Monday, September 7, 2015

Top 12 Disadvantages of Mig Welding that You Should Know

Mig welding is a widely used arc welding process. Like other processes, it has disadvantages aside from advantages. Know well about its downsides to avoid mistakes with this process and improve weld quality and productivity.

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Despite its paybacks, Mig welding has some drawbacks that you should grasp well.


1. Sensitivity to contaminants

Mig welding process can only deal with low-to-moderate levels of surface contaminants like mill scale, rust, oil, dirt and paint. All those have potential to cause such problems as incomplete fusion, porosity, poor bead appearance, and even cracking.

2. Sensitivity to wind 

The shielding gas used for this process can be easily blown away when welding takes place outdoor. Even inside, a fan or a wind draft of 5 mph can be enough to induce porosity in welding.

3. Limited positions

High heat input of a Mig welder and fluidity of welding puddle aren’t suited to overhead or vertical welding. Whilst some welders never think of welding in one of those positions, take this factor into account when deciding whether to buy a Mig welder to ensure it can accomplish all of the tasks planned for it.

4. Lack of fusion 

Owing to the ability to weld at low currents, Mig welding has the potential for incomplete fusion welding defect when operating in short-circuit mode. Ensure you always apply the proper procedure for the thickness of material you’re welding. 

5. Portability problem

Moving the welding equipment mayn’t be that difficult though, you also have to deal with the high pressure cylinders containing the shielding gas. Proper care must be taken.

6. Open arc process 

Like most welding processes, Mig welding is an open arc process. Proper care must be taken to shield the welder and by-standers from harmful UV rays.

7. Fast cooling rates

The welded metal will cool at higher rates because they are not covered with slag when the weld is completed.

8. Shielding gas

It can take time to replace the shielding gas bottles, and they can get in the way whilst welding.

9. Time for metal preparation

Before you weld with a Mig welder, the material has to be free of dirt or rust for a good weld got and safety’s sake.

10. Difficulty getting into tight places

The gun is hard to get into tight places.

11. The equipment is pretty complex

The equipment is rather complex, since this process require a direct current source, a constant source, flow of gas, and continuously moving wire electrode. Also, electrodes are available in various sizes and made from numerous metal types to match the welding application.

12. Learning curve associated with Mig welding

As the actual technique employed is different from conventional welding practices, there is learning curve related to Mig welding, even for veteran welders. For instance, Mig welders need push the welding puddle along the seam and away from them.


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