Mig (Gmaw/Fcaw) Welding Troubleshooting - ESAB Fabricator 181i Operating Manual

4.02 MIG (GMAW/FCAW) Welding Troubleshooting

Solving Problems Beyond the Welding Terminals
The general approach to fix Gas Metal Arc Welding (GMAW) problems is to start at the wire spool then work through to the MIG
Gun. There are two main areas where problems occur with MIG, Porosity and Inconsistent wire feed
Solving Problems Beyond the Welding Terminals - Porosity
When there is a gas problem the result is usually porosity within the weld metal. Porosity always stems from some contaminant
within the molten weld pool which is in the process of escaping during solidification of the molten metal. Contaminants range from
no gas around the welding arc to dirt on the work piece surface. Porosity can be reduced by checking the following points.
FAULT
1 Limited or no shielding gas flows
out of the MIG Gun nozzle.
Shielding gas cylinder contents
2
and flow gauge.
3 Gas leaks.
4 Internal gas hose in the Power
Source.
Welding in a windy environment.
5
6 Welding dirty, oily, painted,
oxidized or greasy plate.
7 Distance between the MIG Gun
nozzle and the work piece.
8 Maintain the MIG Gun in good
working order.
Manual 0-5421
Check that the MIG Gun connection is fully engaged into the MIG
Gun Adapter. The o-rings in the MIG Gun connection must seal
the shielding gas within the MIG Gun Adapter so the shielding gas
flows into the MIG Gun and out thru the MIG Gun nozzle.
Ensure that the shielding gas cylinder is not empty and the flow
meter is correctly adjusted to workshop welding: 28-35 CFH or
outdoors welding: 35-46 CFH.
Check for gas leaks between the regulator/cylinder connection and
in the gas hose to the Power Source.
Ensure the hose from the solenoid valve to the MIG Gun adaptor
has not fractured and that it is connected to the MIG Gun adaptor.
Shield the weld area from the wind or increase the gas flow.
Clean contaminates off the work piece.
Keep the distance between the MIG Gun nozzle and the work piece
to a minimum. Refer to section 2.03
A Ensure that the gas holes are not blocked and gas is exiting out of
the MIG Gun nozzle.
B Do not restrict gas flow by allowing spatter to build up inside the
MIG Gun nozzle.
C Check that the MIG Gun O-rings are not damaged.
Table 4-2: Solving Problems beyond the Welding Terminals-Porosity
ESAB FABRICATOR 181i
CAUSE
4-5 BASIC WELDING GUIDE