Siding is finish trim. Granted, it's not the mahogany panels and crown molding you'll find in the governor's library, nor the corbeled cornice and facia adorning his roof, but it's a far sight removed from rough framing. Also, siding not only has to look good, it has to be tough enough to brave the elements and, in fiber cement's case, it even has to stand up to fire. So, the nearly invisible tacks and brads you see the trim guys shooting just won't cut it on the sunny side of the wall.

For a long time, exterior siding was a tool industry orphan and manufacturers tried to deal with it by tweaking their framing nailers. Years ago, you'd tell your nail supplier you'd just landed that big siding job. He'd hand you a couple of rubber bumpers that fit over the nose-safety of your framing nailer, telling you that the device made the tool a "flush nailer." Others would pull the driver out of your framing nailer, grind a 1/4-inch off, and return it to you with the same promise. And some would recommend turning your air pressure down to some absurd level and shooting really slowly.

None of these techniques worked very well. You either shot halfway through the siding or left nail heads sticking out. Actually, it was worse than that. In the course of nailing off one run of siding, you'd do both. So now you had to have your hammer in one hand driving in shiners, and a putty knife in the other -- filling holes. Siding-installation tools have come a long way, and nobody could be happier about this than I am. We just landed that big siding job.

Test Criteria

Our company, Framing Square in Albuquerque, N.M., builds multifamily projects in four Western states. We apply siding on buildings that must withstand Rocky Mountain winters. We tested eight siding nailers on 3/4-inch board-and-batten, rough-sawn cedar, 7/16-inch hardboard, and fiber cement horizontal lap siding. We were looking for tools that operated efficiently and smoothly across this spectrum of materials without diminished performance from one material to another. Also, we didn't want to perform a search-and-rescue mission to come up with a box of nails if we ran out. We wanted safe tools that have good depth-of-drive adjustments, are easy on the work, and feel as good in our hands after lunch as they did in the morning.

We tested the Duo-Fast CNP-60Y, the Fasco F45C-CN15W/PS-65 SS (CT), the Hitachi NV65AH, the Makita AN611, the Max CN565, the Porter-Cable Coil 250, the Senco SCN55S, and the Stanley Bostitch N64C. While the tools were in the mail we set up scaffolds at our sites in Snowmass, Glenwood, and Copper Mountain, Colo.

Nails

Collation. Siding nailers have a few common characteristics. Compared with "shoot a few, load a few" 60-shot framing nailers, these coil-fed tools are a different breed. Their round-drum magazines accept coiled rolls of nails containing 200 to 300 fasteners (depending on the nail size.) The coils come in two flavors: plastic-collated and wire-collated. We found that wire collation is far more durable than plastic. Our testers said that if a plastic-collated roll took a fall or got banged around, you might as well forget about using it. The nails are set in tiny grooves in a plastic strip and if they are jarred out of position, they will feed the tool incorrectly and jam the nailer.

Versatility. My crew travels, so we have a good feel for purchasing and repairing tools far from our home base. Specific fasteners may not be available locally, so although we prefer wire collations, we may have to use plastic. The ability to reload quickly and not have to search suppliers for tool-specific nails is important to us. The Fasco, Hitachi, Makita, Max, and Senco models accept both collation styles. Porter-Cable and Stanley Bostitch accept wire collations, and the Duo-Fast nailer only accepts Duo-Fast brand plastic-collated fasteners.

Performance. Seven of the eight nailers performed well in a controlled environment (with consistent siding and sheathing), shooting and setting nails in cedar, hardboard, and two thicknesses of fiber cement. Ironically, the Porter-Cable tool, which shoots the thickest gauge nails (up to .120), consistently bent nails in the fiber cement laps. The company is about to introduce the Coil 200, a new nailer that's more suited for fiber cement but was not available for this test.

Control

Depth-of-drive adjustments. This feature makes these tools perfect for siding. Depth-of-drive adjustment allows the operator to consistently flush-drive nails in walls where the sheathing material behind the siding may change and on jobs with different siding materials. For example, cedar is soft wood and cement siding is as hard as -- well, cement. It takes different amounts of force to flush-drive nails in those materials.

The best siding nailers have tool-less depth-of-drive adjustments that let the operator change settings on the fly. This is a very important feature because you'll likely run the same siding over the entire building, but may not shoot through the same substrate. Most projects we frame have plywood shear panels on the corners and a softer sheeting like gypsum in between. Four feet from the corner you may find the setting that let you flush-nail through siding is now blowing through siding and gyp-board and you need to adjust quickly.

The best depth-of-drive we saw is Makita's tool-less calibrated adjustment. It works like a charm -- smooth, easy, and well-designed. The Duo-Fast, Hitachi, Max, Porter-Cable, and Senco nailers each have good tool-less depth-of-drive systems, too. The Fasco and Stanley Bostitch tools require a wrench to make the adjustment. Tool-less adjustment makes great sense if lots of people run these tools, because there's no wrench to lose.

