Set voltage 15-19 volts, amperage 30-40 amps for 24 gauge metal. Wire feed speed should be 100-300 IPM using 0.023 or 0.030 inch wire. Maintain gas flow at 20-25 CFH. Use short stick-out and fast movement to avoid burn-through.
Voltage and Amperage
Setting a MIG welder for thin metal requires the choice of voltage and amperage that will allow not to burn the object you want to attach and manage to create a high-quality weld. If you are working with metal sheets, about 24 gauge thick, which are commonly employed for automotive repair or creating some home items, metal frames, for example, the best option will be to start with the voltage 15-19 volts.
This way, you will get the weld without the dense molten metal which can burn one layer and melt another, but with the hot metal which makes the little puddle enough to attach the sheets to one another, maintaining the shape of the metal and not burning the sheets through. As for the amperage, it also depends on the metal thickness, and it is hard to say the exact value for thin metal sheets. Still, the practical range is probably between 30 and 100 amps, but for the thin materials, like the 24 gauge sheet, you will need the lower part of the spectrum, about 30-40 amps, for example.
This way, the welder will provide the required heat to melt the wire and get the proper connection between the metal sheets, but it will not be too intense and make the metal burn or damage the material. With these settings, a DIY person can fix the mail box or create a metal frame for the lampshade, for example, at the prices much lower than the professional welders will charge for such a work. However, remember that the exact parameter depends on the material you choose and the specific MIG welder model or even a year of production. Therefore, it might be desirable to run a test on the piece of the same metal you will be using and find the required settings beforehand.
Wire Feed Speed
The choice of wire feed speed for the MIG welder affects the stability of the arc and the quality of the resulting weld in thin metal. The wire feed speed represents how fast the welding wire is pushed through the gun and into the weld joint, and it is measured in terms of the inches of the wire being applied per minute. Thin metal is most often seen in 24-gauge sheets and is used in such projects as fashioning a decorative fence for a garden or repairing the auto body of a vintage car. For these types of welding, a wire feed speed of 100-300 IPM may be put to use. At the lower end of this spectrum, the wire feed speed influences the production of the cleanest and the most minuscule bead and limited spatter – a quality essential in welding thin metal with attention to detail.
As the metal gets thicker or if a welding operation calls for significant speed, the wire feed may be pushed upward into the 300 IPM area. At this speed, larger joints are filled faster; however, the metal is more at risk for warping due to the increased heat input. For instance, the individual is fashioning thin metal art or repairing the metal body part of a vintage car. By practicing on a piece of the scrap metal, the person realizes that there is a fine balance between these two factors when the welding speed minimum and the heat input stay within reasonable limits and the weld power is maintained. Knowledge of wire feed speed offers benefits beyond the production of a visually appealing weld: it contributes to the ultimate commitment to that weld’s life and strength and is especially important when welding heat-distortion sensitive metals.
Wire Type and Diameter
The selection of the appropriate wire type and diameter is vital for MIG welding thin metal. The type and diameter of the wire directly affect the welding process’s usability, as well as the quality of the final weld. Thin metal used in crafting decorative metal artwork or intricate automotive parts will be most effectively welded using an appropriate wire with a small diameter. For the purposes of this task, 0.023-inch and 0.030-inch wires will offer the best balance between precision and strength. The 0.023-inch wire will create a weld bead of an appropriate size for metals around 24 gauge, which is commonly used in delicate and highly detailed repair work of artwork.
Its small diameter requires less heat input, which concerned hobbyists might find more inclined to ensure that the technique does not burn through the materials or distort them. The 0.030-inch wire, meanwhile, is suitable for thicker materials and demands of the weld beads to be filled more quickly in joints. Both wires are made of ER70S-6, which is chosen for its versatility and its ability to be effectively used for welding on mild steel.
The wire’s tight, crisp arc will produce good fusion and reduce spatter, and its smooth flow and good wetting will allow for stronger welds. For a DIY hobbyist or a professional completing a job with welding thin steel, the best way to use that information it to experiment on a piece and see if the results match expectations. The practice will not only allow one to get better but help ensure that the type and diameter of wire chosen are appropriate for the materials.
Gas Flow Rate
Selecting the appropriate gas flow rate is vital for MIG welding because this factor will precisely determine how well you will be able to weld different types of metal, particularly thin ones. For example, creating a product from such materials as a metal gate or fixing some parts on a bicycle frame will require approximately 20-25 cubic feet per hour . By using such an amount of gas, you will be able to protect the weld pool from the effects of the atmosphere and oxidization that may influence its low strength. CPs, or 100% CO2 and a mix of CO2 with argon, can be used based on your budget and the type of weld you want to achieve.
CO2 is less expensive and can provide a weld with deep penetration, which is suitable for slightly thicker joints, however, the argon mix is more appropriate for very thin materials where a smooth and clean weld is adopted. A hobbyist in creating custom metal artwork and fixing small things at home will benefit from being able to control the gas flow accurately. As soon as the tools are set correctly, the number of defects on a product will be reduced, and the weld will look neater.
It is also important to remember that being outdoors or in windy conditions may also require setting a higher flow rate for the gas. Otherwise, this gas will not be able to form a proper shield around the weld pool and the arc, which as a result will become porous and too weak. Changes for a proper flow rate should be conducted by estimating these initial recommendations on some test pieces to be sure how they will function for your particular welder and environment.
Technique
The entirety of the process of welding thin metal with a MIG welder is dependent on knowing the correct technique that would ensure the weld is strong without causing damage to the material. The most common welding techniques used in this case would be retaining a short stick-out, moving along the weld joint quickly, and stitch or pulse welding. The ideal stick-out in this case would be about ⅜ inch. A short stick-out would allow you to concentrate your heat more precisely, controlling the weld pool much better. When welding thin materials, this is essential, as burn through is a common problem.
Excessive heat near the thin metal will also warp it, causing additional damage in the process. This is a relatively common problem when welding sheet metal, with one of the most common applications of sheet metal being the creation of auto body panels, due to the large heat output of some of the more powerful MIG machines. Stitch or pulse welding is also very useful when working with thin metals. By welding in small bursts of heat followed by a short the pause that allows the deposited metal to cool, it is possible to make a strong weld without overall heat input being too high. For instance, automotive welding focuses on welding car panels such as wheelwells, door, frame sheets and other parts sheets.
The result is that the overall metal does not get as hot which should reduce distortion. For someone creating a metal sculpture or a lightweight metal frame, not only do those techniques make the welded piece look nicer but they also increase the structural strength of the project. With so similar materials being present in various locations, a similar technique would largely be the same across different welding applications. Regular practice would make such skills second nature.