Ask any welder what causes spatter when MIG welding, and the answer will be … MIG welding. MIG setups use electrode wire that bonds with the metal to form the weld, and spatter is the excess molten wire that bonds with everything else. Too much spatter can lead to downtime for cleanup and wasted materials. And, if it bonds with your workpiece it can be especially painful.
In MIG welding, there’s no “how to avoid spatter.” But if you’re having trouble with excess spatter that’s ruining your work, this checklist can help you reduce it.
1. Incorrect Parameters
First, inspect your machine parameters to make sure they’re running at the right settings for your application.
Amperage & Voltage: The correct amperage will be determined by the speed of your wire. If your amperage is too high, it will cause spatter. Oppositely, voltage that’s too low will also lead to the same result. To troubleshoot, reduce the amperage by slowing down the wire, or increase the voltage – or find a balance between the two. (Alternate between fine-tuning your settings and running test welds until you notice less spatter.)
Polarity: Be sure it’s correct. If you’ve recently switched from solid wire to flux-core, this one is easy to overlook.
Stick-out: Too much stick-out can dig into the weld and cause spatter (along with a host of other issues). Too little, and you may develop an erratic arc. For MIG welding, we recommend using the shortest allowable wire stick-out for the application.
2. Erratic Arc
Incorrect wire stick-out isn’t the only cause of erratic arc. It can also stem from incorrect drive-roll tension, a bad ground, a dirty liner, the wrong-sized contact tip… the list is long. If your arc starts to sputter or crackle, you’ll want to troubleshoot right away to avoid spatter buildup.
RELATED: Fixing an Erratic Arc
3. User Error
Is dragging or pushing the proper technique for MIG welding? It’s a hot debate, and mostly a personal preference. But whichever way works best for you, proper technique is essential to keeping spatter at a minimum. Optimally, you should hold the MIG gun at no more than 15 degrees from vertical. A deviation away from this can cause the shielding gas to cover the weld unevenly.
Dirty surfaces anywhere from the workpiece to the gun liner can lead to excess spatter. Check your wire and liner for rust or dirt, and your workpiece for oil, paint, grease or other contaminants. It’s better in the long run to prep your welding surfaces well before you begin so that you can avoid do-overs and having to scrape off spatter later.
RELATED: Why Durable Equipment Matters
5. Low-Quality or Incorrect Consumables
Quality consumables aren’t necessarily the most expensive, but they’re reputable, long-lasting, consistent, and most importantly the right quality for your specific application. Low-quality wire can vary in diameter as it feeds through the gun at different wire speeds, a less-than-optimal contact tip or liner can clog more quickly. And, as always, make sure that your consumables are properly sized — wire to liner, to contact, tip, to nozzle. Using the correct quality parts can go a long way toward not only preventing excess spatter, but many other issues.
For even more tips and tricks, download our free MIG Troubleshooting Guide.