Select activation modes. Another important feature to look for is what we call "select fire." This feature lets the user switch from bump-fire to single-fire modes, which is very handy for assuring a single, solid shot when you're nailing up that delicate angled jobbie that took half an hour to measure and cut. Only the Fasco, Makita, and Max tools offer these modes. Fasco's works with a lever. It also has a red rubber cap that, when removed, locks the nailer in single-fire mode. It works well and might be good for new guys, but the problem is that the little red cap, like a wrench, is easily lost. In fact, we lost it.

The Makita and Max tools fire in different modes depending on how you use them. Hold the trigger, depress the nose piece, and you've got bump-fire mode. Depress the nose piece, then pull the trigger, and you've got single-fire mode. Neither tool will dispense a second nail when operated in a single-fire sequence.

The Duo-fast, Hitachi, Porter-Cable, Senco, and Stanley Bostitch nailers all come with standard bump-fire trigger mechanisms, but you can get conversion kits to switch some of them over to single-fire tools. Stanley-Bostitch ships its tool with the SEQ1 conversion kit. Porter-Cable and Senco will send you a retrofit kit free for the asking. Hitachi has a kit that can be ordered separately. Duo-Fast currently doesn't offer a single-trip trigger kit for the CNP-60Y because it's a new tool. The company says its policy is to make single-fire triggers available for all its tools, so one should be available for the CNP-60Y soon.

Exhaust. A tool-less adjustable air exhaust is a nice feature when you're nailing a piece down in the bottom corner and dust covers your face every time you fire. The Hitachi, Makita, Max, and Porter-Cable models all feature 360-degree, tool-less exhaust adjustments. The Fasco, Senco, and Stanley-Bostitch tools all require wrenches to move their deflectors.

Ergonomics

If you use these tools full-time, tool weight can really affect the way you feel at the end of the day. Our testers put these nailers into three categories: light, medium, and heavy. (Note: These are "empty" weights; add about 1-1/2 pounds for nails.)

  • Light: Duo-Fast, Hitachi (4.6 pounds); Max (4.9 pounds); Makita (5 pounds)
  • Medium: Fasco (5.3 pounds)
  • Heavy: Senco, Stanley Bostitch (5.8 pounds); Porter-Cable (6 pounds).

Not surprisingly, our testers immediately gravitated toward the slimmer, lighter nailers. The lightweight tools have more compact profiles that make them a lot easier to use in tight spots.

Safety Features

The Makita and Max tools come with trigger safety locks. When the trigger is locked, the tool can't fire. Also, Makita is the only manufacturer to include a belt hook for its nailer. Some might consider this a convenience, but I think of it as a safety feature. Coil nailers are ungainly and like to roll over when you put them down on the scaffold. The fact that 5 or 6 pounds of tool and nails could fall any time someone puts a nailer down makes me think a belt hook is a heck of an important safety feature.

Most of the tools we tested come with vinyl debris shields on their fronts. When the pneumatic ram sends out a nail, it also shears off and sends out little pieces of collation wire. A debris shield keeps the wire from going everywhere. The Duo-Fast and Stanley Bostitch nailers are the only tools that don't have shields.

Durability

No tools broke down during our tests and they all seem to be well-engineered, well-made tools. The Stanley Bostitch nailer has some exposed springs we wondered about, but presented no problems during the test. We were also a little concerned by the plastic nail canisters on the Hitachi and the Makita models, but had no problems with them either. Actually these canisters let you see you how many nails are left, which is a plus. There's nothing like monkeying to the highest point of the scaffold only to learn you're out of nails when you get there.

Max's maintenance-free end cap really got us excited. This is a self-cleaning filter that sits inside the handle. It allows air and oil in, but screens out dust and debris. When you unplug the tool from the air hose, the back pressure in the tool blows out the filter, ejecting any collected debris. Max claims this extends the tool life, and I believe it.

Service is another vital element for selecting the right nailer. You have to do your own legwork on this, but it's important. Even the best tool is going to break down once in a while, and it's nice to be able to drop it off with someone who has the parts and know-how repair it promptly. Check with the manufacturer for local support, or check with your local repair shops to see if you're buying a tool that is right for you.

The Envelope Please

Our testers ran these tools through their paces and couldn't find a bad tool in the bunch. But for our money, Makita is the first choice. The AN611 is light and has every imaginable feature, plus it's engineered and manufactured very well. Add to that a good price and this tool is hard to beat. However, the second-place tool almost did. The Max nailer is very solidly built and has many features we really like. The rest of the models line up like this: Hitachi, Fasco, Stanley Bostitch, Senco, Porter-Cable and Duo-Fast.

Michael Davis is president of Framing Square in Albuquerque, N.M., a large framing, siding, and trim company, and is a contributing editor to Hanley-Wood's Tools of the Trade.