What's better for beginner to weld aluminium - TIG or MIG?

Aluminium alloys are ubiquitous because they provide engineering materials with good strength-to-weight ratios at reasonable cost. Also some alloys have a vast corrosion resistance and both thermal and electrical conductivity. Furthermore, normally having a somewhat low strength, some of the complex alloys are almost equivalent to steels in those terms. So being able to weld aluminium is one of the best opportunities nowadays for everyone who works with metals. At least, just in case.

However, aluminum welding is utilizing some other techs, shielding gases, specifications and other stuff like some specific preparations before welding and some post-processing after welding. Furthermore, if you want to do all that complex stuff with the welder that’s suitable for steel, than you’ll need some additional things. And in our article we’ll state some of those things clear for beginners who want to do some aluminium welding.

Differences between welding aluminium and welding other metals

Before reading about all the stuff about aluminium welding processes, it's important to understand some of the specific thus somewhat difficult and complicated stuff that’s strongly related to it. Aluminium welding itself pose a variety of differences, including:

• Higher thermal conductivity. This results in higher dissipation of heat compared to welding other metals, thus it can make welding itself kind of difficult or result in parts' distortion, due to a higher heat required.
• Dissolving hydrogen. Hydrogen is dissolving very fast when it's in contact with molten aluminium. Due to that hydrogen is being absorbed in the weld pool, thus the molten material is becoming porous because of hydrogen bubbles when solidified.
• Oxide layer. All aluminium alloys, without any exceptions, have an oxide layer, which has a melting point that is three times higher than the alloy itself has. If not removed, it can cause fusion defects, reducing weld strength. Thus oxide layer must be surely removed with a wire brush during preparations.

In addition to those difficulties, there are some less complicated but important things. One of those things is that aluminum alloys can be welded without filler materials as well as some of those alloys can't. Obviously, you must also select the correct filler, because mispicked material will cause a weld failure. Furthermore, you must remember about filament feeding, because if there’s a mechanical feeding, then you almost surely will need to use some specific tools and systems. Otherwise, without something like push-pull gun, your filler metal will tangle, especially if it’s thin.

What’s better - TIG or MIG aluminium welding?

Actually, there are two popular welding processes in case of welding aluminium. First and the most popular one is the Tungsten Inert Gas (TIG) welding or Gas Tungsten Arc Welding (GTAW). Another popular one welding process is Metal Inert Gas (MIG) welding, also known as Gas Metal Arc Welding (GMAW).

We’ll compare those two processes using some popular models of each kind. Square Wave TIG 200 by Lincoln Electric and Forney 242 Dual MIG Welder. First one is using GTAW and the latter is utilizing GMAW, so it’ll be easy to compare them in terms of welding process.

TIG Welding

So, first things first, Square Wave is using, as it’s obvious, tungsten inert gas and can be feeded independently and manually without any additional mechanical feeders. Filament is manually applied into the puddle by your own hand thus making the whole process extremely precise and clean. As an addition to the basics, Square Wave TIG 200 has a very precisely adjustable AC Frequency Control and an AC Balance. It allows you to do some more cleaning on dirty aluminum alloy or do some welding with some thick metals.

MIG Welding

Forney 242 Dual, being opposite to Square Wave, is utilizing GMAW and has higher deposition rate and travel speed than its counterpart. But it has a mechanical, less precise, filament feeding system, thus having a spool gun for feeding the weld with a filament wire. Nevertheless, it’s somewhat a universal tool due to being able to weld steels after flipping a dedicated switch for changing welding mode and changing a filler wire.

What’s better for a beginner?

If you’re a novice in welding aluminium than your choice is GTAW system. It’ll allow you to achieve higher precision and gain some skill through the process. Lincoln Electric Square Wave TIG 200 will be one of the best choices for a beginner among those systems despite being somewhat expensive. But it’s obvious to be ready for expenses if you’re planning to weld and learn how to do it a professional way.

The GMAW systems, as it seems, are for skilled ones who know how to do the stuff and welding aluminium with the same precision as welding steels. Due to its complexity it’s not for a beginners for sure, especially meaning that it has a push-pull gun or a spool gun, mechanically and independently from its user adding filling material to the weld.

So having the same price, TIG (GTAW) welders are really useful for everyone who’s a starter at welding aluminium. Being easier to use, more precise in terms of applying filling material and very useful at welding some really thick metal layers, those are real lifesavers for everyone who want to get along with the aluminium welding before moving to some pro stuff.