beautypg.com

02 mig (gmaw/fcaw) welding troubleshooting – Tweco 550i Transmig User Manual

Page 51

background image

TRANSMIG 350i, 450i, 550i

Manual 0-5205

4-7

BASIC WELDING GUIDE

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 torch. There are two main areas where problems occur with GMAW, 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

CAUSE

1 Shielding gas cylinder contents

and flow meter.

Ensure that the shielding gas cylinder is not empty and the

flow meter is correctly adjusted to 15 litres per minute.

2 Gas leaks.

Check for gas leaks between the regulator/cylinder connec-

tion and in the gas hose to the Power Source.

3 Internal gas hose in the Power

Source.

Ensure the hose from the solenoid valve to the torch adaptor

has not fractured and that it is connected to the torch adaptor.

4 Welding in a windy environment.

Shield the weld area from the wind or increase the gas flow.

5 Welding dirty, oily, painted,

oxidised or greasy plate.

Clean contaminates off the work piece.

6 Distance between the MIG torch

nozzle and the work piece.

Keep the distance between the MIG torch nozzle and the work

piece to a minimum. Refer to section 2.03

7 Maintain the MIG torch in good

working order.

A Ensure that the gas holes are not blocked and gas is exiting

out of the torch nozzle.

B Do not restrict gas flow by allowing spatter to build up inside

the torch nozzle.

C Check that the MIG torch O-rings are not damaged.

Table 4-1: Solving Problems beyond the Welding Terminals-Porosity

!

WARNING

Disengage the feed roll when testing for gas flow by ear.

This manual is related to the following products: