Page 114 - CITS - Welder - Trade Practical

WELDER - CITS

Skill Sequence

Square butt joint on aluminium sheet of 3mm thick

Objectives: At the end of this exercise you shall be able to
• prepare and weld square butt joint on aluminium sheet of 3mm thick.

While preparing square edges make notches on the edges to be joined. Fig 1

Fig 1

Since setting a strict neutral flame is difficult a very slight carburizing flame is set for welding aluminium.
While using leftward technique, the blow pipe angle will be reduced gradually as the welding progresses. Fig 2.
As there is no colour change when aluminium melts, watch carefully for any shrinking of oxide film on the surfaces
of the base metal which indicates the starting of base metal melting.

Fig 2

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CITS : C G & M - Welder - Exercise 21