Aluminum Welding Guide

Good cleaning practices are always important when welding aluminum. The level of cleanliness and metal preparation required for welding depends on the level of quality desired in the welds. Suitable preparation prior to welding is important when fabrications are required to meet the weld quality requirements of manufacturing codes such as AWS D1.2.

High quality welds are far more difficult to achieve in aluminum than in steel. Aluminum has a much greater potential to develop quality problems such as lack of fusion, lack of penetration, and porosity, than does steel. The tough oxide surface film on aluminum can create lack of fusion problems and must be controlled. The high thermal conductivity of aluminum can create lack of penetration problems. The high solubility of hydrogen in molten aluminum can create porosity problems and requires that all moisture and hydrocarbons be eliminated before welding. The thickness of the oxide film on aluminum must be controlled and prevented from hydrating due to the presence of excessive moisture.