M I G – M A G Welding Systems

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Problem Solving & Maintenance on M.I.G.–M.A.G. Welding Systems

As with all welding processes, the correct setup and maintenance of the welding equipment is vitally important to ensure continuous automatic feeding and successful weld deposits.

1. It is advisable to blow out the interior of the machine with DRY compressed air or cleaning with a brush on a regular planned maintenance program. This will ensure that any metal containing dust, drawn in the machine by the cooling fan and deposited onto the components, do not cause unnecessary heat build up (reducing the duty cycle) or possible short circuiting of the vital components.
    
2. When fitting the reel of wire, ensure that it is properly located onto the hub and that the hub tightening screw allows for free movement of the wire reel.
    
3. Ensure that the guide tubes and rollers are clean and that the correct roller and liner is being used for the size of wire being fed.
    
4. The tightening of the rollers onto the wire should be just enough to feed the wire through the torch. Over-tightening of the rollers may cause the copper coating on the wire to be abraded and copper particles may be fed into the liner causing clogging and bad feeding conditions.
    
5. Keeping the torch cable as straight as possible ensures smooth feeding. Each bend in the torch cable causes the wire being fed through the liner to rub against the liner surface and damage or deposit dirt, with the resultant bad feeding of the wire.
    
6. Whenever practical, suspend the torch cable off the floor by using suspension reels or floor stands. This will improve feeding (straightness of cable), save the cable from being damaged from sparks, spatter, slag, being walked or driven over, heavy objects falling onto it and most important, will reduce the weight loading of torch head and cable on the wrist of the operator, thereby improving his efficiency.
    
7. When welding non-ferrous metals i.e. Aluminium, Copper or Nickel alloys it is highly recommended to use a separate torch specifically for use on these metals, fitted with the correct Teflon liner and feed rolls and that the torch cable length is as short as possible and kept straight.
    
8. Regular cleaning of the liner by either blowing out the liner channel with DRY compressed air or removing the liner, inspecting the condition, replace if damaged or washing with water, drying and replacing will ensure smooth feeding of the wire.
    
9. When welding long continuous welds or on heavy sections with high current the contact tip hole (size dependant on size of wire being fed) may reduce in size and crimp onto the wire causing irregular feeding. Using one size larger contact tip than the wire diameter will overcome this problem. The wire picks up the current from the contact tip and by using too large a contact tip may influence weld deposit quality and arc control. Contact tips are inexpensive and should be replaced regularly.
    
10. Porosity on and in the welds are mostly as a result of insufficient gas shrouding of the weld pool and base metal surface impurities. Ensure that the nozzle (shroud) is free of spatter as the flow of shrouding gas may become volatile and not provide adequate shrouding of the weld pool. Ensure that when spraying or dipping the nozzle with Anti-Spatter silicon spray or jell, that the diffuser does not get clogged and cause inadequate weld pool gas shrouding.
     
11. It is highly recommended that a qualified electrician connects the input power cables to the welding machine. This will ensure that the correct phasing and earth is obtained for the correct operation and safety use of the welding machine.
     
12. Ensure that the correct output connection for earth (workpiece) is done and that the wire feeder (separate wire feeder) is connected to the wire feeder.
     

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