Smootharc 180 Multiprocess - Troubleshooting and Fault Finding; TIG;MMA functions

11.0 Troubleshooting and Fault Finding
11.1 TIG/MMA functions
Excessive electrode consumption
Cause Solution
Inadequate gas ow Increase gas ow
Inadequate post gas ow Increase post ow time to 1 sec per 10 amps
Improper size electrode for current required Use larger electrode
Operating of reverse polarity User larger electrode or change polarity
Electrode contamination Remove contaminated portion, then prepare again
Excessive heating inside torch Replace collet. Try wedge collet or reverse collet
Electrode oxidising during cooling Increase post ow time before turning o󹟽 valve
Shield gas incorrect Change to proper gas (no oxygen or CO
2
)
Erratic Arc
Cause Solution
Incorrect voltage (arc too long) Maintain short arc length
Current too low for electrode size Use smaller electrode or increase current
Electrode contaminated Remove contaminated portion, then prepare again
Joint too narrow Open joint groove
Contaminated shield gas. Dark stains on the electrode or
weld bead indicate contamination
The most common cause is moisture or aspirated air in gas stream. Use welding grade gas only.
Find the source of the contamination and eliminate it promptly
Base metal is oxidised, dirty or oily Use appropriate chemical cleaners, wire brush, or abrasives prior to welding
Inclusion of tungsten or oxides in weld
Cause Solution
Improper lift arc starting technique Follow directions as set out on page 43
Poor scratch starting technique Many codes do not allow scratch starts. Use copper strike plate. Use high frequency arc starter.
Excessive current for tungsten size used Reduce the current or use larger electrode
Accidental contact of electrode with puddle Maintain proper arc length
Accidental contact of electrode to ller rod Maintain a distance between electrode and ller metal
Using excessive electrode extension Reduce the electrode extension to recommended limits
Inadequate shielding or excessive drafts Increase gas ow, shield arc from wind, or use gas lens
Wrong gas Do not use ArO
2
or ArCO
2
GMAW (MIG) gases for TIG welding
Heavy surface oxides not being removed Wire brush and clean the weld joint prior to welding
Porosity in Weld Deposit
Cause Solution
Entrapped impurities, hydrogen, air, nitrogen, water
vapour
Do not weld on wet material. Remove condensation from line with adequate gas pre-ow time
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 the travel speed
Contaminated shield gas Replace the shielding gas
46
BOC Smootharc 180 Multiprocess operating manual