Operation Manual

3. USE

NOTE! It is forbidden to weld in places where there is a danger of re or

explosion!

3.1 WELDING PROCESSES

3.1.1 Manual Metal Arc welding (MMA)

In manual metal arc (MMA) the welding ller material is melted from the

electrode to the weld pool. Rate of welding current is selected on the basis of

electrode size used and welding position. Arc forms between electrode tip

and welding piece. The melting electrode coating forms gas and slag, which

protects the weld pool. Slag solidied over the weld is removed after welding

e.g. with a chipping hammer.

3.1.2 TIG welding

In DC TIG welding, the arc between tungsten electrode and the welding

piece melts the welding piece, thus forming a weld pool. Arc and electrode

are shielded by an inert shielding gas (Argon). If necessary, ller is used. Filler

wire is fed into the weld pool from the outside of the arc. The ller wire and

the welding current level are decided according to the base material type

and thickness, joint form and welding position.