Frequent mistakes you do MIG welding
Welding is the process by which materials, metals and plastics can be fused together. Common types of welding are arc welding, gas welding and resistance welding. In this process, the materials are melted at the point that has to be welded and then joined. An energy source such as electric arc, gas flame, laser beam, electron beam, and ultrasound are used for welding. The commonest type of welding is arc welding.
MIG welding or Metal Inert Gas welding is a kind of gas metal arc welding. In this through a welding gun, continuous and consumable wire electrodes and shielding gas are fed. Generally direct current is used with constant voltage. Alternate current can also be used. This method was first used for welding aluminum, but was later also used for steel as it considerably lessened the time taken for welding.
MIG welding has many advantages.
- It is easier to learn.
- It is possible to make longer welds without having to stop and start again.
- There is less of cleaning needed after welding is done.
MIG welding has some disadvantages.
- It leaves behind an oxidized weld deposit.
- The arc is unstable.
- There is weld porosity.
Some of the frequent mistakes that you do in MIG welding
- The parts that have to be welded have to be very clean. Paint and dirt should not be there when the part is being welded. This a general mistake made by a beginner. If the parts and the surface to be welded are not clean, the weld will not be proper and a bad weld will be the result.
- While doing MIG welding, it is necessary to use the right type of gas. Some people might tend to use cheap variety of gas. Just using carbon dioxide will be cheap, but a mixture of gases will produce the desired result and good welding.
- If the polarity is wrong, the weld bead that is produced will not look good.
- The contact tip sizes should be right.
- The speed should not be too fast or too slow.
- During welding, the wind should be blocked and should result in proper shielding.
- If the welding is very cool on a big piece of material, proper welding will not take place.
- The right size of welding machine should be used. A very small machine for a very large material will not do the work properly.
- The components of the wire feeder, like the liner, contact tips and other parts should be maintained properly to give the desired result of proper welding.
- The filler material should have the correct tensile strength. If this is not matched correctly, the result will not be right.
So, it is necessary to follow a few rules to get MIG welding right.
First, you should see that the joints are clean. This can be done with a wire brush or a grinder. Otherwise you will not be able to do MIG welding.
Second, you should set up the MIG welding machine properly. It has three settings.
- Wire speed feed and
- Shielding gas flow rate
On the inside panel of the MIG welder there will be chart which will give you the correct setting for different materials depending on their thickness. The shield gas flow rate should be protected from the surrounding air.
Third, you should use the proper welding technique. The welding technique for all types of welding is the same. People use the whipping technique with a back and forth motion, a circular motion or the weave technique with a side to side motion. Whichever technique is used, the wire stick out should not be more than three- fourth of an inch. If this is not the case, the shielding gas will not be able to do the work correctly.
If these mistakes are taken care of, MIG welding will be easy to do