How to Weld Thin Metal
Professional Tips

How to Weld Thin Metal Using MIG and TIG

How to weld thin metal is a type of non-continuous process that’s regularly used for car body panels. The goal of using this technique is to melt a small piece of metal, allow it to cool down a little, and melt the next piece. This is a good way to avoid blowing holes.

Key Takeaway: Welding thin metals is tricky, regardless of which welding process you use. Only skilled welders should take on this task, but if you’re eager to expand your welding skills, then mastering welding thin metals can be a total gamechanger. Many pros believe that TIG is the only way to go when you need to weld thin metal, however, welding thin metals using MIG is totally possible. But with TIG, you can end up with cleaner looking, stronger welds that will last. With MIG the process isn’t nearly as clean or strong.

Continue reading to learn why skilled welders recommend TIG or MIG for thin metal welding.

The Process

If you’re welding thin metal you should utilize a butt weld using a continuous torch movement for pieces of steel that are less than a millimeter thick. This will make blowing holes less likely.

Blowing holes can usually be prevented by adjusting the setting on the welder and reducing the wire speed and amp setting. Reducing amps can also help if you’re using thin wire that’s around half a millimeter.

Pro Technique

The best way you can avoid blowing holes is to weld using short pulses and allowing two or three seconds to pass between pulses, giving the steel enough time to cool down a little. Keep in mind, the longer you wait between pulses can increase the chance that you’ll end up with pinholes between the welds and cold joints.

Finished Weld

If you’re using a MIG process for this type of welding you may run into issues such as the individual beads not fully melting into each other. This can result in weak joints. But this isn’t usually a problem with thinner metals. However, a continuous weld seam weld is a better choice if you’re working with metal that’s over one millimeter thick.

The Right Welding Process

If you’re working with metal under six millimeters thick then TIG is the way to go. For anything less than eight millimeters you’ll want to use a MIG welding machine such as the Lincoln Electric Powermig 210 Mp #K3963-1, which offers decent wire and power control.

MIG welding for beginners can provide a more straightforward learning process that’s easier to get the hang of compared to more complicated welding processes such as stick and TIG. However, at the pro level, most welders will go with TIG welding if welding thin metal is needed.

Ultimately, the type of weld process you use it up to you, but if you want the strongest, cleanest looking welds then you should learn how to use TIG for thin metals.

To learning more about TIG, stick, and MIG welders, click here to read our buyer’s guide.

Why The Pros Choose TIG

Welding thin pieces of metal using TIG can be particularly difficult. There are plenty of things that can go wrong when you’re working with a thinner metal. If you end up turning your work into a hot puddle, then regrinding isn’t exactly going to help much.

When you’re working on thin metal with a TIG welder, you can only plan for so much. There are so many factors to consider, including your foot pedal, settings, filler metal, and technique. The best way to weld thin metal with TIG is to practice, starting off with a load of practice pieces. Keeping tracking and writing down the best settings can also be very helpful.

The Right Power and Pedal

The foot pedal is one of the advantages that come with using TIG welding. The pedal allows you to precisely regulate the heat output. Between the versatility of a heat pedal and the lower power settings that a TIG welder can offer, it can be much easier for skilled users to weld thin metals including aluminum, instead of using MIG.

Get A Fine Tip on Your Tungsten

Erratic arcs can be very problematic if you’re working with a small weld joint and thinner pieces of metal. After you have cleaned the metal thoroughly with acetone in order to remove any surface residue, you should grind the tungsten electrode to a fine tip. When you do so, the wheel shouldn’t be kept perpendicular to the electrode. The electrode’s tip should be kept pointing at the front of the wheel, allowing it to grind along the length of the electrode.

Filler Metal

Using the right type of filler metal can be detrimental to the success of any welding project and much more so if you’re dealing with thin metals. The size and hardness of the filler will be important factors. Too much filler metal can end up distributing too much heat, resulting in a distorted workpiece.

What is a Heat Sink?

The heat sink involves a piece of metal that’s placed under the workpiece in order to absorb excess heat. However, experienced welders believe that if you need to use a heat sink then there must be doing something wrong with your welding technique. But for beginners, doing so can be important, at least until the welder feels more confident in their TIG skills. Using a heat sink can provide a safeguard while you learn how to adjust the settings like a pro.

Final Thoughts

TIG allows you to weld a wider variety of metals of different thicknesses and sizes. How to weld thin metals with TIG can be challenging, but many skilled welders believe that TIG welding is one of the best options out there. However, if you’re used to stick or MIG welding you will definitely want to practice with different settings and techniques before you’re ready to work on a serious project.

How to Weld Thin Metal Using MIG or TIG for Stronger Welds
Article Name
How to Weld Thin Metal Using MIG or TIG for Stronger Welds
Find out which type of welding process is recommended for welding thin metals: TIG or MIG, and how to use both processes for this type of tough welding task.