Drive Welder

Do you need to prime the shielding gas line in a MIG welder before use?

I’m new to welding, and recently purchased a Hobart 187. I have an argon CO2 tank hooked up to the welder. When I squeeze the trigger on the gun, a valve opens by the wire drive wheels and allows the shielding gas to travel down the hose and out the tip. My questions are this:

When my welder has been sitting unused for a few days and I go to start welding something, do I need to purge the atmospheric air that is in the line between the tip and the valve that’s by the drive wheel?

What I have been doing is disengaging the drive wheel and squeezing the trigger for a few seconds to start a flow of pure shielding gas. Then I engage the wheel and begin welding.

Is this the right thing to do, or can I just turn the machine on anytime and start welding (after turning on the gas at the main tank)?

The gas will be at the tip in less than a couple seconds. Unless you are welding something that it really matters for quality the then I would just turn it on make adjustments and weld. On most tanks you have a regulator and you should set the regulator each time you start up. If it is a flow meter type you have to set it while flowing gas (trigger pulled). On the pressure type (like the oxy/acetylene type) you need to set the pressure each time you open the valve (if you are not then you are not treating your regulator correctly as each time you turn the tank off you should release the pressure in the line and back the adjuster off to protect your regulator for the high pressure shock of the next time you turn the tank on.

(30+ years welding- certified)

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