Welding
Overview
Welding is a core activity in the fabrication shop; it is used to prepare joints for connection on site and for the attachment of other fixtures and fittings. Different welding techniques are used for different activities within the fabrication shop
Shot blasting
Shot blasting is another important part of the fabrication process. This is essential to provide a suitably clean finish for welding and also produce a keyed surface ready to accept paint. Shot is fired at the steel.
Shielded metal arc
Shielded metal arc welding is used to temporarily join or tack weld components during fabrication prior to full strength welding. Shielded metal arc welding employs a "Stick" type electrode covered with a flux coating.
Metal active gas
Metal active gas (MAG) is used for continuous strength welding. MAG welding employs a continuous solid wire electrode carrying current. This is supplied by a power source and fed through a "Gun" by a roller wire-feeder.
Submerged arc
For welding long pieces of steel together to fabricate structural beams, submerged arc welding is used. In Submerged arc welding (SAW) a power current is applied to a continuous wire electrode.
Non destructive testing
Non destructive testing (NDT) is carried out to ensure that welds are free from unacceptable defects such as cracks and inclusions. The main NDT techniques are magnetic particle testing
