New nail guns don't need a compressor

(ran HC HP editions)

For almost all of history, slapping two pieces of wood together has been numbingly slow and laborious, a painfully primitive process of pounding on a steel spike with what amounts to a club. Modern hammers with brightly colored high-tech handles, contoured grips and polished heads haven't helped much, but deliverance arrived in 1968 with the invention of the pneumatic nail gun.

Although the first models were clunky, expensive monsters, the device has evolved into a light, portable hand tool that pops nails into wood faster than most people can think. Best of all, nailers do so without denting wood, smashing thumbs or putting more money in the pockets of physical therapists.

This Old House contractor Tom Silva was one of the first residential carpenters to get the nail-gun bug in the 1970s. "I was watching an ad on TV, and I noticed a gun that shot nails being used in a factory," he recalls. He tracked down the manufacturer, who lent him a compressor and a couple of guns.

"We were able to frame the last half of a three-story apartment complex in a third less time than we'd spent hand-nailing the first half," Silva says.

Power nailers aren't merely faster; in many cases, they're better. A nail gun can punch a fastener into place in a single 800-miles-an-hour shot. The wood, caught in a high-tech ambush, has no chance to wriggle or resist.

Gun-fired nails penetrate old, iron-hard framing that bends hammered nails. There's no quaking and shaking: Plaster stays put; wallboard doesn't pop. A day's work doesn't create more.

Until recently, every nail gun required an air compressor and a length of hose. A failure of gun, compressor or hose, and it was back to swinging clubs.

The biggest aggravation, it turned out, was the hose. If it wasn't getting snagged _ in a doorway, on a lumber pile, around a sawhorse leg _ then it ended up an inch short of the target, like a dog straining on a leash.

From laptop computers to cell phones to the battery-powered tools that have swept the building trades, people crave portability and the freedom that comes with it. Freedom came to nail guns in 1986, when the Paslode Corp. introduced a nail gun that functions without hose or compressor. The gun is powered by internal combustion, just like the granddaddy of all portable machinery, the gasoline engine.

Pulling the Paslode's trigger releases MAPP gas (methylacetylene propadiene) from a disposable fuel-cell cylinder and injects the gas into the combustion chamber. Simultaneously, a spark detonates the mix and plunges a piston against the nailhead, driving it home in a lightning-quick stroke.

Paslode makes its Impulse gas-powered guns in two versions: a framing nailer and a smaller model for finish work. The smaller gun gets about 2,500 shots per $7 cylinder, the larger gun 1,200.

Both versions operate similarly. Insert the fuel, snap on a rechargeable battery, load a strip of collated nails, and you're in business. The 6-volt battery, which operates the spark plug and a tiny fan, is good for about 4,000 shots between charges.

With any nail gun, hoseless or otherwise, simply squeezing the trigger won't send steel spikes flying through the air. Before a gun will fire, you must press its nose firmly against a hard surface to release the safety.

Pressing down the nose of the Impulse also kicks on the fan, which mixes air and fuel in the combustion chamber, then cools and clears the chamber after firing. Pushing down the nose of the Impulse takes more force than a compressed-air gun needs _ 12 pounds vs. 6 _ And the tool emits a firearm's crack rather than a pneumatic's pop, so ear protection is needed.

The bright orange plastic Impulse is 1 to 2 pounds lighter than its metal pneumatic brethren, and it hooks easily onto a tool belt.

Last year, Porter-Cable began manufacturing gas nailers called Bammers: a framer, two finish guns and a crown stapler for assembling cabinets and holding insulation. All use MAPP gas in a cylinder similar to the Paslode's, but they operate without fans, motors or batteries.

A pressure-sensitive piezoelectric crystal, similar to that in a gas barbecue grill, generates the spark. The air and fuel are mixed and exhausted as the tool is plunged, so cocking the gun requires 23 pounds of push.

The Bammer shoots two nails a second, the Impulse shoots three and pneumatic nailers can deliver five. For a pro like Silva, extra effort and weight can make a day longer.

For a homeowner who uses a nailer occasionally, the Bammer is a pick-up-and-go tool that cuts down on recharging time. The Bammer requires very little maintenance. Its ignition system is designed to last for about 70,000 shots and to be replaced by the owner.

"It's time for a new one when you have to pull the trigger three or four times before it fires," Dennis Huntsman of Porter-Cable says.

Gas guns aren't about to make Silva's trusty pneumatics obsolete, but they fill a certain niche. "If we have a small backyard job or maybe some high nailing up on a roof, we'll throw the gas nailers on the truck," he says. "Also, if we're running through a house, nailing up trim here and there, those guns are nice to have. They're handy. No question about it."

For more information, call Paslode at (847) 634-1900 or Porter-Cable at (800) 487-2840.