The tungsten electrode is one of the most critical parts of any TIG welding setup. After all, it is the tungsten electrode that transmits the arc from the welder to the metal. If your electrode isn’t set up correctly, you can’t get a clean, strong weld. For the best performance of the welding arc, the electrode is usually sharpened before welding. This process can be confusing for new welders.
So how do you sharpen tungsten for TIG welding? You need to choose a sharpening tool, then follow six simple steps.
- Cut or break off any contamination from touching the electrode to the weld pool
- Use a dedicated, tungsten-only grinder or sander
- Grind parallel to the length of the rod, never across it
- Hold the electrode to the grinder wheel at an angle of 22.5°
- Taper back about 2/3 of the rod diameter and leave a flat spot about 2/3 of the rod diameter on the tip for the best arc
- Wipe it clean with acetone
Choosing the Sharpening Tool
You need to start by selecting a tool to grind your electrode. There are several different tools you can use to perform the grinding. The tools are:
- Specialized tungsten electrode sharpeners
- Bench grinders
- Angle grinders
- Belt or disc sanders
- Chemical electrode sharpeners
Each device has advantages and disadvantages. Whichever tool you choose, you need to follow the six steps listed above to put a clean, fresh point on your electrode.
The Tool for the Job
Ask four welders about the best tool to sharpen tungsten electrodes for TIG welding, and you’ll get five opinions about what to use. The truth is that there are many useful tools for sharpening electrodes. Each one has advantages and disadvantages. Unlike sharpening knives or woodworking tools, tungsten sharpening is a power-tool only business. There are no hand tools that can do this job.
Tungsten Electrode Sharpeners
Many companies make dedicated power grinders for sharpening tungsten electrodes. These tools make a perfect point every time. Since they don’t work for anything but grinding electrodes, the grinder wheel stays clean. The tools are small enough that you can keep them right at the welding bench, so you always have a sharpener handy when you need one. These tools also make getting the right angle a snap.
Tungsten sharpeners come in two flavors: relatively inexpensive hand-held tools and high-dollar industrial models. The less expensive sharpeners usually grind at a fixed angle with no adjustment. While cheaper than industrial sharpeners, these are still a lot more expensive than some other grinding tools.
The industrial-grade tungsten sharpeners allow you a lot more control over the angle and length of the grind, but they are costly. These are best for someone who needs to crank out lots of TIG welds every day and doesn’t have time to walk over to another workbench to sharpen electrodes.
A welder using one of these sharpeners is like a sketch artist having a pencil sharpener at their desk. Any time the tip gets dull, it is a quick and easy action to poke the electrode into the sharpener to refresh the point.
There are also attachments for rotary tools that sharpen electrodes. These are less expensive than the other dedicated sharpeners but still pricey. You also have to have a rotary tool and set it up for sharpening electrodes. If you don’t have the rotary tool, buying one with a sharpener costs about the same as buying a dedicated sharpener.
All of the dedicated sharpeners have slots or holes sized for 1/16 and 3/32 tungsten rods. These slots align the rod with the grinder at the correct angle. Just pop it in, push the button, and grind away. Rotate the electrode slowly back and forth between your fingers to avoid flat spots.
Bench grinders are probably the most common tool used to sharpen electrodes. If you are welding, chances are you already have a bench grinder. (If you are welding and don’t have a bench grinder, you need to get one.) Bench grinders are handy and will sharpen the electrode well.
The drawbacks to bench grinders are contamination and distance. If you use the same grinder wheel for everything, you can contaminate your rod. The wheel will have bits of steel, rust, aluminum, and whatever else you have been grinding stuck to it. These particles can be transmitted to the electrode tip if you are not careful. If the tip is contaminated, you will get gunk in the weld that will weaken it.
You can have some dedicated grinder wheels for tungsten and others for general use, but then you must switch them out between jobs. This is a hassle, but it does work.
