Welding thin metals is difficult for most welders, including beginners. This is because of the small thickness and heat sensitivity, which cause issues such as welding burn-through, weld porosity, electrode stickiness, and material distortion. If you want to master how to weld thin metal, this post has got you covered.
Luckily, – it’s possible to weld thin metal successfully, provided you use the right weld method, technique, and process. You will learn how to perfect your thin gauge sheet welding using MIG, TIG, and stick welding.
How to Weld Thin Metal?
First, – thin metal refers to materials that have a thickness of less than 3/16 inch. This can be aluminum, brass, stainless steel, or copper. Thin metals are used to make sheet metal, HVAC ductwork, and automotive body panels, among others.
Welding thin metal sheets requires high precision and consistency to produce the best results.
To achieve this, there are a few key things. They include
- Choose the right welding technique
- the right electrode or filler
- Choose the right shielding gas
- Use the right equipment settings depending on the welding method you are using and the material you are welding
- Proper joint preparation
- Understand how to control heat
- Consistent travel speed when welding
- Use the right post-welding treatment
The type of thin metal you want to weld is a great determinant of the results. It’s worth noting that some thin metals are more difficult to weld than others.
Some of the hard-to-weld include;
- High strength steels
- Nickel alloys
Apart from the hard-to-weld metals, there are some of the easiest ones to weld. Some of these easy-to-weld metals include;
- Mild Steel
- Stainless Steel
The type of welding to use is another important factor to take into consideration. There are different types, like
- Stick, and
- flux core welding.
To weld thin metal, TIG, and MIG welding are most preferred and offer the best results. They are ideal since they offer easy heat regulation, depending on whatever you are welding.
Regardless of the type of welding you are using, using the right technique will give you the best results.
It will allow you to make welds with minimal wraps, folds, and burn-through. For instance, applying the right amount of heat and time will always result in perfect welds. So, understanding your type of welding well ensures easy navigation.
To work well with reedy metal sheets, these are some of the techniques you can apply.
1. Skip Welding
One of the issues with thin metal welding is excessive heat that causes wrapping and burn-through. Skip welding is therefore one way to mitigate this.
Skip welding comes in handy to reduce metal distortion due to heat. The technique is done by making stitch-like welds (stitches) instead of one continuous weld.
The open gaps are then filled, thereby eliminating the mess caused by continuous welding.
2. Pulse Welding
Another technique for welding thin metal is pulse welding. This technique involves alternating power levels between low and high peak currents. This alternation lets the weld cool down to prevent overheating.
The alternation happens very fast and is controlled by the welding machine.
3. Spot Welding
Spot welding, or resistance spot welding (RSW) is another proven technique to weld thin metal.
This method uses pressure and electric current to weld at small points. The method uses shaped copper alloy electrodes to pass high currents to a spot for a very short period of time.
Spot welding is typically done using the resistance spot welding (RSW) welding method but can also be done using TIG and MIG.
4. Backstep Welding
Backstep welding involves welding in the opposite direction to the overall direction of progress. You can do this using either a TIG or MIG welding machine.
MIG welding is one of the most preferred methods when dealing with thin metals and sheets. It gives the welder greater control since the machine allows you to adjust the amount of heat.
The ability to regulate current and the presence of inert gas make this mode of welding a better option.
Although welding with MIG is ideal for thin sheets, you need to choose the correct wire. Preferably, choose a small-diameter wire. Thin wires don’t need a lot of heat to melt and offer more accurate deposition. Even in the case of a mistake, it’s easy to adjust without suffering huge damage.
Before welding, it’s ideal to know the thickness of your metal to choose the right wire. Additionally, there are different MIG wires for different materials like steel, aluminum, and other metals.
Another thing to note when MIG welding thin metals is the shielding gas. While there are different combinations of cooling gases, the best gas recommended for this kind of work is argon and carbon dioxide.
The main reason why this gas mixture is preferred is because argon has less heat. Also, sputtering is minimized during welding.
Maintaining the correct angle of the torch is another thing that will help you achieve great work. Keeping the tip and the sheets in close contact delivers the best results.
When it comes to technique, use a technique such as stitch welding or push welding to reduce the risk of burn-through.
TIG welding yields some of the best joints, even better than MIG. The welding method is a great option for thin sheets that are thicker than 6mm.
To enjoy creating amazing joints, setting the machine correctly is vital. Knowing how to utilize foot pedals is great since it helps prevent burnout.
After setting the machine, choose the right diameter tungsten tip. Normally, experts use between 0.020 and 0.040 inches. For very thin materials, use a machine with a lower minimum amperage range.
The choice of filler material is also vital and affects the final joint. Though the choice of material depends on what you are welding. For steel, ER70S-2 wire is preferred, while aluminum, 3003, and 5052 alloy filler material are used.
With the right filler wire and tungsten tip, what is left is precision control. Welding fast ensures there is no excessive heat accumulation that can lead to burn-through. Also, consistent velocity prevents wraps and distortion.
Avoiding too much heat at one point or uneven heat distribution. Positioning the arc at the right position and angle helps deliver a seamless weld.
When it comes to shielding gas, pure argon is the most preferred, while the best techniques are pulse welding, tack welding, and back purging.
Stick welding is best utilized in medium and thick metals. However, that doesn’t mean you can’t use it for reedy metal joining. The major problem with this kind of welding is that it doesn’t have heat control, which increases the chances of burnout.
Welding anything less than 1/8 inch thick is a tricky endeavor and has no guarantee of success. The lack of a pulsing feature like in MIG and TIG creates a challenge of heat in stick welding.
With that said, people still do stick welding on thin metals. However, it’s ideal to use a stick welder with low amperage adjustment.
The other thing to choose is electrodes, preferably E6013 or 7014. They have better results compared to others meant for thicker welds.
Apart from the choice of electrodes, cleaning the welding surface is vital. Even though stick welding is known for excellent results on rusted and dirty surfaces, thin metal is another case. The surface needs to be clean to facilitate fast welding.
How to Weld Thin Metal–In Conclusion
Welding thin metal should not scare you. If you are a beginner, practice is the only way to get to an expert level. As we have seen, TIG and MIG are the best ways to weld thin metals.
Although the two techniques are the best, they are also quite a challenge to learn and master. The best thing to do is use scrap to practice before undertaking a real project.
Besides TIG and MIG, stick welding is also possible to join reedy metals. But the quality of the work might be of lesser quality.
While some metals are difficult to work on, others are simple and ideal to practice with. Remember, it’s recommended to take personal safety seriously to avoid injuries.