How to Set Up and Adjust Mig Welding for the Beginner

Welder Voltage

115 Volt welders: Most machines are between 70-130 amps. The lower-end machines (70-90 amps) will usually weld with flux-core wire only. This is to keep the welders affordable. The top end machines come with a solenoid, ready to weld hard wire or flux-cored wire. The maximum thickness for the lower end welders (70-100 amps) is from 1/16″- 3/32″ using hard wire and gas and up to 3/16″ using flux-cored wire.

Choosing Your Wire

Hard Wire: Your welder must have a gas solenoid to run hard wire. With a Gas Solenoid installed you can run steel, aluminum, or stainless steel.

Flux-Cored Wire: All mig welders will run flux-cored wire. Be sure to change the polarity to DC- when you use this wire. For 115 volt welders you will want to run .030 or .035 wire. For 230 volt welders you can run .045, but you will have to buy 045 drive-roll & liners.

Aluminum: You can run aluminum, but it is more difficult. If a nylon liner is available for your gun, buy one and try to run .035 type 5356 wire. 5356 alloy is harder than 4043 and has less tendency to bird nest (ball up) in front of the drive-roll. Be sure to hold the gun as straight and free from bends as possible.

Choosing your Gas

Use Argon/C02 mix for steel, Use Argon for aluminum, Use Tri Mix for stainless steel. I have been told that you can use argon/co2 with flux-cored wire on 115 volt welders to get the penetration of the flux-cored wire with the clean weld of hard wire, although this is twice as expensive to do!

How to adjust your gas: If you have a slight breeze you can adjust the pressure up until you can weld. (up to 35 cfh) If you have too much of a breeze you will have to block the breeze or switch to flux-cored wsire.

How to adjust drive roll tension: Adjust the tension until the wire is able to put slight pressure against your finger. You do not want too much tension or you will
crush the wire if you are using aluminum or Flux-cored wire. Two settings that are adjustable are the wire feed speed/amperage and the voltage. The amperage will adjust automatically with the wire feed speed. The Voltage (heat) is adjusted with a separate knob. It is recommended that you use the chart that comes on the machine.

Trouble Shooting

Problem: Wire is Feeding Erratically Solution: A) Check Drive Roll Tension. B) Replace Liner In Gun.

Problem: Very Shallow Penetration: Solution: Check Polarity + Hard Wire (gas) – Flux-Cored (no gas)

Problem: Poor quality/discolored Welds: Solution: Make sure that you have proper gas flow (min 15 psi

Problem: Wire is too cold, pushing on material w/out melting: Solution: decrease wire feed speed or increase voltage.

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