Due to the circumstances mentioned above the surface treatment of base metals and ﬁ ller wires plays a much bigger role than for instance with steel. The question if cleaning prior to welding is necessary can only be answered in one way: In case that low porosity, high strength and constant welding joints are the target then thorough cleaning according to tested, ﬁ xed and reproducible processes is necessary.
We have put together some basic rules for storage, cleaning, joint preparation and welding.
Storage and handling base materials
Sheets and proﬁ les are to be stored vertically and with a sufficient distance in order to get air circulation and to prevent contact points to each other. The storage must be covered and preferably heated whereas the temperature should be constant. Controlled humidity would be a positive option.
Storage and handling filler materials
A heated room for storage with constant temperature and if possible controlled humidity as well is of great importance. Prior to welding the ﬁller materials should be stored in the same environment than the base materials without opening the boxes in order get the same temperature. Protection against dust and any other pollution must be given at any time.