I've been hanging drywall for about 30 years. Although I've had up to 16 employees, in this shaky economy I'm down to four. Together we're hanging about 2,500 12-foot sheets of drywall per year. Between big jobs, we keep busy by repairing drywall damaged by roof leaks, which are common on our stormy coast.
About five years ago, we started using Senco's autofeed screw guns, which have a built-in magazine and drive plastic-collated screws that come 50 to a strip. Collated screws cost almost twice as much as bulk screws, but I figured the labor savings would more than compensate.
The cordless tools allow maximum mobility when working on scaffolding and ladders.
First we tried Senco's 18-volt model DS275-18V. Losing the cord was great, but the tool generated only 3,000 rpm and started stair-stepping the screws as its nicad batteries ran down. The easiest way to sink the high screws and remove misplaced ones was to use a separate screwdriver. Also, the tool didn't have the inline grip found on traditional corded models, and it took a firm push to drive each screw, which was tiring. The spring-loaded depth gauge would sometimes stick and had to be retracted manually.
So we ditched the cordless model in favor of Senco's corded autofeed model DS200-AC. This gun generates a slightly faster 3,300 rpm and eliminates the stair-stepping, but has all the other drawbacks of the cordless version. Still, it's much faster than hand-feeding screws, so we've continued to use it.
For the past six months we've been testing two Hilti autofeed kits that pair an SD 4500-A18 18-volt lithium-ion drywall screw gun with an SMD 50 magazine. The compact kit (item #03474879) includes two 1.6-amp-hour batteries, a charger, and a contractor bag. The other kit (item #03468904) includes two 2.6-amp-hour batteries, a charger, and a plastic case, though you can get it with the contractor bag instead. Hilti has since replaced the 2.6-amp-hour batteries in that kit with 3.3-amp-hour ones, but we haven't tried them yet.
Although the SD 4500-A18 was introduced in late 2009 and is billed as the first cordless drywall screw gun capable of serial production, we had never seen one in action. For us, the kits have proven to be revolutionary.
Like standard corded guns, the core tool has a pop-off nosepiece, an inline grip, and a lock-on button.
Minus the autofeed magazine, Hilti's gun mimics a traditional corded model. It has a rubber-coated inline grip that makes the tool feel like an extension of your hand, a two-finger trigger with a lock-on button, a pop-off nosepiece, a 1/4-inch hex chuck and bit holder, and a removable top-mounted belt hook. But it generates up to 4,200 rpm, which is faster than many corded models; has a super-quiet clutch; and uses directional venting to help keep dust away from your face. It also has an extra belt hook that can mount to either side of the base.
The batteries have a built-in LED fuel gauge that lights up for a few seconds when you press one or both of the battery-release buttons. Thanks to these gauges, we're never inconvenienced by a dead battery. The LEDs also continuously track the progress as the batteries charge; you can confidently stop well short of a full charge to finish a job or secure a drywall patch.
To convert to autofeed, you install the Phillips bit included with the magazine (top) and then snap on the magazine in one of 12 positions. You remove the magazine by pressing the release buttons and pulling it off (middle). The magazine's depth gauge is set by pushing the orange button on top and sliding the gauge until it shows the desired screw length; it's fine-tuned with the thumbwheel (bottom).
To install the magazine, you simply remove the gun's nosepiece and bit holder, insert the Phillips power bit included with the magazine, and then snap on the magazine in your choice of 12 positions. The magazine takes standard plastic-collated drywall screws from 1 1/8 to 2 inches long. You load strips by threading them through the magazine from back to front until the first screw aligns with the pointer or the end of the plastic strip meets the exit point. If you go too far, you can press a release latch and pull the strip back into position (our Senco guns force you to pull the strip all the way through and start over).
To set the magazine's depth gauge, you push a button on top and slide the gauge until it indicates the desired screw length, fine-tuning if necessary by turning a thumbwheel. You can remove the magazine in a second by squeezing the two release buttons and pulling it off.
Pressing one or both of the battery-release buttons activates the LED fuel gauge for a few seconds.
In its standard configuration, the screw gun weighs 4.1 pounds with the compact battery and 4.8 pounds with the full-size one. With the magazine attached it weighs 4.7 or 5.4 pounds - or no more than the average high-performance 18-volt drill/driver.
So far, we've driven more than 40,000 collated drywall screws (1-1/4-inchers and 2-inchers) with the two Hilti guns, and we're still using the two Phillips bits included with the magazines.
The cordless freedom has been wonderful, especially when we're working on ladders, scaffolding, and stilts. At full throttle, the 2.6-amp-hour battery delivers more than two hours and the 1.6-amp-hour battery about an hour of runtime. They recharge in 30 and 20 minutes, respectively, so we never outpace the charger. (The new 3.3-amp-hour battery now shipping with the full-size kit should deliver about 25 percent more runtime than the 2.6-amp-hour battery and take 48 minutes to recharge.) We like the big battery for its longer runtime, but often use the small one for screwing off a lid or in the afternoons when our arms are getting tired. To prevent harmful deep discharge, the tools shut themselves off before completely draining the batteries. They're also supposed to shut off to prevent overloading or overheating, but that has yet to happen even after going full-bore for hours.
The autofeed magazine appears to be flawless. Its spring-loaded depth gauge requires no lubrication, compresses with ease, consistently drives screws to the proper depth, and leaves a nice dimple. Even with the magazine attached, the gun is so streamlined that you can lay it against the wall at inside corners and drive screws straight into a narrow backing. Being able to rotate the magazine is helpful for squeezing into tight spaces.
The fully equipped tool stands upright on the full-size battery, but not on the compact one.
When the magazine is attached and loaded, the gun can stand upright on the large battery, but it tips forward with the compact battery. So far, we've knocked one fully equipped gun off a second-floor balcony, dropped another one 6 feet onto concrete, and even kicked the tools out of our way, all with no harm done.
The roomy contractor bag holds the screw gun with the magazine attached, plus other tools and accessories.
My crew prefers the soft case to the plastic one because it holds the screw gun with the magazine attached, along with other tools and accessories. I tend to fill the bag with so much stuff I have to dig for the gun, so I use the plastic case, even though I have to detach the magazine to fit it in. The plastic case also keeps the tools drier in my pickup bed.
The Bottom Line
One of my co-workers doesn't like the color red. Otherwise, we have no complaints about these kits. They're not cheap - about $380 and $500 - but we figure each tool saves us about an hour of labor per day over the Senco corded autofeed guns we'd been using, and therefore would pay for themselves in less than two months. Also, you get a one-year warranty for wear and tear on the gun, a two-year warranty for wear and tear on the batteries and charger, and a lifetime warranty for defects. That's reassuring for a tool that could drive more than 750,000 screws per year on some commercial job sites. We're definitely converting.
Josh Overlin owns Chetco Drywall in Brookings, Ore.