Aluminum Casting Fluidity

Aluminum is thin when liquid and flows well into molds. In welding, this means the weld pool is very fluid and you have to work quickly and controlled with the torch or electrode, otherwise the pool will run away from you. The exact fluidity depends heavily on the alloy – some are more viscous, some run like water. If the pool is too thin, it helps to reduce heat input and use shorter welding intervals. Make sure the seam is clean and free of oxides, because they hinder the pool from merging and make the seam porous.