Understanding plasma gouging vs carbon arc and air arc gouging

Plasma gouging

Plasma gouging – removing metal using a plasma arc – is similar to plasma cutting. A plasma arc between the torch and the workpiece melts the metal, and a gas jet blows away the molten metal. However, in gouging, specially designed consumables produce a somewhat wider arc, the torch is held at an angle, and only some of the material is blown away.

Plasma gouging works on any conductive metal, including mild steel, stainless steel, aluminum, and copper. With a bit of practice, it is possible to achieve smooth, clean, consistent gouges. Compared to other processes, such as carbon arc gouging, plasma gouging can reduce the amount of noise and debris in the work environment.

Gouging can be performed freehand or with a mechanical aid such as a track cutter. It can also be done on fully automated CNC cutting tables.

Trends in plasma gouging

  • Need for faster operating speeds and less time spent on primary or secondary grinding work
  • Regulatory requirements and work environment concerns requiring reduction in noise and debris levels
  • Requirements for reduced contamination of the workpiece — i.e. no carbon contaminates
  • Safety concerns when using incumbent methods such as oxyfuel or carbon arc
  • Desire to reduce operator training time and shorten the learning curve
  • Spot weld removal on automotive body panels made of high strength steel

How plasma gouging works

The plasma gouging process removes any amount of material from a workpiece regardless of shape or rate, without actually severing or piercing the material. Just as in plasma cutting, a plasma arc is formed between a negatively charged electrode inside the torch and a positively charged workpiece. Heat from the transferred arc rapidly melts the metal, and a high air pressure blows the molten metal away. In order to prevent cutting the metal when gouging with plasma, gouging specific shields and nozzles should be used.

In addition, many plasma systems have a dedicated operation mode for gouging that adjusts the amount of pressure traveling to the torch. You can still gouge with the system set to cutting mode, but it’s advisable to use gouging consumables to help keep the arc from piercing or severing the workpiece.

Gouging consumables

For Powermax® systems there are different gouging consumable options to choose from based on desired gouging results and operator preference.

  • Max removal gouging shields allow for aggressive metal removal, achieving deep gouge profiles and extreme metal washing applications
Max removal gouging
  • Max control gouging shields allow for more precise metal removal, achieving shallow gouge profiles and light material washing applications
Max control gouging
  • Precision gouging nozzle and shield for removing small amounts of metal or weld at very low output current
Precision gouging
HyAccess gouging

Learn more about Powermax plasma systems

Air plasma vs. other gases

Depending on the plasma system, a number of different gases – including air, nitrogen, oxygen, an argon/hydrogen mix, and other combinations – can be used when gouging with plasma arc. However, it’s a good idea to check the operator manual first to make sure the gas you want to use is compatible with your particular plasma system. Here are some general rules when deciding on which gas to use:

  • Compressed or bottled air provides the lowest cost of operation and acceptable quality on mild steel, stainless, and aluminum.
  • An argon/hydrogen mix can produce a clean, bright, smooth gouge on aluminum and stainless.
  • Nitrogen gas is good if you want to extend the life of your consumables.

Change the way you work.

New Powermax SYNC series air plasma system from 65–105 amps, featuring single-piece cartridge consumable platform and automated process setup.

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Learn more about real life plasma gouging applications

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