Contact tips are meant to fail. They’re one of the most used (and abused) consumables, and it’s important to replace yours on a regular schedule. But ask any welder their frustrations about the job, and premature contact tip failure is likely to be near the top of the list. It’s a common problem that can lead to degraded weld quality, downtime and extra costs that take a heavy toll on efficiency and productivity.
Failing contact tips are usually the result of problems such as wear, burnback or poor-quality equipment. While all of these issues are fixable with a bit of troubleshooting, it’s always a better bet to stop them from happening in the first place.
Contact Tip Wear
Premature wear on a contact tip usually happens when the wire generates too much friction as it feeds through the bore. Its likely causes are an incorrectly sized contact tip, the wrong wire-to-nozzle ratio or excessive heat. Switching your consumables with right-sized parts is relatively simple and should result in a long-term fix. But if excessive heat is causing your contact tip to melt, you may need to upgrade to a stronger tip, or depending on the work, a heavy-duty setup.
Other factors that contribute to wear include tip design and quality. For the most part, contact tips are made from copper due to its availability and conductivity. As a result, contact tips without a smooth id bore are poorly designed or made from low-quality copper also have a tendency to wear out too early. Always choose high-quality copper contact tips, or for higher-amperage jobs, chrome zirconium.
Contact Tip Burnback
Burnback happens when a weld forms at the top of the arc and “burns back” into the contact tip. It causes a lot of downtime and may melt the tip, but it didn’t necessarily start there. Burnback can initiate anywhere along the gun, which makes troubleshooting more complicated.
Your first course of action might be to just junk your tip and get a new one, but that eventually leads to higher costs and more downtime. While it may take longer at the outset, assessing the entire gun to find the root issue will save time and money in the long run.
RELATED: Five Causes of Contact Tip Burnback
A loose contact tip can cause the consumables to heat up faster and anneal to the nozzle which causes premature wear.
Make sure that your consumables are kept tight and that no threads on the contact tip are damaged to avoid having to swap out multiple parts on the front end of your torch.
First and foremost, use a good-quality contact tip. The phrase “you get what you pay for” certainly applies here, and if you find yourself needing to replace your contact tip inventory too often, it may be time for an upgrade. Choose a tip that has a smooth id bore, the right size for the job, and doesn’t have a large tolerance, or variation in movement when the wire exits the nozzle.
Second, remember that although the contact tip is only one piece of the welding gun, it doesn’t operate in a vacuum. Follow a routine maintenance schedule for the entire setup to prevent issues that can lead to contact tip problems. Consult your manufacturer’s instructions if you are uncertain of anything, and keep everything -- including your base metal -- clean.
Contact tip failure is bound to happen at some point, but diligence and regular care can help ensure that yours lasts as long as possible.
For even more tips and tricks, download our free MIG Troubleshooting Guide.