Gasless MIG?

In the welding industry it is common to hear discussions about processes run without shielding gas, often labelled “gasless MIG”. But is that really MIG? Let us look more closely at the terminology and at what lies behind the technique.

What is “gasless MIG”?

The term “gasless MIG” is usually used to describe the use of self-shielded flux-cored wire. This type of wire contains an internal flux which, when heated during welding, undergoes chemical reactions that generate gaseous shielding around the arc. That removes the need for an external shielding gas such as argon or CO2, which is what conventional MIG welding uses.

Schematic of how self-shielded flux-cored wire (gasless) works:

• Read the full article on the MIG (solid wire) process here.

Advantages of self-shielded flux-cored wire

Self-shielded flux-cored wire offers several advantages, especially in environments where gas cylinders are impractical:

• Portability: with no gas cylinders required, the equipment is easier to transport and use in different locations.
• Greater tolerance to wind: it can be used for field welding with a lower risk of defects than MIG or gas-shielded flux-cored wire.
• Ease of use: doing away with shielding gas simplifies machine setup and speeds up the process.
• Versatility: ideal for outdoor work or anywhere shielding gas control is complicated.
• Easy tacking: it can replace TIG and stick welding, using a portable machine (shown at the end of this article).

Disadvantages of self-shielded flux-cored wire

• Lower deposition rate than gas-shielded flux-cored wire.
• Slightly more difficult to weld with.
• For applications with low-temperature impact requirements, this consumable may not be suitable.

Wire specification

This process uses the wire: AWS A5.20 E71T-11

Conventional gas-shielded flux-cored wire, by contrast, is AWS A5.20 E71T-1C (pay close attention when purchasing).

Portable machines for small welds and tacking

Some machines that stand out in this application and that we recommend:

These machines are very light and compact, take a 1 kg spool of Ø0.8 mm wire and can be carried anywhere easily - but they are only suitable for tack welds and short welds at low parameters.

Recommended wire

Direct purchase link for the wire: