A finishing nail gun is a power tool that drives finishing nails. It is used for quickly affixing trim pieces, such as moldings and paneling. Most such tools are air powered and can drive several nails per minute, making it a staple tool for finish carpenters.
There are many types of nails used during construction, including roofing nails, framing nails, and finishing nails. Framing nails are longer and heavier than finishing nails, both because they contribute to the structural soundness of a building and because they are driven through thicker pieces of wood. These nails generally require an entirely separate, more powerful tool. Tools that provide different cartridges for finish and framing nails — and that have adjustable power controls — are available but may be more expensive.
Finishing nails can be shorter and thinner because they are used to affix non-structural trim pieces. Such nails must, in fact, be thinner that framing nails because a heavier nail could cause a trim piece to crack or splinter. Finishing nail guns are made specifically to shoot these smaller nails. The nails are driven with enough power to affix the trim, but are not so powerful that the surrounding wood is damaged.
Most finishing nail guns are air-driven, meaning that they are connected to a separate air compressor by a hose. These compressors are available in different sizes and powers. The compressor uses an electrical supply to generate air pressure, which is then forced through the hose into the gun. When the trigger is pulled, the air pressure forces the nail into the wood.
Finish carpenters, who are carpenters who specialize in finish work such as cabinetry, trim pieces, and decorative paneling, often use a finishing nail gun, particularly when they are installing a lot of trim at once. Using a nail gun is faster, allowing them to complete more work in the same amount of time. Use of a finishing nail gun also eliminates the marks or dents that a hammer can leave on wood.
This tool also drives the nail deeply enough that the nail head is recessed below the surface of the trim piece, the desirable position for puttying and painting. To create this same effect by hand, a carpenter would need to carry and use both a hammer and a nail set, a tool specially designed to set the nail head below the surface. This means holding the nail and hammering it most of the way in, then placing the nail set and hammering it the rest of the way. A finishing nail gun, on the other hand, simply requires the carpenter to hold the barrel to the desired spot on the wall and pull the trigger.
As with any power tool, care should be taken when operating a finishing nail gun. Nails should not be loaded when the gun has pressure, nor should the barrel be pointed toward anyone or anything that could be injured or damaged. Air pressure also should be properly released whenever the tool is not in use.