Welding Gas

Welding gas (shielding gas) is used in MIG/MAG welding to have a controlled atmosphere for plasma arcs and to shield the liquid weld pool from oxygen. Stick welding electrodes don't need extra shielding gas as the flux coating on the electrode serves a similar purpose. The gas is commonly sold in heavy steal bottles also called cylinders. The containers need thick walls as the gas is compressed to 200 or 300 bar in the most common offerings, allowing them to hold the the 200x or 300x of their real volume.

Types

There are a lot of different gas mixes with different properties, see this overview on Wikipedia.

For our Einhell BT-GW 150 we needed something that was not too expensive, commonly sold and easy to use. Therefore we stock argon with 18 % CO₂.

Dangers

• risk of explosion:
  • cylinder can fall over and burst - needs to be tied to a stable structure
  • cylinder must not be subjected to heat
• risk of suffocation:
  • large amounts of welding gas can replace the oxygen near the ground as some are heavier than air