Senco's new Fusion trim nailers operate unlike any drive system you've seen before and represent a giant leap forward in hose-free technology. As in pneumatic models, a cylinder-housed piston creates the force to drive fasteners, but the system uses a captive volume of nitrogen to pressurize, shoot, and repressurize over and over in a closed loop. The tool's motor applies force on the upstroke to pressurize the piston, so the driver shoots down the instant the trigger is pulled, just as it does with a pneumatic nailer. That's why the company bills the Fusion trim nailers as the first "cordless pneumatic" tools on the market. To understand the mechanism better, check out the first-rate animation of the drive system on Senco's website (

I've used gas-canister and battery-powered flywheel-type trim nailers in the past, but I always find myself going back to pneumatics because of their reliable functionality. As much as I love the concept of not being tied to a hose and compressor, other hose-free tools I've worked with have either been ergonomically clumsy or required routine cleaning and the regular purchase of costly fuel cans, so I have remained tethered to a hose.

Because Fusion nailers deliver performance more like that of pneumatics, however, experienced users may be more comfortable with them. The new drive system's ability to shoot a nail the instant you pull the trigger is a real boon. This is something gas nailers can do too, but it's not an option for flywheel tools unless you leave the motor running constantly in bump-fire mode. As for bump-firing – not an option with gas nailers – the Fusion shoots about one nail per second. This is on par with flywheel tools, but noticeably slower than pneumatics.

15-Gauge Finish Nailer

I liked the FN65DA right away because its appearance and feel are very similar to those of my everyday 15-gauge nailer. The front-heavy shape and bulky battery of other hose-free trim nailers I've used were replaced with a sleek tapered head and a flat, unobtrusive, compact lithium-ion battery pack. The tool feels very well-balanced, so even though it's on the heavy side at 6.6 pounds, its handling felt fine. Rubber material – similar to that on the handle-grip surfaces – on the front and top of the tool serves as bumpers to protect both the tool and any cabinets it may run into.

Setting the depth-of-drive is done by spinning a dial on the front of the tool. A nice depth gauge located under the dial clearly shows the relative depth setting, which ranges from just flush with the surface to 1/4 inch countersunk.

The Fusion had no problem driving nails at the desired depth into everything from hemlock to oak. In my torture-testing, the tool shot 2-1/2-inch nails through 3/4-inch ipe into a 2-by but would not counter-sink them; 2-inch nails countersank just fine. And this extreme testing was the only time I experienced a nail jam.

The tool shoots standard 15-gauge angled nails from 1-1/4 to 2-1/2 inches long. Cutouts in the magazine let you see the nail lengths you're shooting. The magazine is easily removed via a lever on the front of the tool that makes clearing a jammed nail easy. A dry-fire lockout shuts down the tool when there are only five nails left.

The Fusion is equipped with a hook that can be moved to either side of the tool and that adjusts from a belt hook out to a wide rafter hook.

An LED headlight doubles as an error light that turns off when the tool has timed out and requires the trigger or safety contact to be released and depressed again before a nail will fire. You have three seconds to pull the trigger after holding down the safety contact in sequential mode, and three seconds to depress the safety contact after holding the trigger in bump-fire mode. After three seconds the light goes out and you have to start either sequence over again. This function is part of the electronic safety mechanism, which cannot be defeated the way mechanical safety switches can. However, the headlight is very dim and doesn't show up in daylight. Even in a dark area, it doesn't really help guide your nailing, especially since the lit area ends about an inch away from the nose.

A weak headlight is no big deal, but I was disappointed with the clumsy safety contact design. The contact tip is 3/4 inch wide – much too big for a finish nailer. A narrower surface would certainly make nailing on profiles more accurate. As it is, the contact tip obscures the sightline to the nose, and the nails are difficult to place with precision. I suffered blowouts along a countertop edge and had to resort to lining my shots up by sighting a spot on the contact tip, since I couldn't see the nailer nose.

Another feature I found hard to get used to was the off switch. If left the tool in either the sequential or bump-fire-mode position instead of "off," the battery would discharge overnight. The manual warns of this, but I decided to learn the hard way by arriving at several job sites with a dead tool. Adding greatly to the confusion was the fact that early-production batteries like mine, after running down with the switch on, would still read full on the battery gauge. Senco says it has since fixed that issue.

The kit comes with only one battery, partly to keep the cost down (a second battery costs $100) and partly because Senco believes users won't outpace one battery. With an average capacity of 274 nails per charge in our trials with 1-3/4-inch nails, this is cutting it close. And of course you have to remember to charge the battery every night for busy workdays. I would rather just use a battery until it needs to be charged and then pop in a second one, instead of short-cycling the battery constantly, but this luxury would cost me another hundred bucks. The other way to manage the charging is to check the onboard battery gauge regularly and charge it during a convenient break from nailing. According to Senco, the Fusion battery will charge 80 percent in the first15 minutes, and finish charging within 45 minutes.

18-Gauge Brad Nailer

The FN55AX shoots a full range of brads, from 5/8 to 2-1/8 inches, and has the same selective fire, depth-of-drive, and headlight features as the 15-gauge tool. The only major feature difference is that the magazine does not pop off for jam clearing.

I didn't spend as much time with this tool because samples were hard to come by early on, but I had enough trigger time to get a good feel for it. The first thing that struck me was its weight. At 6.3 pounds, it weighs more than twice as much as my pneumatic brad nailer. The hose-free convenience and mobility are great, but adding extra pounds to such a small tool makes it more tiring to use and takes away some of the convenience. For punch-list work or small jobs on site, though, the grab-it-and-go nature of the tool makes it the obvious choice – as long as the lone battery is charged.

The tool's balance and grip are pretty good, but the extra weight and height are noticeable when you try to line up the nose for finesse shots like thin trim returns. The head of the tool isn't too bulky or front-heavy, as it was on previous battery-powered nailers, and the sightline to the tip is excellent. The flimsy protective cap on the safety contact moved around in use and could stand to be made out of a tougher – or at least thicker – material. As for power and performance, 2-inch brads stood proud in the 3/4-inch ipe, but 1-1/2-inch brads countersunk well. Like the 15-gauge nailer, the tool could bump-fire reliably at about one shot per second.

The Verdict

The Fusion tools definitely belong in the winner's circle, based on their ability to shoot nails instantly, but the technology hasn't yet passed the test of time: The biggest question this conservative tester has is how long the pressure-charged drive system will last. In an interview, a Senco spokesman claimed that the tool should outlast competitive technologies by performing twice as long as a gas trim nailer and three times as long as the flywheel types before needing any parts maintenance. He added that Fusion tools have been tested to 100,000 nailing cycles before needing any service. When the nailers do wear out, the pressurized drive and reset mechanism can be replaced as a single $149 part.

My second question is whether the Fusions are worth the hefty price tag.

If you're already equipped with air tools and most of your finish nailing work is done either in the shop or on large multiday field projects, the answer is probably no. If, on the other hand, you do a lot of small jobs, work in high-rise buildings, or are in the market for a second trim setup now, my answer would be yes.

As a complement to my pneumatics, both Fusion tools serve a valuable purpose as go-to tools for punch-list work and small installations, but I for one would not swap out my air nailers for battery-powered tools just yet. It's nice not being tied to a hose when up on a ladder or when you have to jump around from the lower level of a house to the upstairs – but reliable old pneumatics will still be a mainstay of the full-time cabinetmaker's and trim carpenter's business for a while longer.

David Getts is an architectural woodworker, remodeler, and author. He owns David Getts Design in Seattle.

Note: A third Fusion tool – the FN65RHA 16-gauge angled-magazine trim nailer – will make its debut in 2011.

Price: $449
PRICE: $399