Spool guns are like that little pocket on jeans. Everyone’s seen them, but only a few people actually know what their purpose is. In reality, knowing why and how to use a spool gun is essential for maximizing your welding arsenal and becoming an expert. Especially when trying a new process or material, knowing how and why to use a spool gun can be very important.

Why Use a Spool Gun

A spool gun is, in essence, a MIG gun with the drive rolls for the wire mounted directly to the gun itself. The main idea is that you’re reducing the distance the wire would normally travel from your machine to the gun. There are two main reasons why you’d use a spool gun instead of a normal MIG gun.

The first reason is if you’re working with wire made from a softer material, commonly aluminum. Aluminum wire can become deformed when it experiences any sort of resistance, which is bound to happen if you’re trying to push it through 5 feet of cable. If the wire becomes deformed, it won’t feed through the gun anymore and begin tangling itself inside the cable or around the drive rolls. Using a spool gun means the wire is only feeding a few inches, drastically reducing the chances of it becoming caught up.

Another common reason for using a spool gun is with welder/generators. Engine driven machines have gone a long way in size and weight, but they’re still quite big. Welders will often mount their welder/generator semi-permanently to a vehicle, meaning long cables are used to bridge the gap between the machine and the actual weld site. This presents a problem. If the welder/generator housed the drive rolls inside the machine like normal, it’d have to push the wire over an extended distance. This would result in the wire constantly getting caught or tangled. Because of this, most welder/generators don’t even have drive rolls. Instead, you’ll need to use either a spool gun or a wire feeder (a device that looks like a briefcase and goes in between your MIG gun and your welder/generator).

How to Use a Spool Gun

Actually using a spool gun is pretty simple, once you’ve got it set up correctly. Most spool guns work exactly like a MIG gun: just pull the trigger. However, getting the right gun and setting it up correctly is where most of the problems can occur. This makes it essential to know a few key tips.

The first one is very important: Your Spoolgun must be compatible with your welding machine to work. Unfortunately, there’s no “universal” spool gun standard. Every brand does their spool guns a little differently (even between different machines of the same brand). You must check which spool guns your machine is compatible with before you purchase, or your spool gun might be completely worthless. There are some welders out there who’ve Macgyvered work-arounds, but don’t be fooled, that’s a difficult and unrealistic solution that’s best to avoid by simply doing a little bit of research before you buy. If you’re thinking about a wire feeder suitcase instead of a spool gun, they also will only work with compatible machines.

Another thing to consider when buying a spool gun is the weight. On paper, a gun that uses a 5-pound spool sounds very efficient. You’d never need to change that thing out! But it’s important to remember that the spool is mounted directly on the gun, meaning you’ll be holding the entire thing all day long. It might not sound like that much weight, but compared to a MIG gun, a spool gun can start to feel pretty heavy after an hour or so. Because of this, we’d recommend sticking with a 1-pound spool unless you’re working on your biceps.

Once you’ve got a compatible spool gun, the only final thing to remember is that your settings might be different with a spool gun compared to a MIG gun. You’ll also need to calibrate your new spool gun, a process that can vary depending on the machine. In theory, all the settings should be the same, but that’s often not the case with parameters like wire speed. Make sure you do a few test lines first.

Your best option for buying a spool gun is online. Welding Supplies from IOC has a great selection of spool guns for all the top brands and fast shipping. Check out their entire selection here.