Welder World Blog

It is an undeniable fact that welding aluminum items calls for some professional expertise and special skills. Even welding enthusiasts who have past experience in successfully welding steel will find aluminum welding challenging. The reason is simple – it is difficult to feed aluminum wire which is soft. Furthermore, wire diameters and machine settings generally used for steel may not be appropriate for aluminum.

The truth is with some practice, you will be able to tackle aluminum welding jobs such as grills, railings, backyard furniture, boat docks and even decorative elements – using a compact MIG welder. Depending upon your needs, you can buy the right type of MIG welder.

A 115 volt wire feeder welder can handle jobs that range from 22 to 12 gauge and with moderate pre-heating, you can probably weld even up to 1/8″ thickness. The only precaution is the preheating should not exceed 250 degrees F maximum. You can also opt for a 230 volt machine which can weld from 22 gauge up to 3/16″. If proper preheating is done you can go up to 1/4″. If your application is broader range of aluminum thicknesses, then it is worth investing in the 230v machine.

However, it needs to be stated that a compact MIG welder of 115 volt and 230 volt models are in order only for occasional aluminum jobs. As regards heavy duty aluminum, you must buy a welder that has greater than 200 amps output.

The next question you need to address when selecting a welder is whether you want a continuous or tapped voltage control model. Please understand that a continuous voltage control model lets you set an infinite range of voltage within the rating of the machine. This facilitates your adapting the voltage to your particular applications and skill level. If you want to spend less, opt for the tapped control unit. This machine has a rotary switch with four or five fixed voltage choices. This model will be adequate for most applications.

As already stated earlier, MIG welding aluminum is different from welding steel and this also applies to shielding gas requirements. For aluminum, 100 percent argon is the preferred choice, whereas steel welding calls for a mixed gas or 100 percent CO2 gas. Of course, for this reason no special equipment is needed – your existing regulators and gas hoses can be used for both pure blends and mixed gases.

The oxide layer needs to be removed from the aluminum immediately before welding. The edges of the aluminum should be cleaned with a file. It is best to use a new wire brush that hasn’t been used on steel, and to brush in a single direction so the oxide is not rubbed into the aluminum.

Please know that all MIG welding on aluminum materials requires electrode positive polarity. If you are switching your wire feed welder between processes, do not forget to switch your polarity. You will certainly not succeed in obtaining good results attempting to weld on aluminum with a steel wire electrode.

There is a trick to properly loading aluminum wire into a wire feed welder and this comes with regular practice. As you are welding aluminum, keep the gun cable as straight as possible to minimize feeding restrictions on the soft aluminum wire. Ensure that there are no bends in the gun cable that may make the wire kink and feed poorly.

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