Nail guns use electric solenoids, pneumatic rams, or combustion-driven pistons to fire nails at speeds exceeding 200 miles an hour (321 kph), so any attempts at repairing these tools must involve a great deal of caution. Before attempting a nail gun repair, it is important to unplug the tool from the electricity or compressed air supply, or remove the ignition source if it is a combustion unit. One common issue with nail guns is a jammed feeding mechanism, which can sometimes be repaired by disassembling the tool and removing the excess nails that have become stuck. Pneumatic nail gun repair often involves a leaking o-ring, so if one of these tools malfunctions a seal kit is often required. Electric nail gun repair can involve malfunctioning solenoids, though in some case electrical connections can break and need to be soldered back together.
The first tip to keep in mind when attempting nail gun repair is to ensure that the driving mechanism is not charged or loaded. A nail gun that is jammed or failing to fire may suddenly work during examination, which can cause injury if precautions are not taken. An electric nail gun should be unplugged or have its battery removed, and a pneumatic unit should be disconnected from its source of compressed air. Combustion nail guns should also be disabled before disassembly, though the exact process of doing so can vary from one tool to another.
Many nail gun malfunctions involve the tool jamming, which can occur when too many nails are fed into the firing mechanism at once. This can often be fixed by opening up the tool and removing the jammed nails. In some cases the firing pin may be knocked out of alignment, in which case it has to be put back into place with a pair of pliers or another tool. If the nail gun continues to jam after this repair has been performed, then there might be an issue with the loading mechanism. Other items to inspect include the return spring and any type of safety catch that might impede the firing pin.
Pneumatic nail guns rely on compressed air to operate, so any leak within a tool can cause it to not fire at all. If a pneumatic nail gun vents air when the trigger is pulled, one likely cause is a bad o-ring. These o-rings can be obtained separately, but it can also be a good idea to find a model-specific seal kit before attempting pneumatic nail gun repair. If a kit is available, it will have all of the necessary seals. Air tools can often benefit from a few drops of oil every so often, though that may be insufficient to repair a nail gun that is no longer firing at all.