Converting my Lincoln Weldpak 100 Wire-Feed Welder to MIG

I don't remember when I bought my Lincoln wire feed welder but it was many years ago, and I bought it used. For all these years I've had it, it's been a nice upgrade from my 45-year-old Sears Craftsman buzz box stick welder.

As nice as my wire-feed welder is, it has come time to upgrade it to MIG. I've had the idea to do the update for many years but finally decided to bite the bullet. There are many videos online on how to purchase the parts necessary, or you can just buy the Lincoln kit for $188 at Home Depot. I was able to purchase the parts for $60. The HD kit comes with a .025/.030 liner and a 2lb roll of welding wire, so it has a couple more things than what I bought, but I intend to buy a 10lb roll of .030 wire, and I'm not swapping out the .035 liner in my welder, as I heard I can use my liner with .030 wire. I also got 10 .030 tips and two nozzles, whereas the HD kit only comes with two tips and one nozzle. All in all, I think it's a lot better choice to buy the parts individually.

Here are the parts I bought:

What I got:
- Ten .030 tips
- Two 1/2 inch MIG nozzles
- 120v gas solenoid
- two hose barbs
- Argon gas regulator
- Ten feet of 1/4 inch vinyl tubing

Prior to doing this update, I needed to make sure my welder had the necessary items already installed. They are a gas nipple at the wire feed mechanism and terminals on the main electronics board for the gas solenoid. Mine had them both.

So on to the update. First thing was to install the solenoid. The welder already had a hole out the back of the machine and screw-mount holes so I didn't need to do any drilling to install the solenoid.

The black plug below the screw is where the solenoid nipple will be.

There are two oblong holes to mount the solenoid.

Only one screw hole lined up with my Chinese solenoid but it will work fine.

The next photo shows the solenoid valve installed.

The two solenoid wires plug into the electronic board, just above the solenoid.

I ran the vinyl tubing from the solenoid valve to the wire-feed drive nipple. I had to use a hose clamp since the factory nipple was smaller than the stuff I purchased.

And as you'll note in the above photo, the "+" terminal goes to the wire-feed block and the "-" terminal goes to the ground lead. When welding with gas, the polarity needs to be reversed from what is used in flux-cored wire-feed welding. Wire-feed has the wire-feed block at negative polarity.

Now for the simple matter of swapping out the .035 tip and wire-feed nozzle for the .030 tip and MIG nozzle.

My welder's gun is called a Magnum 100L, so it was just a matter of finding the right parts to fit the gun. I purchased the gun tips, solenoid valve, and gas regulator on eBay.

The next step is to buy a bottle of Argon/CO2 mix and some MIG wire. That doesn't sound cheap...