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ALUMIN-351 N
Unitor ALUMIN-351 N is used for joining and building up aluminium parts with a thickness of more than 2 mm sheets, sections, tubes, pistons, castings (covers), gangways, etc. When welding materials more than 3 mm thick, a 60° V-groove and an air gap of 1–3 mm should be used.
Grooves and the surrounding area must be thoroughly cleaned. Thin parts should be backed up before welding.
NB. When welding with Aluminium electrodes: Arrange suitable ventilation or use Fresh Air kit mounted in face shield.
Cover plate ears welded back on
Use DC, positive polarity setting. Large parts or castings should be pre-heated to approx. 300°C. Hold the electrode almost vertically the workpiece, the tip at a slight angle to the weld direction. It is preferable to weld in the flat position. Use as short arc as possible and weld rapidly. If welding is interrupted, remove the slag and overlap the end of the bead by about 1 cm when re-striking.
3.01
All slag must be cleaned off the finished weld with brush and water. Aluminium electrodes absorb moisture very easily and must be stored in a dry, preferably moisture-controlled, place. Aluminium or magnesium?
It may be difficult to determine whether a part is aluminium or magnesium. Magnesium parts must not be welded (magnesium bomb!). Use the following test to determine whether a part is aluminium or magnesium: File a few shavings onto a small piece of paper. Hold the paper over a flame. If the fillings spark or seem to explode in the flame, the material is magnesium. If there are only a few sparks here and there, and most of the fillings just glow, the material is aluminium alloyed with magnesium, and may be welded.
Hold the electrode almost at right angles to the workpiece, or at a slight angle to the weld direction Note: Use the shortest possible arc.
Joining a cast aluminium cover. Such parts should be pre-heated to approx. 300°C if possible
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