Do I Need Flux for Gas Welding Steel?

Gas Welding Types

• Most types of welding utilize gas of some kind, and all can be used for welding various types of steel. Oxy-acetylene welding utilizes a combination of oxygen and acetylene to generate heat. MIG and TIG welding refer to metal-inert-gas and tungsten-gas welding, respectively. Each of these types of welding utilizes gas in the heating process, and all may use flux if assistance is needed to smooth the joining of the metals.

Types of Fluxes

• Different types of fluxes can be used when welding steel. Paste-type fluxes are used to weld steels when very high temperatures are required to bond hard steel varieties. This helps form welds in steel that are hard to weld such as that used in industrial equipment. Powdered fluxes are also used when welding some types of steel. Usually, these are used with steel alloys or stainless steel.

Using Flux

• Flux is applied to the metal to be heated before the heat source starts to melt the metal. The flux chemically reacts with the steel as it begins to change under the heat to prevent oxidation from forming. Oxidation corrupts the purity of the weld and makes the joint weak. The residue of the flux needs to be cleaned off of the project once the welding is complete and the metal has cooled.

Flux-Core Welding

• One type of gas welding used on stainless steel incorporates flux directly into the electrode. Sometimes called FCAW, or Flux Cored Arc Welding, this is a type of MIG welding technique that uses special electrodes to provide smooth welds when working with stainless steel and other materials. Stainless steel is a somewhat difficult material to weld normally, and the flux-cored electrode helps stabilize the arc and shield the weld. Smoke can be a problem with this type of welding, so a fume hood is often used to reduce the smoke.