Weld spatter commonly happens on any arc welding. And any welder, even the hobbyists who do GMAW or gas metal arc welding knows spatters are produced because some things made it happen. But what is GMAW that makes it vulnerable to spatter? GMAW is a form of arc welding that uses gas in shielding the weld pool from air contamination. Arc is produced when the positively charged electrode gets in contact with the work metal that is negatively charged. This spark ionizes the gas and burns it up and the plasma arc is produced.
GMAW can be in two forms – Metal Active Gas (MAG) welding that requires pure carbon dioxide (CO2) and the popular Metal Inert Gas (MIG) welding that needs the mixture of inert gas into carbon dioxide.
So what is a spatter in welding? Spatters are droplets of molten electrodes that flies out during the welding process. You can see them near or around the welding spot in various forms but are usually rounded. Spatters are common among GMAW applications because something has caused the melting electrodes to jump out either from the welding pool or from the melting electrode. Although the smallest spatters are easy to remove, they also become a nuisance when they get too many and large.
What Causes Spatter
The most common cause of spatter in welding can be due to high wire speed while the amperage is low. Without sufficient current to melt the electrode, this causes some of the molten metals to jump in many directions due to the inconsistent melting of the electrode.
Another common cause of spatter in welding is the mismatching of voltage and the amperage. If the welding voltage is too low or if the amperage is too high so that they don’t complement the size of the wire and the gas mixture, this can cause the arc to get cold and the result will be the disturbance on the weld pool that will cause the spatter.
Thermal arc blow. The arc resistance on the work metal becomes inconsistent due to the dirty metal surface and improper travel speed of the torch.
By globular transfer mode. Big droplets of molten electrode that drop into the welding pool can cause splashing. This can occur when pure CO2 is used on carbon steel and welding is done on a vertical or overhead position.
Other Weld Spatter Causes That Can
Magnetic arc blow. This is caused by too much magnetism on the metal which the welder is working on. Because the earth clamp is farther away from the work metal and the metal is insufficiently charged negatively, the arc wanders and the welding filler is deflected which also deflects some of the melted metal. The quick solution to this is to ensure that the ground clamp is always near or biting the workpiece.
Wrong wire size or wire is of poor quality. Always read the user’s guide inside the MIG’s door panel for the wire size, right gas mixture and travel speed. Buy only wires that are tested and branded.
Wrong gas mixtures. Pure CO2 will normally produce spatter in welding but the combination of the wrong amount of inert gas to CO2 may also cause spatters. Experts suggest using 90% argon and 10% CO2 for better weld penetration if you intend to eliminate weld spatter using gas mixture.
Dirty, painted or oily welding surface can cause the arc to jump while the melted electrode will not stick solidly on the metal. Clean out the metal surfaces as the electrode needs to get in contact with the metal to produce a constant spark.
Improper wire length. The ideal length of the wire protruding from the nozzle is about 3/8-inch. Too long can cause erratic spark while too short can also make you dip your electrode into the weld pool and can make the melted electrode fly.
Moisture in the surrounding air. The contamination of the weld pool from the atmosphere along with the strong flow of air can cause weld spatter. If working outdoors, put up a tent around you or use flux-cored wire that is not affected by draft and not requiring shielding gas.
How Weld Spatter Can
Those hardened metals may stick not only on your welding table but also into your tools including the nozzle of your MIG torch. Such an event can block the flow of gas into your torch which can ultimately affect the weld or damage your torch’ consumables. Also, with lots of spatter, you may need tools to eliminate them like metal picks and hammers or even grinders especially if there is also some formation of weld splatter.
Spatters can burn through your clothes and burn your skin. Unlike the sparks during plasma cutting which are just small pieces of burning metals that burn while on the air and will not cause damage on contact, spatters don’t change its physical component but only solidifies once it cools off. So anywhere they land that is made of organic material, they can burn it.
It creates a dirty welding environment. You need to clean out your post-welding work especially if there’s a lot of spatters which can be time-consuming and can reduce productivity.
Another potential problem other than the spatter in welding is weld splatter. Most often, people confuse weld spatter to “weld splatter” because both mean scatter in particles. But in welding, spatters are small rounded metal particles like droplets while splatters are larger and have shapes like blobs. But what causes welding splatters?
If spatters happen in using MIG welders, the same with the splatters. But if spatters are molten electrode particles that fly out during welding, splatters are molten electrodes or fillers that splashed and formed on the welding surfaces. Splatters stay on the surface like blobs but also hardens along with the fillers. The things you may need to eliminate it would be a chipping hammer, cold chisel, or flap discs for the angle grinder.
