A pneumatic nail gun is a simple power tool and helps you drive nails accurately into the workpiece (usually wood) to join the parts. They are widely used in building and construction, carpentry work, woodworking, home improvement, and DIY project.
The way the nail guns work is simple.
Every one of us uses a stapler when we want to staple a bunch of paper and we do it so effortlessly. In many ways, the working of the stapler resembles that of a nail gun, and of course your finger pressure is sufficient to drive a staple pin into the paper.
However, nailers are usually powered by compressed air or batteries and they are a lot more powerful. You must learn how to use it safely before attempting to work with it independently.
Parts of a Pneumatic Nailer
First, let’s see the important parts of a nail gun which will help you to understand the working principle of the tool easily.
1. Compressed Air Connection
As the name suggests, a pneumatic nailer is powered by compressed air. You need to connect the hose from your air compressor to the air inlet of the tool and usually, this connection will be of a quick coupling type.
In some designs, the air inlet connection on the nail gun may be of a swiveling type for more flexible movement.
2. Nose Tip
This is located at the bottom end of the nail gun, from where the nail comes out.
The nose tip has a safety feature. You cannot drive a nail into the wood unless you keep the nose tip pressed on the location of nailing. This helps eliminate accidental and unintentional firing of the nail.
3. Trigger
The trigger of your nail gun controls the movement of the compressed air either above the piston (when you press the trigger) or below the piston (when you release the trigger).
The trigger will have a safety catch that eliminates the accidental and unintended firing of the nail.
4. Magazine
The magazine of your nail gun holds the strip of nails and positions a nail under the drive piston blade.
The design of the magazine can vary according to the type of nailer (straight vs. angled magazines) and the capacity of the nail gun. The coil nailers have a round canister-style magazine that can hold a large number of coil nails.
The magazine may have a small window to show you the number of nails left in it.
5. Depth Adjustment
This can be in the form of a knob or a lever and allows you moderately increase or decrease the driving depth of the nail (without changing the pressure of the compressed air).
6. Modes of Driving the Nail
Apart from the regular mode of driving the nails (sequential or one by one) some nail guns may have a feature called bump firing mode. The bump mode allows you to drive a nail by just pressing the nose tip at the location of nailing, without the need of pressing or releasing the trigger.
7. Exhaust (outlet)
The compressed air that is used for actuating the drive blade, exits through this port.
In many designs, there can be a lever or knob to blow off the wooden particles from the work area and you can view the nailing spot clearly. Also, there will be an arrangement to open the area above the nose tip to clear out the jammed nails. The arrangement can be in the form of a simple latch or screws.
Working Principle of a Pneumatic Nailer
A pneumatic nail gun has to perform its task in two stages:
- Drive the nail into the wooden surface held against it and
- Load (place) a nail under the piston rod. Each manufacturer may have its own design for doing these works.
Your pneumatic nail gun is powered by compressed air and it can get the compressed air directly from a compact air compressor or from an air receiver tank (connected to a larger industrial air compressor).
The working principle is very simple. There is a piston sliding up and down in a cylinder and a drive blade is attached to the bottom side of the piston. The spring-loaded magazine ensures to place a nail under the piston rod.
When the trigger is pressed, compressed air flows above the piston and pushes the piston downwards and the blade drives the nail into the workpiece.
At the end of the stroke, the compressed air is released. When the pressure of the air below the piston becomes more than that above it, the air pushes the piston back to its original position. The magazine places another nail below the piston rod. Now, the pneumatic nail gun is ready to drive the nail once again.
How the Nail Gun Works?
Step-1: Initial Position
Connect your pneumatic nail gun to the compressed air source. Read your owner’s manual and ensure your air source can supply the required volume of air at the required pressure.
The compressed air enters the holding area or the reservoir inside the nail gun. From the reservoir area, the compressed air enters the chambers surrounding the cylinder and also on both sides of the plunger valve (the plunger valve is above the piston and it is in closed condition).
The pressure of the air below the piston is more than the air pressure above it, hence the piston stays at the top of the cylinder.
There is a nail under the piston rod.
Step-2: Trigger Pressed
When you pull the nail gun trigger (follow the safety precautions) it prevents the entry of the compressed air from the reservoir into the chambers surrounding the cylinder. Now the pressure of the air below the plunger valve is more and the plunger valve opens to let the air into the cylinder top (above the piston).
Now the pressure of the air above the piston is more than that below it, hence, the piston is pushed down.
Step-3: Nailing Stroke
When the compressed air moves the piston down, it pushes the piston blade to drive the nail into the wooden board below it.
Step-4: Return
The final step of the cycle happens when you release the trigger. The used compressed air in the cylinder goes out through the tiny holes on the cylinder wall and enters the bottom of the cylinder through the slots.
Now, the plunger valve at the top of the cylinder is closed and there is no compressed air above the piston. In this situation, the pressure of the air below the piston (at the bottom of the cylinder) is more than the pressure of the air at the top of the piston, hence, the piston along with the piston rod is pushed up to its original position.
As the piston moves up, the air is vented out at the top of the nail gun.
The magazine pushes another nail to the location under the piston rod and the nail gun is ready for driving the next nail.
Depending on the type of pneumatic nail gun, the pack of nails can be a straight strip type or coil type, and the nails are held together by glue, paper collation, etc. The shape of the nail holding device (or magazine) is different for strip type and coil type packs. It is the job of the magazine to place the nail under the piston rod and when it is driven out, replace the next one in its place.
Placing a nail under the piston rod can happen with a simple spring force (strip type) or by an air-driven plunger (coil type).
Nailing Methods: Bump vs Sequential
There are two types of driving the nails,
- contact or bump driving and
- sequential driving.
Depending on the design of your nailer it may have the provision for only the sequential driving method, or both sequential and bump driving methods.
In contact or bump driving, you can drive the nails continuously simply by pressing (bumping) the nose tip against the wooden surface. On the other hand, for sequential driving, you must have the trigger pulled and also the nose tip pressed against the wooden surface.
Nail Gun Safety
Even though the operation of your pneumatic nail gun is quite simple, it can cause serious accidents if not handled properly. Please consider the following safety guidelines.
- Work with a known carpenter at least for a couple of days and learn how to use the pneumatic nail gun safely, before you attempt to use it independently.
- Please verify if you need any permission from your local authorities for keeping and using a pneumatic nail gun in your hobby shop.
- Read the owner’s manual thoroughly and understand it. Remember, each manufacturer may have its own modifications from the standard design.
- Wear the safety gear suggested by the manufacturer of the pneumatic nail gun, including safety glasses. Do not wear loose apparel.
- Understand the safety features given in your nail gun.
Possible accidents while using a pneumatic nail gun.
Always mind your hands when working with a pneumatic nail gun. Your hands should never come in the path of the nail movement.
Double Fire: The incident of double firing may occur when you try to locate the nose tip accurately on the wooden workpiece. Since your finger may be on the trigger, unknowingly the trigger may be pressed twice, resulting in driving two nails instead of one.
When you use a heavy-duty framing nailer, it may give a recoil force when you drive the nail, and this force may move the nail gun towards your body. Take necessary precautions to overcome the recoil force.
Conclusion
If you bought a power nailer for the first time, you may be full of enthusiasm and want to start using it straight away. However, it is always better if you can work with a professional carpenter or a friend (who is already using a pneumatic nail gun) for a day or two and learn how to use it safely, before attempting to use it independently.
Dan Miller is a professional toolmaker with extensive experience in the metalworking and tooling industry.
An avid DIY enthusiast and passionate hobbyist woodworker, Dan shares his expert knowledge here.