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If you are looking to weld aluminum, but do not want to use a TIG welding machine, then it is possible that you can MIG weld aluminum with DC.
Mig welding is a process where the metal is heated up and melted using an alternating current. This allows for greater control over the heat level used.
Can You Mig Weld Aluminum with DC?
The answer is yes, but it will require a few more steps. Luckily, here are the steps you can follow.
Step One: Prep Work
Preparation is the most important part of MIG welding aluminum. You must first ensure that your tungsten electrode and wire are clean, free from oil or grease, and have no moisture on them.
Also, make sure to use dry argon gas for shielding purposes. If you used flux core wire, be mindful of how much it is compressed and how much it is touching the workpiece.
Step Two: Enable AC
To MIG weld aluminum, you will need to use an alternating current. This is accomplished by switching the polarity of your power source or changing it to an inverter-style machine.
Welders emit a constant voltage across their electrodes when welding steel and solid materials with direct current, but aluminum cannot do this because there are no positive ions in its molten pool.
The only way for you to have good electrical contact between wire and tungsten electrode while melting aluminum is if both ends are positive, which can happen through pulsed DC (AC) settings that alternate the direction of electric flow every half cycle. This will allow for a strong arc to form and the electrode to remain clean.
Step Three: Mig Welding Technique
When welding aluminum, you must use short bursts of wire as opposed to maintaining a constant flow like what is done when welding steel.
In addition, overlap each pass by 50 percent in order to ensure complete fusion with the base material. Aluminum requires 25% less voltage than other metals, so keep your machine on low power settings throughout the process unless instructed otherwise by an instructor or another source that knows more about MIG welding than yourself.
Step Four: Cleaning
As mentioned earlier, cleaning your tungsten electrode and wire is essential in the MIG welding process. Aluminum creates a dirty slag that can cause you to lose electrical contact with the tungsten, leading to poor arc starts or no start at all.
Take time between each pass of aluminum to clean your electrode using a brass brush dipped in flux core remover, then use compressed air to blow away any leftover residue before restarting the machine for another round of welds.
Step Five: Safety First!
When MIG welding aluminum, you must ensure safety first and foremost. If using a gas shield, be sure to have your regulator set between 20-40 psi because higher pressures can lead to porosity in the weld puddle, while lower pressures may not provide enough protection from impurities such as moisture or oil, which could cause problems down the road when it comes time for paint removal.
In addition, make use of gloves and proper clothing when MIG welding aluminum so that no loose ends are exposed. They could come into contact with hot surfaces resulting in burns or other injuries. Lastly, keep all bystanders clear of where you will be working and try having them stay at least ten feet back until after you start your weld.
Which type of wire do you use for MIG welding aluminum with dc?
When you are MIG welding aluminum with dc, you should use a specialized wire that is made of pure tungsten. This will allow for maximum voltage to flow through the machine while still producing an arc strong enough to melt down your electrode and base metals without too much spatter or contamination from impurities.
You can also try using pulsed direct current, which alternates between positive polarity every half cycle in order to create good electrical contact at both ends of the tungsten/wire pairing allowing for proper fusion during each pass.
What are some safety precautions that need to be taken when mig welding aluminum with dc?
Safety should be taken very seriously when working with aluminum. This is because it emits fumes that can cause you to become dizzy or lightheaded if inhaled for prolonged periods of time, so always wear a mask and protective clothing before beginning the welding process.
Aluminum also heats up much faster than other metals, which could result in skin burns unless proper protection is worn throughout this part of the process, including gloves and aprons made from thick material like leather.
Make sure there are no bystanders around your work area until after you have started MIG welding to ensure they do not accidentally come into contact with hot surfaces resulting in injuries similar to what would happen if someone got too close during tig welding procedures. You can also check our post on whether you can weld on a wood table if you are interested in reading it.
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