If you are new to TIG welding, you will stumble upon a piece of equipment called a foot pedal. This will initially puzzle you because it’s hard to figure out why you may need something handled by your foot since your hands do the welding.
In this article, you will learn what a foot pedal is, how it works, how to select one, and how to maintain it.
Table of Contents
- What is a TIG welding foot pedal?
- How does a TIG foot pedal work?
- Is a foot pedal necessary to TIG weld?
- Alternatives to the foot pedal
- How to set up and use a TIG foot pedal
- Useful tricks
- How to select a TIG foot pedal
- How to maintain your foot pedal
What is a TIG welding foot pedal?
A TIG welding foot pedal is an optional remote control device you use with your foot to start and stop the arc, but also control the amperage dynamically while you weld. This way, you control the puddle’s heat without stopping to readjust the amperage or by using controls on the TIG torch.
TIG welding is famous for its high efficiency for hard-to-weld metals and joints. It’s also famous for how hard it is to learn. A foot pedal adds higher control, but also more complexity for a beginner.
Parts of foot pedals
A typical TIG foot pedal consists of four main parts: the body, the potentiometer, the cord, and the plug.
- The main body houses and protects the potentiometer, the spring, wires, and other components. It’s made from durable plastic or steel and is recommended to be water, dust, and heat resistant. The bottom side has non-slip traction pads to keep it in place. The top side also provides a stable grip for your foot.
- The potentiometer is the device that precisely controls the welding circuit. It’s connected to the pedal’s moving parts.
- The cord usually between 15-25′ allows the signal transfer between the pedal and the TIG machine.
- The plug connects the cord to the machine’s control connector.
Types of foot pedals
There are two types of TIG foot pedals: wired and wireless.
The wired ones are the most popular. Their signal is always reliable and they are the cheaper option. However, the wire can be burned or cut, adds to the clutter, and is a tripping hazard.
Wireless pedals come with a small receiver unit that plugs into the machine. They have a battery that powers a transmitter that sends the signal to the receiver. This way, you avoid the wire problems.
However, they are much more expensive and useful only for specific professional environments where a wire is too much trouble.
Also, the line of sight between the receiver and the pedal should be clear and within a specific distance. This way, the signal stays reliable to keep the arc stable.
How does a TIG foot pedal work?
When you press the pedal, the gas pre-flow starts, after that current flows and the arc starts. If you have a water-cooled torch, the pedal also starts the water flow.
As you weld, you press the pedal to increase the amperage or depress it to lower the amperage. This way, you control the heat input without changing the welding speed or the arc length.
When you completely depress the pedal, the arc stops and the gas post-flow starts to protect the hot tungsten and the bead until they cool down.
- You avoid controlling the amperage with controls on the torch. This way, you increase the torch stability and reduce hand fatigue.
- You avoid interrupting your work to correct the amperage, which greatly increases your productivity.
- Dynamically adjusting the amperage allows you to weld joints with uneven fitup. You increase the heat to melt thicker parts or narrow open-root joints. You decrease the heat to avoid burning through thinner parts or wide roots.
- Since you control the amperage on the fly, you can get higher-quality beads both in strength and appearance.
- With a foot pedal, you can avoid or lower the cost, time, and trouble of preheating.
- You can manipulate the heat input when you reach the joint’s end to fill the crater with enough filler metal. This way, you avoid crater cracks and create a good-looking crater.
- Adding another piece of equipment adds to the difficulty. You need a lot of practice to learn when and how much you should press or depress the pedal. You also need to keep the foot pressure steady to keep the arc stable.
- If your TIG machine didn’t come with a pedal, buying one is not cheap. An affordable one may cost $200, but a quality one may start from $600. It’s also costly if you repair it.
- A pedal creates clutter and is a tripping hazard that can result in injuries.
Is a foot pedal necessary to TIG weld?
A foot pedal is not necessary to TIG weld. However, it’s helpful for very thin metals and many hard-to-weld metals such as aluminum, stainless steel, cromoly, etc.
Welding thick aluminum is the most common scenario you want to use a pedal. Aluminum absorbs and stores the welding heat at high rates.
When you start welding, you want a high amperage arc for a few seconds on the cold aluminum to quickly form the puddle.
After that, you slightly depress the pedal to lower the amperage and start welding.
However, as you weld, the remaining joint gets too hot. This is when you want to continuously lower the amperage to avoid getting an ugly bead, warping, or a burn through at the joint’s end.
Before you stop the arc, you use the pedal to further decrease the amperage to fill the crater with enough filler metal. You do that to avoid crater cracking because aluminum shrinks a lot.
If you weld mild steel, a pedal is helpful only if you weld thin sheet metal, let’s say thinner than 1/8″ (3.2 mm).
