The three primary categories of electrodes—cellulose, rutile, and basic (low-hydrogen)—obtain their name from the coating type. Electrode coatings help optimise performance for various applications by influencing how quickly the slag freezes; penetration (deep, medium, or mild); and deposition rate. The coating also contributes to good arc initiation, easy restrikes, puddle control, and a stable arc with minimal spatter.
Cellulosic. The coating on a cellulosic electrode is relatively thin (12 to 15 percent of the electrode’s diameter) and produces a thin, easily removable, fast-freezing slag suitable for all-position welding, including vertical-up and vertical-down. Cellulosic electrodes provide a digging/driving arc with deep penetration. The weld puddle wets and spreads well, demonstrates excellent mechanical properties, and has distinctive ripples. Cellulosic electrodes include E6010, E7010, and E6011, which are typically used for pipe, barges, farm repairs, maintenance work, and dirty plate.