Common MIG Welding Mistakes and How to Avoid Them
MIG welding also known as inert gas welding is a very popular welding method that produces high-quality welds. It is very easy to learn and produces fewer mistakes. Because of its efficiency, it is used in various industries like automation, construction and manufacturing.
It is different from traditional welding methods because in this a continuous fed wire is used. Shielding gas is also used in inert gas welding to produce clean and smooth welds. But if we don’t perform this method properly it can result in mistakes and defects in welds.
Welders make many mistakes while doing MIG welding. For example incorrect machine settings, poor shielding gas coverage, choosing the wrong wire type and many more. Shielding gas also plays a very important role in determining the quality of the welds.
For example, if there is not enough shielding gas, the weld can become weak and brittle. If you use the wrong technique it can also result in expensive repairs, wasting materials and accidents. But the good news is anyone can master MIG welding by improving their skills and learning from their mistakes.
In this article, we will discuss some of the common mistakes that welders make and some tips on how to avoid them. By following all the correct techniques so can definitely get high-quality welds.
1. Incorrect machine settings
Incorrect machine settings are one of the most common mistakes in MIG welding. If the machine settings are not set correctly, it can cause many defects. For example, it can result in weak welds, the welds having too much splatter or burnout throughout the metals. We have to adjust three main settings: voltage, wire feed speed and amperage to get the desired results.
Setting the voltage at the correct level plays a major role in determining the quality of the weld. Excessive spatter, burn through or unstable arc can happen if the voltage is set too high.
Due to this, the weld will not be held properly. If the voltage is very low the weld will not penetrate the metal enough. This will cause weak welds to have poor fusion. Wire feed speed also plays a very crucial role.
Uneven beads can happen if the speed is too high. The arc can become unstable if the speed is too low. This makes it difficult to control the weld.
How to avoid this mistake:
Before starting the welding, have a complete knowledge of the manufacturer’s settings chart for voltage, wire speed and gas flow. Perform a test weld on a patch of metal. Always adjust the settings based on the metal thickness and welding position.
2. Poor shielding gas coverage
Poor shielding gas coverage protects the weld from contamination by oxygen, nitrogen and moisture in the air. Tiny holes in the weld can develop if there is no proper shielding gas coverage. Due to this the weld can crack or fail under pressure. If there is a low gas flow rate, it will lead to defects in the weld. Due to this wind or air drafts blow away the gas and leave the welds exposed.
On the other hand, if there is a damaged gas nozzle it will also result in a low gas flow rate. Sometimes welders also forget to turn off the gas supply or use the wrong shielding gas.
How to avoid this mistake:
To get the best results, use the correct gas mixture. For example, in the case of mild steel use 75% Argon and 25%CO2. In order to ensure proper coverage set the gas flow rate between 20-25 cubic feet per hour. Make sure that the nozzle is neat and clean.
Check for gas leaks in the hoses. To get strong welds, avoid working in a windy condition because it can blow the gas away. If it’s the only option left for you then use a welding screen to block the welds.
3. Incorrect electrode sticks out
It means how much the welding wire sticks out of the welding tip when it has not touched the metal. Weak penetration or reduced splatter can result if the stick out is too long. If the stick out is short it can result in heat build-up.
How to avoid this mistake:
Try to maintain the electrode stick out of about 3/8 to 1/2 inch. Based on the welding conditions and wire thickness, adjust the stick out. To get stable welds keep the welding tip clean.
4. Wrong welding technique
Common welding mistakes like holding the torch at the wrong angle or moving your hand too fast or too slow can result in defective welds.
How to avoid this mistake:
For better control hold the torch at a 10-15 degree angle. Try to keep a steady travel speed and practice on scrap metal before starting the work.
5. Poor metal preparation
If the metal is not cleaned properly and has dust, oil, debris and paint on it, it can produce weaker welds. These impurities can contaminate the weld and can result in weak joints, porosity and lack of fusion.
How to avoid this mistake:
To remove the rust, paint and dirt use a brush or sandpaper. Use acetone or a degreaser to clean the metal surface. Make sure that the metal is free from moisture as water can cause hydrogen production into the weld.
6. Using the wrong wire type
There are different wires available for different metals. Using the wrong wire type can result in ineffective results. If you use flux cored wire instead of solid wire it can cause poor penetration or excessive splatter.
How to avoid this mistake:
The correct wire type according to the metal type will lead to your desired result, for example.
- ER70S-6 for mild steel you should use this wire type.
- ER308L for stainless steel you should use this wire type.
- 4043 or 5356 for aluminium you should use this wire type.
3. Incorrect electrode sticks out
It means how much the welding wire sticks out of the welding tip when it has not touched the metal. Weak penetration or reduced splatter can result if the stick out is too long. If the stick out is short it can result in heat build-up.
How to avoid this mistake:
Try to maintain the electrode stick out of about 3/8 to 1/2 inch. Based on the welding conditions and wire thickness, adjust the stick out. To get stable welds keep the welding tip clean.
7. Lack of proper safety measures
If you don’t take proper precautionary measures it can result in severe skin damage, burns and long-term health risks.
How to avoid this mistake:
Always wear a proper welding helmet with an auto-darkening lens. Wear heat-resistant gloves, and a welding jacket and try to work in a well-ventilated area.
Conclusion
MIG welding can only produce your required results if you avoid the above-mentioned mistakes. You should adjust the machine settings properly, ensure proper gas coverage and use the right welding technique. It is very easy to learn but small mistakes can sacrifice the quality of the weld. If you use the correct approach then you can master MIG welding.
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