TIG welding stainless steel can be challenging, requiring a combination of skill, knowledge, and practice. Whether you’re new or an experienced welder, there’s always room to improve.
So, I’ve put together a collection of helpful tips and tricks to help you achieve better results and produce satisfying results. From choosing the right rods to adjusting your settings and maintaining a clean workpiece, our TIG welding tips for stainless steel are designed to help you succeed and make your fellow welders envy you.
9 Steps to TIG Weld Stainless Steel
1: Cleaning the Stainless Steel
Clean the workpiece to make sure it’s free of contaminants. Even the tiniest speck of dirt, grease, or oil can significantly impact the weld quality, resulting in weak or brittle joints prone to cracking and corrosion.
Start by thoroughly scrubbing it with a wire brush to remove any contaminants. Additionally, use a degreaser for more satisfaction. Follow the manufacturer’s instructions carefully and use the appropriate safety gear to protect yourself from harmful chemicals.
Once you’ve cleaned your metal, keeping it free from contamination during the welding process is essential. So, avoid touching the metal with your hands to avoid transferring oils and sweat that can interfere with the welding process. Instead, use clean gloves or a clamp to hold the metal.
Also, it’s important to ensure that you use clean filler rods and welding wire. Any contamination of these materials can also affect the quality of your welds, so be sure to store them in a clean, dry place and handle them with care.
2: Selecting the Right Tungsten Electrode
Several types of tungsten electrodes are available in the market, each with distinctive properties. Thoriated and ceriated tungsten is commonly used for most welding applications. Both are easy to start and offer good arc stability. However, due to potential health risks associated with thoriated electrodes, most welders prefer to use ceriated rods as they don’t contain radioactive materials.
The type of tungsten rod doesn’t affect the weld quality; you only need to make sure the use the correct size for your application. For example, if you try to weld thin sheet metals at low amperage using a bigger diameter tungsten electrode, you will surely end with an inconsistent weld. As a general rule, rod diameter and metal gauge are directly proportional. For instance, the heavier the gauge, the more the diameter of the rod.
See the chart to help you select the right rod diameter according to the metal thickness and the amperage range.
|Material Thickness||Electrode Diameter||Recommended Electrode Size|
|0 – 1/16 inch||1/16 inch||1/16 inch|
|1/16 – 1/8 inch||3/32 inch||3/32 inch|
|1/8 – 1/4 inch||1/8 inch||1/8 inch|
|1/4 – 1/2 inch||5/32 inch||5/32 inch|
|1/2 – 3/4 inch||3/16 inch||3/16 inch|
|3/4 – 1 inch||1/4 inch||1/4 inch|
3: Make Electrode Tip Contaminants Free
The electrode tip can become contaminated over time, which can cause arc instability leading to uneven weld beads. In contrast, a clean, sharp electrode tip can help produce a consistent weld bead and improve the overall quality of your work.
Inspect it thoroughly and ensure it’s clean and sharp before starting welding. If it looks dull, contaminated, or damaged, consider replacing it with a new one. However, you can also use a small, fine-grit sandpaper or a sharpening stone to sharpen the tip and remove any contamination gently.
4: Use a Larger Cup for Gas Coverage
Ensure your welds are free from oxidation and contamination by providing proper gas coverage. One way to achieve this is by using a larger gas cup or nozzle, which provides a wider and more consistent coverage area while minimizing turbulence in the gas flow.
Another option is to use a trailing shield or back purge device that delivers additional gas flow to the backside of the weld. Finally, make sure to position your gas cup or nozzle correctly, as close to the weld as possible, without touching it, to ensure optimal gas coverage.
Don’t forget to check your welder’s manual or consult a professional to determine the appropriate gas flow rate for your specific application.
5: Reduce Heat in Concentrated Areas
It’s crucial to control the heat input to avoid distortion, warping, and cracking in the metal. One way to do this is by increasing your welding speed, which reduces the time the heat is concentrated on any metal area.
However, balance speed with gas coverage and weld penetration to produce a high-quality weld. To increase your welding speed, practice on scrap metal pieces to find the right balance between speed, gas coverage, and penetration. Then, adjust your technique to move quickly and evenly across the metal’s surface while maintaining a consistent distance between the torch and the workpiece.
In addition to increasing your speed, you can preheat the metal, use a lower amperage setting, or pulse welding to control heat input.
Also Read: Best TIG Welders
6: Selecting the Right Filler Rod
Choosing the right filler wire is crucial for producing strong and durable TIG welds on stainless steel. You want to ensure that the filler wire is compatible with the grade of stainless steel you’re using and consider its diameter, composition, and level of contamination.
Thinner filler wire can provide more precision, while thicker filler wire can be easier to work with. The composition of the filler wire can affect its resistance to corrosion and high temperatures. To ensure you’re using the right filler wire, consult a welding expert or refer to the manufacturer’s recommendations. See the chart below to have better knowledge of filler rod sizes.
|AWS Classification||Filler Material||Suitable for Welding|
|ER308||308L, 308LSi||304, 304L, 321|
|ER309||309L, 309LSi||309, 309L, 347|
|ER316||316L, 316LSi||316, 316L, 318|
|ER2209||2209||Duplex Stainless Steel|
7: Back Purging
When welding stainless steel pipes or tubes, it’s important to pay attention to the quality of the weld, both inside and out. This is because the inside of the joint can be difficult to access after completing welding, making it harder to fix any issues. Back purging is a key step in the welding process to prevent problems.
This involves introducing an inert gas like argon into the pipe’s interior or tube while welding on the outside. The gas flow displaces the air inside the joint to prevent oxidation and contamination. There are different methods for back purging, but the important thing is to monitor the flow rate and ensure proper interior protection throughout the welding process. With the right techniques, back purging can help you achieve high-quality, corrosion-resistant welds inside and out.
8: Choose the Current Polarity
You should generally use direct current (DC) with the electrode negative (DCEN) polarity. When using DCEN, you will connect the positive terminal to the workpiece and the negative to the power source. Besides, it also minimizes the risk of warping as it prevents excessive heat buildup around the workpiece, improving weld penetration and creating stronger welds.
However, some stainless steel types, such as duplex, may require a different polarity setting. So, I recommend you consult with a welding expert or refer to the manufacturer’s recommendations to ensure that you use the correct polarity for your specific application.
9: Avoid Heating in One Spot
Excess heat can cause discoloration and even weaken the weld. However, the right technique can achieve a beautifully welded joint without unsightly discoloration. The key is to avoid keeping the arc in one spot for too long and to take breaks when the metal gets too hot.
Doing this can prevent discoloration and deformation from ruining your project while ensuring that your weld has good penetration and is strong and long-lasting.
What is the best amperage for TIG welding stainless steel?
The amperage ranges from 70 to 90 is used in most cases. However, it also depends on the thickness of the stainless steel piece that is being welded.
Finally, I hope these tips and tricks for TIG welding stainless steel will help you improve your welds’ quality and durability. Remember to choose the right filler wire, back purge your job, let your project cool, and use proper technique when welding.
In addition to these tips, it’s important to remember that TIG welding stainless steel is a skill that takes practice and patience to master. Don’t be discouraged if your welds don’t turn out perfect immediately – keep practicing and seeking new tips and techniques to improve your skills.
Read Also :
- TIG Welding Tips for Beginners
- Learn to TIG Weld Aluminum
- Pros and Cons of TIG Welding
- Best Welders for Steel Exhaust Pipes