Thin metal sheets such as car panels need extra care for welding. Also, welding thin sheets are more difficult than welding thicker metals. And it becomes even harder with the MIG welder. Thus, many welders would suggest novice welders for bypassing MIG welding for sheet metals at first.
But we are here with you with the best tips on how to weld sheet metal with MIG welder. These tricks and tips would make MIG welding of thin sheets easy, smooth, and swift.
Thus, let’s get into the MIG welding techniques if you don’t want to ruin the entire process and the thin sheet metal too.
Step by Step Guide on How To Weld Sheet Metal With MIG Welder
When you MIG weld any metal sheet, you need to look at and take care of two things. These are-
- Burning through the sheet itself.
- Warping of the sheet, especially the edges
It is easy to create excess heat and burn through one part of the sheet. Even the most experienced welders find it hard to control the heat. It can only be achieved with patience and practice during the sheet metal welding process.
Choose the Right Electrode Wire:
It is essential to choose the right MIG electrode and wire for perfect welding of the sheet metal. We suggest you select the wire with the smallest diameter. Since the wire has less diameter, it also takes less heat.
Hence, with less space, the wire will burn or melt the least space on the sheet. On top of it, an electrode with a less diameter allows you to quickly recover any possible mistakes. In this way, the small diameter electrode will cause the least warping and burn-through.
We talked with professionals in this regard. It is suggested that you use 0.023 inches of wire for the MIG welding result. Also, choosing the right welder for beginners is important. You need to pick a versatile welder for MIG welding with infinite adjustability.
Preparing the Metal:
You will also need to prepare and clean the metal sheets before welding, especially with aluminum. Inspect the metal sheet and remove dust and dirt, if there are any. You may use a cleaning solvent or degreaser to wipe out the oil and dirt.
For removing oxidation and rust, you may even use rust or oxidation remover too. Last but not least, using a steel wire brush will help you to clean the metal sheet with the best results.
Choose the Right Setting:
You must set the MIG welding parameters rightly if you don’t want warping and burns on the sheet. You must ensure the arc goes right into the welding puddle. Also, your hands must be steady so the weld doesn’t face any weaving or whipping.
We suggest you choose the straight-line profile. Also, instead of holding the welder in the same place for too long, move it steadily and quickly from one end of the metal sheet to another end. It will prevent warping and offer a smooth bead profile.
Skip Welding Method:
Don’t worry, we aren’t recommending you to skip the entire MIG welding. The ‘skip welding’ is a welding technique. It will allow you to distribute the heat through the electrode evenly. The process refers to creating a weld hole firstly, then skin a few inches for the next weld hole. You need to continue the process until it reaches the end of the metal sheet.
For instance, if you work with 2-feet by 2-feet steel metal sheet with an 18-gauge thickness, create a 1-inch puddle or hole, firstly. Then skip 6 inches and create the next hole until you reach the end. Then, repeat the process from that end. But this time create the puddles in every 3-inch distance.
As you repeat the process, it helps in even welding with proper heat distribution.
Use Bars as Backing:
When you weld a particular portion of the sheet metal, the heat must dissipate as quickly as possible from the metal. It will prevent burns and warping of the metal sheet. We recommend you using a backing bar for this purpose.
The backing bar is commonly made of aluminum or copper. The bar will be clamped with the welding piece base and it will help in dissipating the heat quicker and better. You may even choose the backing bar with a water-cooled function for heavy-duty MIG cycles.
Joint and Fit-Up:
You need to fit and joint the thin sheet metal piece with the all welding pieces as tightly as possible. The joins must be tight and well-fitted. If there will be a gap between the two welding materials, the weld will be of poor quality.
Hence, when you start cutting the metal sheet for welding, you must measure its accuracy several times. Also, make sure that the fitting is top-class.
Tips and Tricks for MIG Welding Sheet Metal
- A MIG welder with infinite adjustability will be the best option for welding thin metal sheets. Also, a multi-purpose welder will allow you to adjust the settings to meet the requirements and matching your desires. You can adjust the voltage and wire feed configuration as well.
- For the best MIG welding output, there’s nothing better than your experience. Thus, we suggest you practice MIG welding as much as possible. You may try out different configurations and see which works best for what metal and thickness. You can use scrap metals to practice and develop your MIG welding skill.
- Using thinner electrode wire will surely result in better welding output. We have already discussed that using 0.023-inch electrode wire will yield the best welding results.
- Many welders use a long bead to weld thin metals. It runs the risk of burning the sheet more. So, we suggest you use a short burst of weld in quick time. It permits to have better control over the entire welding process.
MIG welding is a pretty challenging task, particularly when you work with a thin metal sheet. We hope this guideline including different tips on how to weld sheet metal with MIG welder helps you to achieve the best results.
Nonetheless, you must always remember that MIG welding is all about practice, practice and practice. The more experience you will have, the better the MIG welding result will be.