Slag in Welding
Slag in welding is a nonmetallic byproduct from the flux coating on welding electrodes or filler materials. As the weld area cools, the remaining flux solidifies over the weld bead. Since it leaves a poor surface finish, slag must be removed by grinding, brushing, flame cleaning or chipping before applying any coatings. Welding over unremoved slag results in poor bonding and a defective weld.
Welding Techniques
Shielded Metal Arc Welding (SMAW)
Shielded metal arc welding (SMAW), also called stick welding, uses an electric arc between a flux-coated consumable electrode and the base metal. SMAW is compatible with most metals and used in many applications like construction, shipyards, and repairs. The flux coating shields the weld from contamination.
Metal Inert Gas Welding (MIG/GMAW)
MIG welding (GMAW) creates an arc between a consumable wire electrode and the workpiece, melting and fusing them. MIG welding is faster than SMAW but requires more equipment like a welding gun and shielding gas.
Proper welding technique allows slag inclusions to float to the top of the weld pool. After cooling, slag must be removed before applying any coatings.
Welding Slang
Slang in welding refers to common words and phrases used by welders to communicate simple messages quickly without stopping work. For example:
- "bugger" means a welder’s helper
- "golden arm" means a highly skilled welder
- "drinking hand" is a welder who drinks excessively
Using slang improves efficiency in the welding workplace.