Smootharc 180 Multiprocess - Page 49

Porosity in Weld Deposit
Cause Solution
Entrapped impurities, hydrogen, air, nitrogen, water
vapour
Do not weld on wet material.
Defective gas hose or loose connection Check hoses and connections for leaks
Filler material is damp (particularly aluminium) Dry ller metal in oven prior to welding
Filler material is oily or dusty Replace ller metal
Alloy impurities in the base metal such as sulphur,
phosphorous, lead and zinc
Change to a di󹟽erent alloy composition which is weldable. These impurities can cause a
tendency to crack when hot
Excessive travel speed with rapid freezing of weld trapping
gases before they escape
Lower travel speed
Contaminated shield gas Replace the shielding gas
Inadequate shielding
Cause Solution
Gas ow blockage or leak in hoses or torch Locate and eliminate the blockage or leak
Excessive travel speed exposes molten weld to
atmospheric contamination
Use slower travel speed or carefully increase the ow rate to a safe level without creating
excessive turbulence. Use a trailing shield cup
Wind or drafts Set up screens around the weld area
Excessive electrode stickout Reduce electrode stickout. Use a larger size nozzle
Excessive turbulence in gas stream Change to gas saver parts or gas lens, lower ow rate if possible
49BOC Smootharc 180 Multiprocess operating manual