5 Tips for MIG Aluminum Welding

welder with mask heating metal

MIG aluminum welding is both a science and an art. You can learn the technique, but mastering it is simply a process of trial and error. However, there are a few tips that can make your MIG aluminum welding practices easier and faster.

Correct Wires

You always need to use the correct welding wire for the material you’re welding. With MIG aluminum welding, always use aluminum wire. For thinner materials, you’ll achieve the best results by using a thinner wire. Where the metal is thicker, use a broader wire and a more powerful welder.

The hub tension on the wire feeder and the drive roll pressure both need to be tight enough to feed the wire, but neither should be overtightened. When you’re not using the welding wire, keep it in a clean, dry place. This stops grease forming on the wire which can lead to a poor weld.

You should use a 4043 aluminum alloy electrode for MIG aluminum welding in preference to a 5356. The 5356 is stiffer wire and it’s often easier to feed, but it can be harder to achieve a good weld with it.


Always wear a welding mask. An electronic one is preferable although they inevitably cost more. The great advantage is that you don’t have to put a hand up to lower the visor. They can be purchased with variable density masks which can be useful if you’re welding in different lights. Another important investment is in good, heavy safety gloves. These can save on the number of scars you could receive on your hands.

It’s also important to be comfortable when you weld. There will be times when you’ll need to be in cramped positions, but you’ll weld better if you can stand or sit freely and easily. Keep a bucket of water and a fire extinguisher handy, in case of a fire. Fires inevitably occur and it is best to be cautious.

bright firey welding

What Type of Welder?

For light welding, you can probably use a 115 volt machine for MIG aluminum welding. However, this will only weld up to 22 gauge. If you are be working with greater thicknesses of aluminum on a regular basis, you should spend the extra money and buy a 240 volt machine which is capable of MIG aluminum welding of materials up of 3/16 inch.

Shielding Gas

For MIG aluminum welding, you should always use 100 percent argon gas. The regulator on your machine and hoses should be capable of handling this. MIG aluminium welding needs an electrode positive polarity. Don't use an electrode negative polarity for welding alunimum.


When you’re MIG aluminium welding, you’ll achieve a better result with deeper penetration by using a pull technique. A push technique, on the other hand, will give you less penetration and a wider bead. The electrode should extend from the tip of the contact tube by ¼ inch to ¾ inch. Always keep the gun as straight as possible when you’re welding and use both hands to steady the gun for maximum control. If the contact tip becomes blocked, replace it.