How To Weld 20 Gauge Sheet Metal

When I’m not working in the garden, you can usually find me carrying out property repairs. 

It’s just that my husband and I have made the house from scratch, so you can understand the emotional attachment that comes with it. Naturally, I support my husband in repairing any issue that may crop up. 

Now, you may worry about the state of the property but let me assure you that it’s well-maintained. Since I was a kid, I have been working on DIY tasks, and I’m pretty handy with a welding wire or power saw. 

Understandably, when the roof started deteriorating, I went to the store to pick up essential supplies for the project. The manager suggested that I use 20 gauge sheet metal to reinforce the roofing, but little did I know what was in-store. 

As I started welding, the wire burned through the surface and warped the metal, much to my horror. I realized something was wrong, and a quick internet search confirmed that welding sheet metal is different from other materials. 

So, today I’m going to tell you how to weld 20 gauge sheet metal without any difficulty. Hi! I’m Stacy Smith, and let’s get started. 

Welding Sheet Metal

What Is Sheet Metal?

Compared to other substances, sheet metal is thinner, making it suitable for roofing projects, vehicles, airplane wings, medicine tables, and fuselages. It is also available in several materials like steel, aluminum, stainless, and galvanized steel. 

Now, to determine the strength of the material, you need to look at the gauge value. Usually, the gauge range varies from 7 to 30, with a lower value equivalent to a much stronger metal. 

Understandably, my 20 gauge sheet metal wasn’t the strongest. But I found that the following techniques come in handy when dealing with thin materials. 

1. MIG Welding

MIG welding is one of the best ways to use 20 gauge sheet metal because the technique is extremely easy to master. When I was new to welding, my dad introduced me to this method that involves adding a solid wire electrode to a welding gun. 

You’ll also find that it comes with an inert gas that shields the metal surface from impurities, thereby delivering precise results. In fact, it is possible to alter the gas content by using 95% argon and 5% carbon dioxide, depending upon the type of task. 

Once you have a suitable material and the necessary shielding gas, operating on metals ranging from ½ to 24 gauge thickness becomes convenient.

Now, as a DIYer, I have picked up on certain tips to get the desired output. For instance, in this technique, it would be best to ensure that the filler metal is thicker than the base metal. 

Hence, you will be able to use a 0.30-inch wire to pierce the surface and join the material. 

2. Gas Tungsten Arc Welding

If you need high-quality output, considering it’s a small-scale task, choosing the gas tungsten arc welding method may prove useful. It worked well for me as it doesn’t affect the quality of the material. 

But especially pleasing is the fact that it doesn’t produce much spatter, making it worth the investment. However, you must note that it takes time to get accustomed to this technique as it’s not particularly simple. 

I had to practice several times to grasp the method since I had never worked with tungsten electrodes measuring 3/32 inches. Moreover, I recommend using 100% argon as a shielding gas for the best results. 

3. Flux-Cored Arc Welding

The next option is flux-cored arc welding, but it’s not as efficient as the previous two methods. This is because it uses more heat, causing the wire to pass through the base metal, potentially damaging the surface.

That said, there’s still a lot to like about it. For example, you will find a protective slag that offers safety even during heavy-duty tasks. What’s more, it’s possible to reduce the heat input by using a small diameter electrode, thereby offering more control. 

Also, unlike other techniques, it doesn’t require any shielding gas, thanks to its self-shielded flux wire. Meaning, you can use it on most job sites without any hassle. 

I suggest that when using a 20-gauge sheet metal, it would be best to operate the electrodes at lower energy. As a result, it will reduce overheating and increase the wire’s chances of joining the base metal. 

The only thing to remember is that the filler metal should be thinner than the base metal. Hence, you will be able to use an inverted power source when working with thin metal sheets.

Other Popular Welding Techniques

I have discussed the three predominant welding methods, but there are other techniques that you must know about.

1. Skip Welding

No, I’m not asking you to “skip” welding; pardon my poor sense of humor, but it is one of the more well-known welding techniques. It distributes the heat evenly throughout the surface, preventing the metal from warping and leading to better fusion. 

2. Fit Up And Joint Welding

This technique allows you to achieve much-needed precision, ensuring that the wire doesn’t miss the joints and burn through the material. Hence, you need to be patient and take your time while working. 

3. Backing Bars

While most welding methods use atmospheric temperatures to distribute the heat, backing bars allow you to do the same manually. All you need to do is place these copper or aluminum bars in the required areas to prevent distortions.

Final Words