Spatters and splatters are both bothersome occurrences in MIG welding. But weld splatters are not very common unless your wire becomes too long and the arc is positioned too high from the welding spot. These enable the filler to burn cold and form metal buildup on top of the welding and can even flow around the work metal.
Most weld splatters are not attached to the hardened filler so these can be easily removed using chipping tools. If spatters can be caused by too many factors including low amperage/voltage that causes short arc, weld splatters can be caused by a lengthy wire and high arc.
How To Prevent Weld Problems?
If you read back what we have mentioned about the causes of spatter in welding, you may now realize some solutions to enhance your welding and eliminate spatters and weld splatter. But we still encourage you to do the following preventive solutions for a cleaner welding job.
Avoid using poor quality equipment which can lead to irregular welding processes. If you think your budget is limited to buying quality welding equipment, try searching the web. You may be surprised that there are a lot of reliable MIG welders out there that can even match some of the expensive units. To know the machine’s capacity, read users’ comments, reviews and forums from different websites.
Always check your settings based on the type of metal you need to weld. For example, you want to weld stainless steel, then you have to determine the appropriate wire speed and amperage setting required for the stainless steel wire. If you switch to high amperage with slow wire speed or the opposite, this can cause weld spatter as well as weld splatter. So you need to balance both the wire speed and the amperage until you see that there’s no more spatter in welding.
Avoid electric stick out. This means you should keep a proper distance between your torch contact tip and the workpiece at about 3/4-inch. With the end of the nozzle very near the workpiece, while the unmelted wire electrode gets to dip into the weld pool, this can lead to the restriction of shielding gas and produce spatter in welding that can result in porous welding.
Learn the right mixture of gas for your metals. Not all MIG gas types can be suitable for all metal types. For example, if you use C25 on aluminum, this will not work and may cause burn and weld spatter. The right gas would be pure argon. You can refer to your machine’s manual or from the inside panel of your machine for the right mixture of gas per metal type.
How To Eliminate Weld
Always have a ready angle grinder, hammer, flat rod and flap discs in removing spatters. For weld spatter, place the chisel point on the base of the spatter and tap the end of the chisel with a hammer lightly. Put more force on the tap if the spatter doesn’t move. If some stick out metals remain on the scene, use the grinder as a last resort.
With weld splatter, do the same tasks as with the spatter using a chisel and a hammer. Then the grinder as the last option and also in refining the weld surface. Make sure you wear safety glasses in removing both spatters and splatters.
For medium-sized splatter, better attach a flap disc on the angle grinder and skim the splattered surface in constant motion.
Expert welders know that dealing with spatter in welding and weld splatter can be rigorous and counter-productive especially when they have to deal with large pieces of metals. So most of them advise using anti-spatter spray products before starting to weld. These products cannot remove spatters or splatters but can provide a protective shield on the metal area where you will lay down your project.
Setting Your Welder to Prevent Splatter
Set the voltage according to the metal you want to weld and also the type and size of the wire based on the welder’s chart found in your machine.
Set the wire speed, voltage, and gas flow in small adjustments first and fine-tune until you get a smooth flow of arc.
Check the ground or work clamp if there’s a good bite on the welding table near the workpiece. The ground clamp should be close to your weld. If there’s a weak connection of the ground to the work metal, the welding arc can fluctuate. Choose a copper-cast clamp for a more secure flow of the ground current.
Check also the wire feed tension. Loose drive rollers can make erratic feeding of the wire. Also, check if you are using the correct drive roller according to the size of your wire. Erratic wire feeding can mess up your welds with weld spatter and weld splatter.
Check if the gas is going out of the torch’ nozzle. You can disengage the wire feed tensioner and then pull the trigger to check. You must hear the flow of gas that must come out from the nozzle.
Finally, check your consumables. Oversized contact tips or worn nozzles could also produce spatter on your welding. An oversize contact tip opening could lose some contacts on the current which can cause splatter and spatter.
Weld spatter and weld splatter may be caused by many factors. But as welders, we can always find solutions to address these common welding nuisances. This is why we have provided you info on what can cause them, ways to diagnose the cause and some solutions that can help you get rid of these including some preventable tips for spatter control.
Moreover, one of the best methods we can advise you to avoid getting bothered by spatters and splatters is using a welding anti-spatter spray. Such products can protect the metal surface from any flying molten metal and prevent them from sticking in. So this is some kind of preventive treatment rather than the cure because once the metal droplets and splatter get in contact with the metal without the anti-spatter material, there is no other way but to remove them manually.
You can also spray this product right on the nozzle of your torch since some spatters may also get into the nozzle opening and block it thereby affecting the weld. Look for a silicone-free product to avoid contamination of your weld.