Another solution for contamination of bench grinders is to buy a dedicated grinder for electrodes only. You can get a cheap grinder at a tool shop like Harbor Freight or Northern Tool. These aren’t heavy-duty tools to last a lifetime, but how much time do you spend grinding electrodes? A cheap grinder is one easy solution.
If you choose to buy a tungsten-only grinder, choose a different brand than your primary grinder. That makes it easy to remember that (for instance), the orange grinder is only for electrodes, and the black grinder is for everything else.
If you are trying to get a lot of metal welded every day, even taking the time to walk over to the grinder can waste valuable welding time. Stopping the weld, going to the grinder, grinding, walking back to the welder, and aligning the electrode take time. It is difficult to get a lot of metal joined up if you aren’t at the welding bench. A dedicated grinder won’t solve this problem.
Pro tip: put the electrode in a low-power drill while you grind it. Spin the drill at the lowest speed you can get while grinding, and you’ll get a smooth taper with no flat spots. This is the easiest and most consistent way to rotate the electrode and get a good, even taper.
Most metal shops have an angle grinder for removing rust, cleaning up slag, and similar tasks. Angle grinders aren’t ideal for sharpening electrodes. To sharpen an electrode with an angle grinder, you have to hold the grinder with one hand and the electrode with the other. This makes it hard to get a consistent angle since both pieces are in your hands with no stable support.
You are also more likely to contaminate the electrode with an angle grinder because of the wide variety of tasks it gets used for. These tools get pressed into service to shape up all kinds of metal. Who knows what kind of gunk is on an angle grinder wheel? You can have a dedicated wheel for the angle grinder just for tungsten, but then you need to take time to switch wheels between electrodes and other tasks.
An angle grinder should only be used when you don’t have any other choices. If you are welding at someone else’s shop and don’t have access to your usual tools, an angle grinder will put a tip on the electrode. It’s hard to get a consistent angle and a clean grind, but it can be done.
Belt or Disc Sander
Floor-model sanders aren’t as common in metal shops as in wood shops, but some folks have them. Since the sander belt is so much bigger than a grinder wheel, they tend to be less contaminated. Disc sanders are excellent because they usually have a table that you can rest the electrode on to get a more consistent angle.
If you have a floor-model belt or disc sander, it will be fine to put a taper on electrodes. If you don’t have one, don’t go out and buy one to sharpen electrodes. There are better options available.
Don’t use a hand-held belt sander for sharpening electrodes. These have all of the problems you get with angle grinders, plus you have to hold the sander upside down or grind the electrode where you can’t see it. Neither solution works very well.
A chemical electrode sharpener is a paste that reacts with the tungsten to burn away contamination and eats the tip down to a sharp point. To use the chemical sharpener, you crack an arc to get the tip hot, then dip the tip into the chemical. Keep the tip in the chemical until it’s sharp.
Some welders like to dip the tip in and out while the reaction is taking place to keep an eye on the shape. Once the tip is sharp enough, wipe the tip and gas cup clean, and you are ready to weld again.
The drawbacks to chemical sharpener are that it’s messy, and it can be inconsistent. The reaction of the paste to the tungsten fizzes and pops. This can get gunk on your gas cup and electrode. The chemical can also react unevenly with the electrode tip, producing odd angles or flat spots. This can impact the quality of your weld arc.
Chemical sharpeners are a great help when you aren’t in your regular welding shop and don’t have access to a full set of tools. Many welders have a love-hate relationship with the chemical. It does a job other sharpening methods won’t do, but it isn’t as good as the other methods, either.
Steps to Sharpening the Electrode
Once you have chosen a tool to sharpen the electrode, these steps will give you a clean electrode that offers a smooth, steady arc.
1. Cut or Break Off Contamination
If you touch the electrode tip to the weld pool, it will pick up molten metal. This metal won’t just be on the surface of the electrode; some of it will mix with the tungsten rod tip. To remove all the contamination, you need to break or cut off the tip. This is easy to do; tungsten is relatively brittle. Grab it with pliers and break it off.
