Signs Your MIG Gun Is Overheating — and How to Prevent It
An overheated MIG gun can result in downtime, wasted consumables and lower productivity — costing a company more time and money than necessary.
Gun overheating can be a symptom of numerous problems, and it can result in catastrophic failure if ignored. Being aware of the common signs and causes of MIG gun overheating can help prevent or quickly remedy the problem.
Always know the gun’s amperage and duty cycle rating and the parameters of the welding application. This information tells you how long a specific gun can be used and under what conditions.
Watch for the signs
Gun manufacturers test and rate their products to prevent overheating. A gun’s assigned rating reflects the temperatures above which the handle or cable becomes uncomfortably warm — not the point at which the gun risks damage or failure. In addition, specific duty cycles are tested for each gun, such as 100 percent duty cycle with 100 percent carbon dioxide (CO2) or a 60 percent duty cycle with a mixed shielding gas (CO2/Argon). Most manufacturers list the amperage-to-duty-cycle ratios in product literature, so research a gun’s rating before purchasing.
Signs that may indicate the MIG gun is overheating.
Common causes of overheating
Exceeding duty cycle
Operating the gun for too long is a main cause of overheating. Know the duty cycle and amperage ratings of the gun, and don’t exceed the duty cycle when possible. When a gun is consistently overheating, you likely need a larger capacity gun for the application. This allows for welding at higher amperages for longer. However, in welding applications that require short bursts of welding — such as thirty 1-inch welds — a larger amperage gun is often not needed and a lighter, more flexible gun may be the right choice. Be aware that shielding gas also plays a role in gun temperature. Mixed gases typically run hotter, while 100 percent CO2 provides more latent cooling to help keep the welding process cooler.
Not enough stickout
Improper stickout or recess of consumables can be another cause of gun overheating. Adjust stickout to make it slightly longer or change the consumables. A longer stickout — combined with a higher wire feed speed and voltage — helps keep front-end consumables out of the weld puddle and running cooler. Also, when the application calls for a higher duty cycle or amperage and the gun has a flush nozzle, pull the tip back 1/8 to 1/4 inch to better protect it from the heat. Using a slightly longer gun neck can also help absorb more heat from the weld puddle, reducing overheating opportunities.
Improper or faulty ground
A faulty ground or a ground that is too far from the point of the weld can also cause front-end consumables to overheat and wear prematurely. To help combat this problem, position the ground as close to the weld puddle as possible and use as large of a cable as possible to provide a good connection.
Preventing gun overheating
Knowing the warning signs of gun overheating can help prevent the costly downtime. In applications where the gun is frequently overheating, it may be necessary to switch to heavier-duty consumables or use a larger capacity gun.
Implementing some best practices can also help reduce the occurrence of MIG gun overheating — to help you maximize productivity and savings.