What is Back Gouging in Welding?

Back gouging is the process of removing weld metal and base metal from the other side of a partially welded joint to ensure complete penetration upon subsequent welding from that side.

What is the purpose of back gouging?

The purpose of back gouging is to prevent incomplete fusion or lack of penetration (LOP) defects, which can lead to weld failure.

Two main methods of back gouging

There are 2 main methods of back gouging: mechanical and chemical.

Mechanical back gouging is typically done with an air carbon arc cutting (CAC-A) torch, although other tools such as:

grinding wheels,
milling cutters,
and chisels can also be used.

Chemical back gouging, on the other hand, involves using a chemical agent to remove the weld metal and base metal.

The most common method of back gouging is mechanical back gouging with an air carbon arc cutting torch. This method is fast, efficient, and provides a good finish. However, it can be dangerous if not done properly, as the air carbon arc cutting torch produces high temperatures and sparks that can cause burns or fires.

Chemical back gouging is a safer alternative to mechanical back gouging, as it does not produce high temperatures or sparks. However, it is generally slower and less efficient than mechanical back gouging.

Back Gouging Process

There are 4 steps in the back gouging process:

Select the appropriate back gouging method (mechanical or chemical).
Select the appropriate back gouging tool (air carbon arc cutting torch, grinding wheel, milling cutter, chisel, etc.).
Set up the back gouging equipment.
Perform the back gouging operation.

Good to know

1) What is welding gouging?

Welding gouging is a process in which an arc is used to melt and remove metal from the base material. Gouging can be done with either an electrode or a carbide-tipped tool.

2) What is a backing weld?

A backing weld is a weld that is placed on the back side of a joint to support the main weld.

3) What is back chipping in welding?

Back chipping is the process of removing weld metal and base metal from the other side of a partially welded joint to ensure complete penetration upon subsequent welding from that side.