How To Weld Thin Metal With MIG, TIG Or Stick Welder

how to weld thin metal

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Many profession welders recommend the arc welding method for joining thin-gauge metals. However, you can address the challenges of joining thin-gauge materials with a few welding processes. Let's share some useful tips with these welding processes for thin metals. Don't miss our article on welding machines for sheet metal.

The Option Of MIG (Metal Inert Gas) Welding

The MIG welder uses electricity to melt and join metal pieces. It's tough to weld thin-gauge materials with the MIG welding technique. However, this technique is a non-continuous process that needs the material to cool before melting it again.

Other names for this technique are Gas Metal Arc Welding (GMAW) technique or the 'hot glue gun.' Choose a suitable wire and shielding gas before using the MIG welding technique for thin sheet metals. Since this technique needs a lot of experience, some level of patience can produce results. Don't forget that you'll need some tips from us too.

Beginner welders might not know that using the smallest diameter of electrode wires can produce effective results. During the MIG welding process for thin-sheet metals, your chances of avoiding a burn-through, and warping are slim. However, smaller diameter wires can give reasonable control of the welding process. 

Usually, electrode wires with smaller diameters melt thin metals with low heat levels. They prevent the base metal around the weld from getting too hot. When there's a low deposition rate mistake, welders are quick to correct it.

When Did The MIG Welding Technique Begin?

It wasn't until the 1940s before people knew about this technique. During the MIG welding process, an arc of electricity creates short circuits between a constantly fed cathode (negative terminal) and an anode (positive terminal). 

This principle applies to thin-gauge welding of automotive parts, sculpture, and metal installations. Generally, the heat from short circuits and a non-reactive (inert) gas helps to melt the thin sheet of metal. 

Also, these elements (electricity and inert gas) ensure the right mix. When the temperature reduces, the metal cools down and solidifies into a useful piece of welded metal.

How To Weld Thin Metal With MIG Welder

Set The Weld Mode

Adopting the short-circuit transfer (SCT) model for thin-gauge metals can create perfect welds. Also, the SCT mode reduces the distortion of welds over the joint. This SCT mode minimizes any appearance of (molten metal puddles) burn-through. 

It involves the transfer of low heat, but some MIG machines have preset modes for pulse-on-short-circuit and pulse-on-pulse transfers. It's a programmable feature that chooses different weld conditions.

Shielding Gas

The shielding gas is important because it determines the bead appearance. Choose shielding gases with higher concentrations of argon for SCT weld parameters. A 75 percent (argon) to 25 percent (carbon dioxide) gas mixture is ideal. 

Since argon transfers less heat than CO2, there'll less spatter during your weld. If you are welding solid wires with thin sheets of base metal, the electrode positive (EP, or reverse polarity) is the right choice.

The Choice Of Filler Metals

Use filler metals (wires) that are thinner than thin sheet metal. Most welders use wires with diameters of 0.023- and 0.024 inches for thin-sheet metalwork. Wire diameter options 18-gauge metals like stainless steel wire are 0.030 and 0.034 inches.

Torch Angle

In the SCT model, align your torch angle to prevent a burn-through. Regardless of the welding (flat, overhead, and horizontal) positions, observe short contact-tip-to-work distance. When there's much distance between metal pieces and contact tips it can produce an unstable arc.

Advantages Of MIG Welder

  • The MIG welding gun is easy to operate if you have some basic skills.
  • The welding gun's trigger comes with the stop and the start control feature.
  • MIG welds are aesthetically-pleasing.
  • It's an ideal technique for welding sculpture with thin sheets of metals.

Disadvantages Of MIG Welder

  • Its range of application is limited.
  • If the base metal is too thin or thick, MIG welders might not be the ideal option.
  • They produce heat that's too strong for thin aluminum materials, but weak for cast iron.
  • In a wet and windy environment, the MIG welding technique is not an ideal option

How To Use TIG Welders For Thin Metal Sheets

Unlike the MIG welding process, the TIG welding technique offers clean and strong welds. This technique is ideal for welding metals that have at least six millimeters of thickness. However, you must tune the TIG machine to the best settings before using it to weld thin-sheet metals.

Apply The Right foot Pedal Control And Power Setting

Normally, TIG welding machines have foot pedals. The pedal controls the heat output from your machine. When you use smaller electrodes with a lower power setting, it's easy to prevent a burn-through.

Choose A Suitable Filler Metal

Ceriated tungsten (1/16 inches), and thoriated tungsten electrodes (0.020, and 0.040 inches) are ideal for focusing the arc on thin metals. However, regular TIG welders use pointed electrodes that offer much arc control.

They can help to focus the arc at weld joints accurately. While fabricating metals with thin sheets, it's important to minimize distortion with the right filler metals. If you are TIG welding steel materials with thin sheets, focus the tungsten at the weld, and grind at a parallel angle with the length. 

Some Basic Techniques Of TIG Welders

Usually, weaving or whipping the torch leads to a warping or burn-through condition. When the arc focuses on a specific spot, it creates more heat on the base metal. When using a TIG gun, ensure a straight line of travel with the fastest speed.

When there's an uneven distribution of heat, it leads to warping and distortion of welds. Use the skip welding technique to apply a series of stitch welds, and avoid distortions.

Advantages Of TIG Welders

  • It creates fine welds on thin metals and minimizes the chance of a splatter.
  • It's a better choice when experts need to weld with precision.
  • With the tungsten rod, you can weld both thin-gauge aluminum and steel materials with ease.

Disadvantages Of TIG Welder

  • It's a technique that only expert welders can apply.
  • This style of welding uses a much steep learning curve.
  • Beginners spend longer periods trying to learn the TIG machine than MIG techniques. So, a beginner welder should start with the MIG machine (or hybrid machines) before acquiring the TIG welding skill.

How To Weld Thin Metal With Stick Welder

The Shielded Metal Arc Welding (SMAW) is another name for the stick welding process. This style of welding predates other types, but it's a simple process that ensures strong welds. When using stick welding, the electrode gets hot and melts the work-piece to form a fusion.

It's a special consumable rod with flux coats. By creating a shield around welds, this flux material helps to minimize the risk of contamination.

However, many expert welders don't use stick welding because the process generates much heat on thin materials. The chances of experiencing burn-through are very high. Also, stick welding is a technique that leaves the weld joint with a slag.

Final Note

We have discussed three basic welding processes for thin-gauge materials. They are the Stick, TIG, and MIG, welding techniques. The goal is to apply an ideal welding process that offers enough mechanical strength. We are confident that after reading this article, you'll achieve a flawless weld during your project.

Last Updated on 2 years by Richard Boyer

  • June 8, 2022
Richard Boyer

Richard Boyer has been a professional welder for over 27 years of his life, and now he is a trainer and blogger providing critical information to anyone interested in welding. He is helping out both hobbyists, novice and professional welders to learn newer and better techniques. Read more about me

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