What Causes Weld Spatter and How to Avoid It

From this article, we'll explain what causes weld spatter, including faults in metal, technique and filler, and give advice on how to avoid it
Christopher McDonagh
Christopher McDonagh
Research Writer
Chris is a teacher of Literature at a school in New Berlin, Wisconsin. He is also our favorite irreplaceable freelance writer who can turn such a boring topic into something read more
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Thomas Garcia
Thomas Garcia
Expert Consultant
Thomas is a professional welder who gained his certification several decades ago and learned all the nuances of this job since then. When not at work, Thomas loves fishing i read more
Last updated: August 09, 2023
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Every welder wants to do a project that reflects well on them but that could be put in jeopardy if they found tiny metal balls melted around their weld after they had put the finishing touches to the workpiece. A phenomenon called spatter is responsible for the tiny metals which deteriorate product quality according to a 2017 study Trusted Source SAGE Journals: Your gateway to world-class journal research Subscription and open access journals from SAGE Publishing, the world’s leading independent academic publisher. journals.sagepub.com

Besides, the common question on most welders’ lips is; what causes weld spatter? That’s a good question because knowing the cause of the problem gives you the chance to solve it or minimize it because frankly, you can’t avoid spatter completely. Some of the causes include the filler wire, metal, settings, or techniques. In this article, we’ll provide you solutions to each of the common causes of weld spatter. Apart from that, we’ll discuss other moves that can help you avoid weld spatter in the future. 

What is weld spatter

What Causes Weld Spatter and How to Avoid It
Small blobs around the weld make the final result look unprofessional

What exactly is a weld spatter? It defines blobs of excess molten metal that are spat from the weld and bond with almost everything—including your body and workpiece—because they’re in a liquefied form. Weld spatter is known for leaving a nasty mess on projects. Sometimes, it can even burn through your overalls onto your skin. 

Without any doubt, weld spatter poses a significant concern to welders and the best decision any welder can take is to learn about the problem and how to fix it. 

Filler caused weld spatter

A major cause of weld spatter is the filler wire. If it lacks good quality, then it will be a problem. Below, we’ll explain how it can be a problem: 


Sometimes, the quality of the filler is not the problem. Rather, the problem is caused by contamination of the filler. If left uncovered, filler wires can be contaminated with dirt, dust, and oil, causing rust, which is not good for the weld.


The best way to keep your filler wires/rods uncontaminated is to keep them covered whenever they aren’t in use. Although stainless steel filler rods hardly rust, they’re not entirely safe because steel dust can cause them to rust. So, you should keep them away when grinding steel. 

Furthermore, MIG—Metal Inert Gas—welding spools and SMAW—Shielded Metal Arc Welding—rods should also be kept covered to prevent contamination of the weld which causes spatter. 

Low-grade filler

Buying a low-grade filler may feel like a financially smart move but the compromise is not always worth it because most often than not, the result is extra spatter. 


You can’t afford to buy a poor-quality filler because that puts your project at risk. Therefore, you should carefully research the filler for quality before you buy it. While we understand the need to buy at the best price possible, that shouldn’t lead you to sacrifice quality and buy the wrong product. With a high-quality filler, you can get the least spatter. 

What Causes Weld Spatter and How to Avoid It
Aquire big number of welding fillers to always have at least dozen at call

Metal caused weld spatter

Besides the consumables, the material you weld can also cause weld spatter. For instance, if the metal is not good enough, spatter may cause you problems.


A dirty metal can cause weld spatter. The dirt may be a result of grease, a bit of dust, or oil. Regardless of the source of the dirt, it won’t merge well with the weld, thus causing spatter troubles. 


The solution here is simple; clean the metal before you weld! Don’t just pick up metal and start welding, ensure that it is free of dirt to protect yourself against the nightmare called weld spatter. 


Sometimes, the quality of the material doesn’t necessarily contribute to spatter. Instead, the coat of the metal does, making it impure to be welded. And an impure metal will cause spatter. Essentially, a pure material goes a long way to have a clean weld that produces less spatter. 


What Causes Weld Spatter and How to Avoid It
There are several methods to remove metal coating, power grinding being the most effective

Before you weld, remove the coat around where you’re going to weld, leaving you with a pure surface. Welding a pure surface inadvertently means less spatter. 


If metal is not dirty and it doesn’t have a bad coat, then the composition may be the problem. Interestingly, some metals are not made for welding. Even some that are designed for welding are made with cheap additives. The result of such metals is excessive spatter. 


