What Is Welding Spatter And How To Reduce It?

What is Welding Spatter?

Weld spatter is molten metal or non-metallic material droplets dispersed or splashed during the welding operation. These tiny bits of molten material may fly off and fall on the workbench or floor, while others could land or stick to the base material or any piece of metallic material near the base material. These weld scraps are easily identified because when they solidify, they are round, a small ball shape.

Weld spatter will likely be most common for gas metal arc welding (GMAW), and when they are in surplus, when the weld spatters are recycled in a furnace, weld spatters will produce solid forms.

The type of material that you welded is a significant measure of how much spatter was produced. Different types of materials affect how weld spatters are produced; the type of metal, the type of it coating and how clean it is are primary factors.

For many welders, spatter is a headache and even though it can’t be avoided entirely, it can be reduced tremendously. As you obtain knowledge of each source, look to the solutions to minimize the effect for an excellent welding experience.

What Are the Causes of Welding Spatter and How Do You Reduce It?

Weld spatter is typically caused as a result of the disturbance of the weld pool. These particles are a distraction to engineering design as they alter the state of the base material surface when they stick.

They can also pose injuries in the workshop and should seriously be viewed by the welder when following safety precautions. Weld spatter may pose a serious hazard with regard to oil based industries. Very Normal contributors to weld spatter include:

• Long welding arc
• Short welding arc
• Cleanliness of the base material surface
• Selection of gas welding (CO2 welding yields more)
• Welding at the wrong angle
• An imbalance between voltage and amperage
• Incorrect wire feed speed

The marks, damages, cracks, or pores left on the surface of the base material can instigate corrosion.

1. Metal Composition

There exist metals that are not intended for welding at all. The different additives in their grades designate strength and no weldability.

There are other metals that are marketed as weldable metals, but they are manufactured in the cheapest possible method and that includes cheap additives to the core mix of manufacturing.

If welding spatters are a concern, stay clear of both types of metals as stated above. As attractive as cheaper alternatives are, the contaminants and non-weldable components included in their production often cause excessive spatter when welded.

To Prevent: These are not the materials to be selecting for welding. To avoid the spatter afforded by these materials, the best possible answer is to find another metal to weld. If there are no other materials to you and you need to weld, follow the “other solutions” section to minimize the impact of spatter on your project.

2. Metal Coating

Although the proper type of material is essential to reducing attribute spatter, sometimes a project requires you to deal with using a type of coat to cover that metal before you can weld it.

This can include any types of galvanized coatings, any type of metal plating such as zinc (Electrogalve), chrome, paint, rubber and anything else that is complete coating of the metal substrate.

In general, the more pure the material being joined, the cleaner the weld will be and less spatter produced.

Some coats such as pre-primed steel purchased off the shelf have been developed with weld contaminants (meaning they don’t contribute to spatter problems) but the overwhelming majority will cause you difficulties if they are not attended to prior to welding.

How to Avoid: Grind off the coat where you are going to weld. The coat will burn away when welded, however grinding it off prior to welding will give you a pure surface to start with that will exhibit less spatter. Make sure you grind at least ¾” around where you are welding. The heat will take anything nearby, burning away any material, and adding to spatter, even if it is not in the proximity of the weld.

3. Dirty Metal

Additionally to metals and coatings on the surface, dirt is another key factor when it comes to spatter. From oil, grease, marker pen lines, and a little dust, none of it is going to incorporate into your weld and will result in spatter.

How to Avoid: Clean it before you weld. Welding is pretty basic and shouldn’t produce too much spatter if you do your prep right, and cleaning is part of that preparation. It doesn’t take much. A quick wipe with a rag before you turn the heat on will help you get a smooth weld and reduce spatter.

4. Weldable Filler

Quality materials yield quality welds, and quality welds have little to no spatter. If you buy quality metal, and you are still using poor quality filler wires or filler rods, then you will still end up dealing with spatter.

Low-Grade Filler

You get what you pay for, and you will see that if you want to reduce spatter, you need to use quality filler metal. Regardless of the welding process, the consumables you use, in this case, filler metal, must be of the appropriate formulation to provide clean welds.

In the case of parent metal, it is typically less expensive for a company to create filler products by inserting materials that are not welding-related. They are still weldable and will provide fill, but typically come with excessive spatter.

How to Avoid: Research the quality of the fillers you want to use before you make the purchase. Do not simply purchase the cheapest filler to save money or buy the most expensive filler to ensure the best filler metal quality. Research the different types, and just make sure that what you purchase is a quality product, so you can generate the least amount of spatter possible.

Contaminated Filler

Welders are notorious for using their consumables and leaving them exposed. Exposed consumables become contaminated with oils, dirt, and dust, or they may begin to develop rust from being inactive. Rust and dirt contaminating the weld and entering the weld pool will result in additional spatter.

How To Avoid: Look after your consumables with a cover when they are not being used. In the case of stainless steel filler rods, this isn’t as important since they do not rust; however, if you take the stainless rods out and do not have a cover, just be sure to wipe them before welding. Steel dust, on the other hand, will rust stainless rods and contaminate a weld. If you are grinding steel, keep the stainless rods away.

Although most MIG spools have sealing covers, the wire should still be in a bag or condition when not being used, unless it is frequently used or used often enough that the spool cover is resealed. Moisture can form on the coil when in an unsealed state, causing rust to form.

SMAW (arc or stick welding) rods have a lower consequence if used improperly; this is because the flux on the rod has an interesting habit of chemically removing everything, including air and other impurities from a weld. Wet or oily rods, however, will create a lot more spatter, so it still worthwhile to keep these in a bag or container.

5. Welder Settings

Purchasing top-grade steel and superb consumables, cleaning everything thoroughly, and getting “all systems go” to weld will not guarantee a good probe if you get significant spatter. Materials are important; if you set an incorrect setting on the welder, you will have the same problem.

MIG Settings

A typical reason for MIG welding spatter is rapid or inconsistent wire feed speed. Spatter occurs when the filler wire enters the weld pool. The solid wire quickly melts under the heat of the steel. As it melts, the filler wire turns into liquid form, which then creates the weld pool.

If the wire is hot enough before it hits the steel, it melts somewhat gently into the puddle with very little spatter. When it is cold enough that it hits the pool before melting and splashes it, spatter flies out with a pop and splutter.

Wire feed will need to be hot enough to melt before hitting the pool at a reasonable pace. If wire is too hot, it will melt too far away from the weld pool which will cause spatter from having a too long distance between the puddle and potentially liquifying wire moving toward it and it can create a sticky nozzle tip from melting too close to it.

There will be excess build up on the end of the wire, which will create an inconsistent feed rate, because the wire will stick and can create even more spatter. Keep in mind that the heat of your weld is determined by adjusting your amperage and/or your volts on your welds.

SMAW Settings

The same concepts apply to SMAW welding. You have to have the heat right for the rod size and metal thickness. If the welding is too cold you won’t get a smooth walking consistency in your weld. It will wander between welding and sticking, leading to excessive spatter, an ugly weld and frustration in general.

At the same time, if it is too hot, you can get a consistent weld, but you must travel quite a bit faster to not burn through the joint or create an undercut. Increased speed leads to an increase in spatter too. You need to maintain a consistent heat, perfect for the plate thickness and rods to get the cleanest welds.

How to avoid:

To confirm that your welder is not playing an active role in the spatter issues you are experiencing, practice on a piece of clean scrap metal to fine tune your MIG and SMAW welder settings until you refine them.

It is always helpful knowing what the recommended setting are for the welder and consumables for your project (usually listed on the welder or packet the consumables came in), but do not trust it if there is still spatter in the weld.

With welding, the variables of reality mean you will often find your own trial and error processes are the best way to go about it, if you are not getting what you want.

6. Welder’s Technique

When I began in the shop, my boss sat the welder up with the perfect settings for the job. I had prepared all my pieces to weld, and they were cleaned perfectly. But as I jumped in with excitement on the project, the weld spat back at me and splattered all the frame.

Theoretically, I had everything perfect, except the technique of how to weld. The lesson I learned was not to lose sight of the basic foundation of welding technique; that yes, you should prepare well, but learning the correct procedures are just as important.

MIG Techniques

If you have a MIG torch at a 20° or more angle where you’re firing into the metal, don’t act surprised when a certain level of spatter flies off.

Getting the angle right not only affects how well your weld penetrates and what the bead looks like, but plays a major role in how much spatter you create too. Travel angle may play a role, but the greater the angle varies from 15° or higher, the more spatter you tend to get.

As stated previously, consistent wire speed reduces spatter. With this, consistent travel speeds along with a steady hand while welding helps produce a clean weld.

The more consistent you can be with the technique your weld requires, the less spatter you will create. Find that angle, speed, and line then stick with it.

You also need to make sure that you’re using the correct technique for the type of weld and material. One example is whether you are pushing or pulling your weld pool.

When your weld draws high and consistent heat input, you should be pulling your weld along (traveling with your torch angled away from your traveling direction).

If your weld requires more heat diffusion rather than a localized heat input, you should be pushing (angled toward your traveling direction). Dry-fitting the wrong technique for the technique your weld requires will produce excess spatter.

SMAW Techniques

There are not as many SMAW techniques with regards to the spatter outcome as in MIG welding, but there are some; pulling for example produces more spatter than pushing.

When you can push, then push but don’t just stick to one technique because it usually produces less spatter. The correct technique for the right weld is also important with SMAW for less spatter.

Make sure that your travel speed is correct, and there is a travel rate that is fast enough to get a clean weld but remember with more travel speed is more spatter. Find a consistent welding rate there and stick to it, and it, along with other factors, should yield the best results.

7. Welding Gas

Gas is another critical factor in spatter issues. Different kinds of gas can greatly impact the cleanliness of your weld, affecting the amount of spatter produced. There are many gases that protect you while MIG welding, the most common and effective being argon and CO₂.

Pure CO₂: Pure CO₂ is less expensive gas to purchase. It protects well and provides decent rooting capability, but it produces substantially more spatter than argon.

Pure Argon: Pure argon is used primarily to MIG weld aluminum (an alloy with minimal problems from spatter) and for TIG welding stainless steel. Argon will not produce quality MIG welds in steel and will, in effect, be the same as pure CO₂ with bad spatter.

Argon and CO₂ Mix: There are many different mixes of argon and CO₂ that are best for different kinds of MIG welding. With some mixes starting with 95% argon, 5% CO₂, 80% argon, 20% CO₂, and various combinations in between. As the steel gets thicker, CO₂ percentage is increased. If you can select the appropriate mix for your thickness, it will create the best possible welding with the least amount of spatter.

How To Clean Spatter?

While these above solutions to reduce spatter from your welding will produce meaningful savings, there will still be spatter most of the time, and no matter what your project is for, it looks bad, and it needs to be taken off.

Removng spatter from welding of steel and stainless steel is a bit easier than from aluminum. These last three solutions will not eliminate spatter; however, they will prevent the spatter from ruining your work or wasting your time.

Anti-spatter

This beneficial product is an oil-based spray you apply to your welding area. It is designed to be welded over and will not affect your weld quality. It stops the spatter from sticking to your metal, which, in turn, leaves mainly loose balls on your project.

Most of it can simply be brushed away or easily chipped away. It is a useful product that you will appreciate but it does leave some things to be desired. You may still have some spatter that melts into your workpiece.

Welding Tape

The tape here is not the normal plastic tape that most think of. This tape is made of aluminum and used anywhere you do not want to have spatter, but is not used directly where you are welding along the lines of anti-spatter spray.

It can be a costly option. But, if you looking at critical parts of your projects like a machined surface, or any part that will be damaged, then this is the best option for you. It may cost money depending where you buy it; it can certainly prevent any spatter from melting in the items you apply it to.

You can use other tapes or other materials if you want something cheaper. But, remember that most materials melt, or burn, or even catch fire since spatter is so hot. Aluminum tape will not let the spatter through.

Spatter Chisel/Hammer

When you’ve implemented all the solutions to create the ideal weld and there are still a few little spots of spatter on your workpiece, a spatter chisel/hammer is your best option.

A spatter hammer has a spring in the handle and a cold chisel head, and with a spatter hammer, you can easily chip away just about everything remaining on your job. The work is quick, easy, and let’s you leave little to no trace of the spatter.

Grinder

The welder’s best friend, with a flap wheel, is another great last resort. While it won’t chip off the residue like a spatter hammer will but it will grind it away to a clean finish!

If you have to do some finishing grinds on the project, it may be quick to forget the spatter hammer and just to give the affected surface a tickle while you are already grinding the other areas!

FAQs