Some sharpeners have a groove for breaking the tip. If you have such a sharpener, put the rod tip into the breaker channel. Insert it so that all of the contamination is below the breaking point. Now give the electrode a sharp snap to break off the bad portion of the rod.
2. Use a Dedicated Tungsten Grinder
Grinder wheels pick up bits of the metal they are grinding. Aluminum is noted for clogging up grinder wheels, but steel also leaves residue behind. If you grind your electrode on a wheel clogged with another metal, you can add contamination back to the rod. Use a clean wheel.
Pro tip: Make sure to move the rod across the surface of the wheel. Tungsten is harder than the grinder wheel. If you run electrodes down the same strip of the wheel every time, it will wear a groove in the wheel.
3. Grind Parallel to the Rod
It can be tempting to hold the rod perpendicular to the spin of the grinder. This lets the rod rotate naturally in your hand as the wheel spins. However, you shouldn’t do this. It makes groves around the outside of the rod that will cause the arc to wander. It’s hard to get a smooth, straight weld bead if your arc is wandering.
Instead of grinding around the rod, grind along the length of it. The long axis of the rod should be parallel to the motion of the grinder wheel. This will produce straight grooves that channel the arc toward the rod tip. Grinding this way gives a smooth and steady arc.
4. Hold the electrode to the grinder at an Angle of 22.5°
22.5° is the most common angle for grinding electrodes. This angle will work for most situations. If you are grinding without a guide, you can find 22.5° this way:
- Before you touch the rod to the grinder, hold it horizontal, perpendicular to the wheel. This is 90°
- Slant the rod from horizontal halfway to vertical. Halfway between horizontal and vertical is 45°
- Now slant the rod halfway again. It should be three-fourths of the way down from horizontal to vertical, or one-fourth of the way up from vertical. This angle is 22.5°, just right for sharpening the tip of the electrode
You can play with the angle a little bit as you learn to TIG weld. Changing the angle and sharpness of the tip changes the characteristics of the weld bead. You use changes in the angle to help your weld penetrate deeper or work better for thin stock.
A long taper with a sharper tip provides a wide bead with shallow penetration. It also is easy to start and produces a very stable arc. Sharper points work better with low amperage. They tend to have a shorter electrode life as the tiny point breaks down. Sharp points are great for welding very thin metal without burning through or warping.
A short taper with a blunt tip makes a narrow bead with deep penetration. The arc is harder to start and tends to wander more. Blunt tips last longer and work well with high amperage. If you are welding thick metal and need to push the weld deep into the metal, use a more blunt tip.
5. Taper 2/3 of the Rod Diameter
The length of the tapered point should be about 2/3 of the diameter of the rod. It doesn’t need to be a long pointy spike, just a little bit of taper to channel the arc. Leave a flat spot on the tip about 2/3 of the rod diameter.
Like the 22.5° rule, the 2/3 back, 2/3 flat isn’t a hard and fast rule. It is a recommendation that works well in lots of situations. You can adjust the grind based on your situation and what feels comfortable. Sharper points work best for thin metal, blunt points for thick material.
6. Clean with Acetone
Grease and oil are the enemies of good welds. After you grind the tip down, wipe it with acetone. The acetone will remove any contaminants that might have come in contact with the tip.
Some other tips for preparing tungsten electrodes for welding:
- Sharpen several at once. If you have a handful of electrodes ready to go, you can swap out electrodes when one gets contaminated. This means you can keep on welding without as many breaks to sharpen.
- Amperage makes a difference. At very low amperages, you need a precise point to control the small arc. Little things like the angle and the direction of the grind make a difference. If you are using very high amperage, the arc is much more forgiving of these factors.
- Use a round tip for welding aluminum using aluminum. This produces a deeper weld and better scrubbing of the aluminum oxide.
Sharpening tungsten electrodes for welding isn’t a difficult task, and there are lots of tools that can accomplish the task. Just make sure to keep the grinder clean, go parallel to the length of the electrode, and put an even bevel on the tip, and you will have your electrode ready to TIG weld in no time.