Alternatives to the foot pedal
The alternative to a foot pedal is a TIG torch that comes with a variable amperage control. You can also attach a control to your existing torch.
The control plugs into the control connector just like a pedal. The advantage is the lower cost and that you don’t have to reposition the pedal if the workpiece is large.
This option, however, doesn’t offer the same results. Manipulating the control reduces your hand’s stability, and the added weight fatigues your hand faster.
How to set up and use a TIG foot pedal
Setting up a pedal is easy, using it needs some practice, but after that, you probably won’t weld demanding jobs without it:
- Connect the pedal’s plug to the control connector that’s in the front panel of your TIG machine.
- You use your normal tungsten, cup size, gas flow rate, etc., for the job.
- Turn on the machine and set the amperage you want to weld. As a general rule, set one ampere per thousand of an inch (or 40 amperes per millimeter) of the workpiece thickness. For example, if you have a workpiece .125″ (1/8″, 3.2 mm) thick you set 125A.
- Keep in mind that you don’t select the 4t mode with a pedal, but only the 2t mode. That also means that you don’t need the upslope and downslope so set them to zero.
- An optional step, depending on your machine, is selecting the remote mode with the proper control or pressing the pedal for a few seconds.
- Point the torch on the workpiece and press the pedal to start the gas flow and the arc. With the proper amperage, you should see the puddle form in less than 3 seconds. Then, add filler metal, and start welding.
- As you weld, you can press the pedal to increase or depress it to decrease the amperage. As a general rule, you depress it slightly as you weld, because the joint becomes hotter and hotter.
- When you reach the joint’s end, you depress the pedal and add filler metal to fill the crater.
- Finally, step off the pedal to stop the arc and start the gas post flow.
If your Welder doesn’t have the capability of pulsed welding, you can use the pedal to emulate it:
- Set the amperage 10% higher than normal.
- Let the cup touch the joint and keep a short arc length. That’s the distance between the tungsten electrode and the metal.
- Press the pedal all the way down to release the full amperage.
- Add filler metal and depress the pedal about 3/4″ (19 mm) then move the torch ahead.
- Repeat steps 3 and 4 until you fill the joint.
By using this trick, you can have around one pulse per second.
You shouldn’t use this pulse trick on demanding welds because you cannot have the perfect timing that a pulsed machine offers. You will not have the same quality results.
If you have a joint with a symmetrical fitup and without a root gap, you can increase the efficiency of your tack welding:
- Set the amperage to 50% up to 100% higher than normal.
- Position the tungsten for a tack weld.
- Press the pedal all the way down for no more than a second and completely release it to create a small-sized tack weld.
- Repeat to create all your tack welds.
Keep in mind that this high-amperage tacking without filler metal may harden high-carbon steel, resulting in a cracked tack weld. The same can happen if you weld aluminum because it’s soft, it shrinks a lot, and many alloys need a specific filler metal type to avoid cracking.
How to select a TIG foot pedal
First, TIG foot pedals are not universally interchangeable. You must select a compatible one for your machine.
The easiest thing to do is to check the manual or the manufacturer’s internet site for the pedals your machine supports.
If you want to do it on your own, let’s see what you should consider:
- While many TIG machines support foot pedals, you should check if yours has the required control plug. If it doesn’t, you cannot use a pedal.
- Check how many pins the connector has. Keep in mind that there are adapters to connect pedals with more or fewer pins.
- It would be best if you can test some pedals to feel how smooth or rough they are, how much pressure they need to press them, and if it fits your shoe size. Personal preference and comfort are essential when you choose any kind of equipment.
- Make a visual inspection. If there are open gaps between the pedal and the body, avoid it. Dirt will enter the body and eventually damage it.
Tip 1: The affordable model of your welding machine manufacturer is probably your best choice.
Tip 2: Be careful when you do your research to avoid buying a simple foot switch that only starts and stops the arc without controlling the amperage like a proper pedal.
How to maintain your foot pedal
Maintaining your foot pedal will expand its service life and keep its smooth operation and responsiveness:
- After you finish your work, check the cord to see if it’s burned or cut to avoid exposed electrical wires.
- Then use a clean cloth to remove dust, spatter, and any other dirt that settled on the pedal.
- Once in a while, lubricate the moving parts to prevent uneven amperage flow.
- Occasionally, you can check the potentiometer with a multimeter to see if it works properly.
Keep your pedal stored in a cabinet if you don’t use it. There is no need for it to be exposed to the workshop’s hazards or to occupy space if you will not use it.
A foot pedal is an optional but important addition to TIG welding, especially for aluminum.
By controlling the welding heat while you weld, you improve the final bead and increase your productivity.
If you are a beginner or you weld at home, you don’t need an expensive pedal.
However, if you want to weld with commercial intent you should get a quality pedal, most often the one recommended by your welding machine manufacturer.