How do you remove MIG welding spatter?

What is welding spatter?

MIG welding spatter refers to the small droplets of molten metal that is produced during the welding process. Welding spatter is typically caused by the interaction between the welding arc and impurities present on the metal surface. These liquid metal blobs, also referred to as bbs, can stick to your project or worse your skin. 

It’s normal to see spatter around the weld joints, especially for Metal Inert Gas (MIG) welding, so it’s not a serious issue. (Unless it is excessive and your weld program needs adjusting to improve weld quality.)

Why is welding spatter a problem?

Too much spatter balls sticking to workpieces or tooling can lead to the poor quality and appearance of the weld. Sometimes it can even lead to you having to throw out a project because you can’t remove the blobs.

Welding spatter can also increase the time and effort required for post-welding cleanup. The small metal droplets can be difficult to remove, especially if they have solidified and adhered to the surface. This can result in additional labor costs and delays in the production process.

Another problem associated with welding spatter is equipment damage. When spatter lands on welding equipment, such as the welding gun or nozzle, it can cause clogging or blockages. This can lead to poor gas flow, reduced welding performance, and increased downtime for maintenance and repairs.

Welding spatter can pose safety hazards to the welder and those working in the vicinity. The molten metal droplets are extremely hot and can cause burns or eye injuries if they come into contact with unprotected skin or eyes.

Causes and Solutions

Spatter is a nightmare for many welders, especially for begninners and although you can’t avoid it completely, you can try to lessen the amount you produce to keep your workpiece clean and minimize the need for manual post-weld cleaning techniques.

Metal composition and coating

The composition of the base metal being welded plays a significant role in the formation and severity of welding spatter. Different metals have varying physical and chemical properties, which influence their behavior during the welding process. Some metals are more prone to spatter than others. Metals with lower melting points, such as aluminum, tend to produce more spatter compared to metals with higher melting points, like stainless steel. The lower melting point causes the metal to become more fluid, increasing the likelihood of spatter formation.

Another factor is the presence of impurities in the metal. Some low-grade alloys contain a lot of “filler” material that ultimately affect the metal’s weldability. Instead, they create lumps in the weld pool, which causes the molten material to spatter.

Solution

• The metal you are welding should be selected with the right welding properties in mind

• Avoid suspiciously cheap metals. Do research on the quality of the metals you’re planning to use before buying them.

Machine parameters:

Setting parameters are also critical factors in determining the amount of spatter produced during welding. The main machine parameters that affect spatter include:

• Wire feed speed

• Welding current

• Voltage

• Shielding gas flow rate

The correct amperage will be determined by the speed of your wire. If your amperage is too high, it will cause spatter. Oppositely, a voltage that’s too low will also lead to the same result. Your gun’s manual should give you a suggestion on the correct voltage.

Solution:

To troubleshoot, reduce the amperage by slowing down the wire, or increase the voltage – or find a balance between the two. Remember to experiment with different settings and make incremental adjustments until you find the optimal parameters for your specific welding application. By carefully adjusting the machine parameters, you can effectively reduce spatter during the welding process. 

Welding technique

proper technique is essential to keeping spatter at a minimum.

Travel speed: The speed at which the welder moves along the joint, known as the travel speed, can impact spatter. A high travel speed can result in insufficient heat input, leading to poor fusion and increased spatter. Conversely, a slow travel speed can cause excessive heat input, resulting in more spatter.

Travel angle: A steep electrode angle can increase spatter due to the increased heat concentration at the point of contact. A shallower electrode angle can help reduce spatter by distributing the heat more evenly. You should hold the MIG gun at no more than 15 degrees from vertical.

To reduce welding spatter, it is important to use the proper welding technique, check machine parameters. 

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.

Solution:

make sure that your consumables are properly sized — wire to the liner, to contact, tip, to the nozzle. Using the correct quality parts can go a long way toward preventing excess spatter and many other issues.