Purging TIG Welds, Here's Why & How

What is back purging and why is it critical in motorsport fabrication TIG welding?

Purging is the process of removing the oxygen from the inside of an enclosed part prior to TIG welding. Removing oxygen from inside the part protects the back of the weld from oxidation due to the high heat of TIG welding enhancing the quality of the weld. This, in turn, maintains the corrosion resistance of parent materials, ultimately reducing leak rates and even structural failure risks of your finished work.

It is straightforward to tell the difference between a correctly purged and an unpurged or insufficiently purged weld, and in this lesson you will see examples of both.

Note we are talking about back purging in relation to motorsport fabrication applications and in other industries where you are dealing with much larger diameter pipe and tube etc, what is considered best practice may be different for various reasons.

There has simply never been a better time to purchase your first or upgrade your existing TIG welder. Advances in technology mean that inverters are helping us use TIG welders with higher and higher outputs in the home workshop without the need for 3-phase power or a ton of spare storage room.

This is just one module from a full TIG welding course that is designed to help you learn how to weld at home or help speed up what you are doing at the workplace as you get started. If you want to check out the full course, you can find it here.

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TIME STAMPS:
0:00 - What Is Purging?
0:28 - Why Do We Purge Our Welds?
0:42 - Stainless Example Plan
0:52 - Poor Fit Up, Poor Purging
1:24 - Tack Welding Using Kapton Tape
1:47 - Do You Purge Your Tack Welds?
2:01 - Sealing Your Tube Options
2:18 - Silicone Plugs
2:30 - Masking Tape
2:36 - Argon Filling Tip
2:48 - Purging Bottle Options
3:07 - Gas Flow Rate Rule Of Thumb
3:35 - Not Instant To Fill
4:14 - Position Of Your Weld
4:28 - Spend Some Time Practicing And Inspecting
4:37 - Vent Argon, Don't Pressurise
4:54 - Do You Change Your Technique When Purging?
5:09 - Purged Vs Un-purged Example
5:38 - Do It Once, Do It Right
5:56 - Learn More On TIG Welding And Motorsport Fabrication