Blogs By Cyclotron
Top 10 causes of weld spatter & how to reduce them
What is a Weld Spatter?
While Welding, we observe sparks flying out of the weld zone, spread in all directions, across the weld area. These sparks are the molten metal (or non-meta)l, coming out of the weld pool and is well known as a Spatter in welding terms.
The spatter, as it is hot molten metal, clings to the surface, wherever it falls on. Spatter is a welding defect and poses the biggest challenge to the skill of the welders.
It not only increases the work of the welder in cleaning the workspace but also harms him when falls on his clothing if not proper protection equipment is worn.
The minute hot sparkles stick splashing out of the weld pool, sticks to the workpiece and tool, depreciating their life and performance, falls on the surface of the base metal, resulting in poor surface finish and results in loss of metal due to spatter.
The Causes of Weld Spatter
1. Metal composition
Not all materials are suitable for welding. Some metals contain components with poor weldability. Few manufacturers use cheaper additives to reduce the cost. They may contain contaminants and impurities that cause excessive spatter.
The quality of filler to be used is important. Low grade and cheap coatings seriously affect the weld quality and produce excess spatter. Quality comes with a cost. Some money has to be spent to improve quality and minimize spatter.
Using the right material and specific coatings on the metal before you weld, minimum spatter can be obtained. These coatings include galvanised coating, coatings of zinc, rubber, etc to cover the surface.
The area to be welded should be grinded slightly to remove the coating so that fresh metal could be welded without contamination and spatter can be minimised.
2. Presence of impurities
The cleaner the weld is, the less spatter will be formed.Dirt is an important contributor to spatter. If the base metal is not cleaned properly or contains oil, grease, scales, etc it makes the weld arc spit and splashes spatter, out of the weld zone. Clean the base metal and the area to be welded before performing the fabrication operation.
3. Poor handling of Welding equipment
Welding equipment should never be left free and uncovered. There are high chances of contamination of the fresh metal. The metal may be exposed to Oil, dust, and rust leading to corrosion that causes excessive spatter. After use, the welding components should be cleaned and wrapped up for safe and better handling.
4. Welding parameters
Weld settings and machine settings play a crucial role in producing spatter. If the amperage is too high or voltage is too low, weld spatter occurs. Also, if the distance between the contact tip of the electrode to the workpiece is more, weld spattering occurs due to the lack of penetration and porosity.
Accurate machine settings are required for smooth welding and stable arc which minimizes weld spatter to a great extent. The accurate settings come with experience. However, setting charts and programs can be used as a reference, as some minor adjustments have to be made according to real-life conditions.
Amperage, voltage, and speed combination should be accurate for fine-tuning and smooth welding with minimum or no spatter.
5. Wire feed problems
The dirty or rusty spool of wire feeds erratically and produces excess spatter. Too fast wire feed disturbs the arc and causes excessive weld spatter. Non-uniform wire feeding fluctuates the amperage and causes spatter.
6. Roller setting and handling:
An appropriate drive roller has to be installed according to the wire size. If the roller size is not exact, the wire feed will not be in tension, it will be loose and will slip over the roller due to which current fluctuations occur and result in a lot of spatter.
7. Welding gas
The gas flow rate for shielding gas is one of the parameters that decide spatter. The CO2 gas in MIG welding acts as a shielding gas that not only protects your weld but also helps to stabilize the arc. The improper flow of gas from the cylinder interrupts the continuity of the shielding gas over the weld area. The lack of shielding gas disturbs the stable arc and produces spatter.
C02 and Argon gases work best as shielding gases. Different combinations can be used for different types of welding.
8. Poor earth clamp connection
If the earth clamp connection is loose, it makes the arc fluctuate and causes splatter. Check the clamp and machine for loose connections. Attach your clamp closer to your weld area for stronger connections.
9. Improper contact tips:
Oversized, loose, or worn-out contact tips of a weld nozzle cannot carry the current properly. As a result, the arc gets unstable and leads to spatter. With an oversized contact tip opening, the wire electrode can lose contact with the tip and cause spatter
10.Incorrect Torch angle:
Usually, the torch angle should be 5-15 degrees from vertical, which helps the shielding gas to protect the weld area efficiently. It is easier to deviate from the angle if we try to view the weld puddle. Too much gun angle pushes the gas to one side and leaves the other side unprotected which results in weld spatter and weld porosity ultimately.
Steep angles and some welding techniques cause spatter if you drag too fast.
Conclusion
Some anti-spatter sprays are advertised to reduce spatter. But the Anti-spatter gel or spray doesn’t reduce spatter. A light coating of anti-spatter spray on the weld nozzle can prevent the spatter from sticking, making it easier to clean.
Most of the causes of weld spatter and solutions to eliminate it have been addressed in this article. In addition to the above, skill and expertise of the welder is also a key factor in contributing to the spatter.