TIG Welding in the Home Shop

This guide covers a simple TIG welding setup in the home shop. It covers the basic tools you'll need to get started as well as a simple welding cart build.

What is TIG welding?

First, a quick overview on TIG welding. TIG stands for "Tungsten Inert Gas" Welding. Like the name says, the key elements are a Tungsten alloy rod and an intert gas (usually Argon, though Helium is also used). The following diagram shows the TIG welding process by Wikipedia user Duk.

That may sound complicated, but the welding process is actually quite straightforward. The TIG torch is used to heat the metal being welded until a puddle of molten metal is formed. Filler is then added and the torch is moved forward and the process repeated.

Once a proper weld is formed, it should melt and join the metal all the way through the work piece. It can then be sanded or ground down to produce a finished surface. Even my not-so-great looking first weld can be cleaned up nicely using a flappy disk:

Thanks

Thank you to CK worldwide for sending me a couple air cooled, flex-head torches. These are a big upgrade from the torch included with the Lotos TIG200

The smaller CK9 is good up to 125 amps and the standard-sized CK17 up to 150 amps.

The collet and gas cup from the torch included with the TIG200 welder will fit on the CK17. For the CK9, you'll need to get a different collet and gas cup. However, I suggest you get a gas lens setup for the CK17 and the CK9, which will give better gas coverage.

Not only is the CK torch smaller, but it also has a "superflex cable." The combination of these make the CK torch much easier to handle.

The CK9 and CK17 are both flex-heads, which means they can be adjusted up to 40 degrees in any direction to reach into those hard-to-get places.

Just be sure to buy a kit with a superflex cable that has an M16x1.5 thread, which will fit on the Lotos TIG 200.

Both the CK9 and CK17 heads have the same size fitting, so you can easily swap the superflex cable between the two heads.

Tools

Let's talk about the tools we need to get started.

  • Lotos TIG200: I chose this welder since it was the most cost effective machine that could do both DC and AC (for aluminum) welding.

  • Tungsten Electrodes - 3/32 lanthanated 2%: You'll need some Tungsten electrodes. The Lotos TIG200 comes with one red, thoriated tungsten eletrode. However, the thorium oxide in these electrodes is radioactive and potentially dangerous if inhaled or ingested (e.g. while grinding the electrode). Thoriated tungsten also does not work on aluminum. It is better to use either (blue) lanthanated or (purple) rare earth electrodes which will work on both aluminum and steel as well as perhaps be a bit safer.

  • Goatskin TIG Gloves: Though TIG welding does not produce much sparking, a good pair of gloves will protect your hands from heat as well as some inadvertent electrical shock. Goatskin gloves provide a nice balance between protection and dexterity.

  • Welding Helmet: A welding helmet is crucial to protect your eyes from the bright arc and allow you to see what you're welding. There are two main choices: an auto dimming helmet or a manual helmet. An automatic dimming helmet will let you see through the lens when not welding and automatically dim to a safe level when an arc is struck. The manufacturer claims a 1/10000 second response time, and the sensitivity can be adjusted. A manual, flip up helmet is always dark, so to see before starting a weld, you need to move the helmet up and get positioned. Once ready, you flip down the lens and then start welding. I learned to weld on a manual helmet, but an auto dimming helmet is much more convenient.

  • Argon Tank with CGA 580 Valve: A crucial part of the TIG process is the inert gas. I found ordering an argon tank online was cheaper than purchasing one from a local supplier, but your luck may vary. Just be sure to buy one with a CGA 580 valve and it can be filled (they actually swap them) at your local welding store.

  • Rotary Tool: Your tungsten electrode will need to be sharpened periodically and cleaned when it accidentally comes in contact with the base metal. Any abrasive device can be used for this, such as a bench grinder, belt sander, or a cutoff wheel, but you want to make sure to not use this for any other work, as to not contaminate your electrodes. I find having a dedicated rotary tool with a diamond coated rotary disk is the most convenient option. While you can just free-hand hold the rotary tool and the electrode, having a guide makes this much easier. I used my 3D printer to make this electrode grinding attachment, but they are also available on amazon.

  • Angle Grinder, Flap Disks, and some Cutoff Wheels: An angle grinder is the cheapest and easiest way to cut material, clean surfaces before welding, and clean up after welding.

Setup

The first thing you'll need for your welder is a 240v outlet with a NEMA 6-50R receptacle. If you don't have one, you'll need to have one installed.

Your tank will come with a large cap over the valve, to protect it during shipping. Remove this cap and attach the regulator included with the Lotos TIG200. Don't use any teflon tape as small pieces could come free and enter the gas system, potentially clogging a valve. The fittings are brass, which seals on brass, so just tighten each fitting down as tight as you can. Don't add teflon tape. Connect the included hose between the regulator and the welder.

Before you assemble your torch, sharpen your tungsten. I'm using my rotary tool and 3d printed grinding attachment.

Then, setup your torch. You'll need a collet holder, collet, gas cup, sharpened tungsten, and torch back. I used those included with the Lotos TIG200 torch, but a gas lens setup would save a bit of gas and provide better coverage.

Next, connect all the elements of the front panel of your welder. From left to right, these are the welding torch (remove the yellow cap), skip the stick welding port, the pedal switch cable and the pedal voltage regulator cable, and finally the included clamp.

Now, turn the welder on with the switch in the back and turn the regulator all the way down, then open the valve on the argon tank.

Press the pedal to start the flow of gas and check the flow rate, adjusting the regulator and checking until proper flow is achieved. Bigger cups will need more gas, but with a size 6 cup, I found a flow rate of about 15 cubic feet per hour (cfh) works well.

The welding cart

To practice with the new welder, I decided to build a welding cart. I designed a cart that can hold both the welder and a water cooler. Here is a simple sketch:

I am using 0.625" x 0.065" Hot Rolled Carbon Steel Square Tube from Online Metals. You'll need about 350 inches of tubing, cut into the following lengths:

QuantityLength
4x4"
5x12.5"
4x22"
2x25"
4x32"

Use a cut-length calculator, like optiCutter to figure out what lengths of stock steel to order given the shipping costs.

I cut the stock down to length using my band saw, but it could just as easily have been done on the grinder with a cutoff wheel.

You'll also need 4 swivel casters, some length of chain to secure the tank, and a plate for the bottom. I used a 12.5"x32"x1/8" plate that I cut down from a longer piece using the cutoff wheel on the grinder.

Use your grinder with a flap disk to clean the surfaces you will weld.

Weld the sides of the cart together. Place something heavy on the parts or clamp them to your table. Tack and weld each joint. I'm not putting the angled, ~25" bars along the top yet. I'll add these later when I get a water cooler.

Then position and weld the sides together.

Prep the casters, removing any paint or plating where you'll weld. Weld on the casters.

I built a support for the tank.

Finally, I welded on a chain to one side of the tank support and an open loop of chain to the other, securing the tank in place.