump-firing works with battery-powered driving–the flywheel is just kept in motion.