Weld preparation

Before workpieces can be welded by means of gas fusion welding or arc welding, the weld edges must be cleaned. Oil, wax layers, paint or scale must be removed. The welding points must also be metallically clean, as without these preparations the welds would not last.

Lathing and other mechanical (chip removal) methods are very suitable methods for cleaning the welding points. Attention must be paid to ensuring that the tools always have sharply ground cutting edges. Avoid lubricating the metal. Therefore, no coolants or lubricants may be used.

If weld preparation is carried out on aluminium, attention must be paid to ensuring that the abrasive has been explicitly approved or recommended for aluminium by the manufacturer.

Sand blasting is also a possible method for preparing the weld. However, in this case attention must be paid to ensuring that the blasting material (grit or shot) is appropriately matched with the material to be welded. The manufacturers usually provide relevant information.

Manual cleaning is also a possible method for preparation of the weld. Only stainless steel brushes should be used for this. Other brushes can cause inclusions of carbon steel to occur in the parent metal. The diameter of the wire should be between 0.1 and 0.25mm. If the wires are too thin they smear the dirt and if they are too thick they cause deep scratches on the surface or edge to be welded.

Milling is also a very good variant of weld preparation, as very clean edges result. On request, at this stage chamfers in diverse sizes and angles can be machined on the weld edge. This makes it easier for the welder to join assemblies.