You need to pay very good attention to the composition of the metal you’re using. Ensure that it is designed for welding. If it is, ensure that it’s not cheaply made. Otherwise, don’t go for it; go for a new metal instead. However, if you’re stuck with such “unweldable” materials, follow our tips on how to avoid spatter to save yourself from the impending trouble. 

Setting and technique caused weld spatter

There are times that the spatter problem comes from neither the filler nor the metal. Rather, the problem arises from the wrong settings and techniques. Below, we’ll discuss how SMAW and MIG settings and techniques can cause weld spatter: 


Weld spatter can arise as a result of poor heat setting. If your heat is not enough for the metal thickness and the sized rods, your weld will lack a smooth consistency, thus leading to excessive spatter. In terms of technique, pulling creates more spatter than pushing. 


The best way to be sure that your SMAW welder settings are good enough is to practice on some scrap metal. Then, adjust the settings until you’re satisfied that the heat is good and it won’t cause a spatter. You can opt for the Forney 220 ST PRO Welder because of its easy settings. Plus, it can do both stick (SMAW) welding and TIG welding. 

Also, be consistent with your welding speed for a clean weld. Additionally, pushing is a better technique but don’t limit yourself to only one technique. Most importantly, use the right technique for your weld’s requirement.


When using MIG, you want to know that the heat setting is great. If the welding is not hot enough, the weld won’t be smooth and will cause a spatter. Also, firing at the metal at the wrong angle can cause a spatter. 


Ensure that you get the SMAW settings right by practicing on some scrap metal before going ahead with your project. Also, ensure that you fire at the metal at the right angle. Specifically, don’t fire at any angle that’s more than 15°. Otherwise, you’ll get spatter all over your project. 

How to avoid weld spatter

Besides the causes and solutions we explained above, we’ll explain how to avoid weld spatter altogether. 

Welding tape

Welding tape is typically made from aluminum. Apply it to areas you want to avoid spatter. It is quite effective at keeping out spatter from all treated areas although it’s pricey. While other tapes may go for lower prices, we recommend aluminum tape because those alternative tapes can melt or burn from the spatter. 

Gas change

Changing your welding gas may be the best way to avoid spatter or stop it because the type you use contributes to how clean your weld is and consequently, the amount of spatter the weld creates. While there are several gases you can deploy to protect your MIG welding, for example, pure argon and pure Co2 are the best to use although the former produces less spatter than the latter. You can even mix both gases but argon will form a very significant part of it. 


Another tool that can help you avoid weld spatter is a grinder. It will grind the spatter to a clean finish in a short time. Also, the grinder does a quick job. 


Anti-spatter is typically an oil-based spray. When applied over a welding area, this spray prevents spatter from bonding with your workpiece. It leaves loose balls that can be easily be brushed off or chipped away but some spatter may remain and melt into your project. 

You can’t find a high-quality spatter? You should consider the CANTESCO AS-16-A Anti-Spatter because it’s been touted as a reliable product by hundreds of users. The product prevents spatter buildup on welding projects and it’s not flammable.

Spatter hammer

What Causes Weld Spatter and How to Avoid It
Spatter hammer has a thought-through construction with impact-absorbing spring handle

Spatter hammer does exactly what it sounds like. It usually sports a cold chisel head that can easily chip away spatter from your workpiece. It’s easy to use and does a near-perfect job. 

Remember to weld in only an unconfined space, clear away flammable materials before starting a welding task, observe other safety precautions as advised Trusted Source Welding: Safety risks from welding - HSE The main risk from confined space working is the lack of oxygen. You may be working in an identified confined space, but you should also be aware if your workspace could become a confined space as you weld. www.hse.gov.uk by the United Kingdom’s Health and Safety Executive (HSE). 

Final Thoughts

No doubt, spatter is every welder’s nightmare. No welder wants to see it melt into their project. Although it can’t always be avoided, it can be minimized to a great extent, which brings us to what causes weld spatter. By identifying the causes, you easily find a solution to the problem as you can see in this article. 

We advise that you avoid welding a dirty metal or using a contaminated filler wire. This article contains every major cause and solution to weld spatter. You must carefully study this guide to have a great shot at getting rid of your spatter problem for good. Plus, you should strongly consider a high-quality welder among the best welders for aluminum, best TIG welders for aluminum, and the best 120V welders on the market for the best results. 


SAGE Journals: Your gateway to world-class journal research
Subscription and open access journals from SAGE Publishing, the world’s leading independent academic publisher.
Welding: Safety risks from welding - HSE
The main risk from confined space working is the lack of oxygen. You may be working in an identified confined space, but you should also be aware if your workspace could become a confined space as you weld.
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