What does joint preparation involve in GMAW?

Joint preparation in Gas Metal Arc Welding (GMAW) is critical because it sets the stage for a successful and strong weld. The correct aspect of joint preparation involves cleaning the base metal and removing contaminants. This process ensures that there are no oxides, rust, oil, or other foreign materials that could interfere with the welding process. Contaminants can lead to poor weld quality, defects like porosity, and ultimately, a weaker joint. Properly prepared surfaces allow for better fusion between the materials, resulting in a more robust bond.

While joining two pieces of metal is certainly a part of the welding process, it follows the preparation stage—it is not the preparation itself. Applying a coating to the metal could actually hinder the welding process unless it is specifically related to the metal type and purpose, such as certain pre-weld treatments. Measuring the angles of the joint, on the other hand, may be important for specific applications but does not pertain directly to the preparation of the surfaces prior to welding. Thus, ensuring the base metal is clean and free of contaminants is the most critical aspect of joint preparation in GMAW.