MIG welding is an extremely useful skill for any welder to have, with a multitude of different applications. When you think about it, there are probably almost no situations where it wouldn’t be useful to know how to MIG weld. There are several different variables that affect the strength of MIG welds. Some of these will be dependent on the type of metal you’re working with and the specific properties of your material, but others are universal. Here is a breakdown of some common factors that affect the strength of your MIG welds and how you can optimize your results.
How Strong is a Mig Weld?
It really depends on the type of weld and how much you use it. On average, mig welds are stronger than TIG welds. If a Mig and TIG are used equally, the Mig will be stronger. Mig is generally used for structural integrity and TIG for aesthetics. So Mig is stronger, but TIG looks better. In general, both techniques can be combined for a perfect repair.
Welding Position
- Hold the torch at a 90-degree angle to the metal and to the axis of the weld.
- Keep your elbows close to your body and not extended out away from you.
- The welding tip should be above, touching, or very close to, the surface being welded.
- Your elbows should be bent and your forearms should be parallel to each other as they are held out in front of you in an “X” position.
- Keep your head up and look straight ahead during welding so that you can easily see what’s happening on the workpiece. This will also help you keep good posture which will help prevent fatigue over time as well as improve your concentration during welding sessions for a more efficient outcome.
- Maintain a constant speed and pressure on the torch during MIG welding, keeping the arc short and the speed consistent.
- Try to keep your eyes focused on the workpiece for a more thorough understanding of what’s happening in real-time. If your eyes wander across the surface of your workpiece during welding, you’re more likely to get distracted and lose track of what you’re doing.
- The tip should not be touching or close to the surface being welded at all times, as this will cause overheating and damage to the material if it is allowed to linger too long. If possible, always maintain a distance of at least 1/16 inch between your tip and the surface being welded.
Welding Conditions
1. Arc Length
Arc length is crucial for the strength of your weld. The longer the arc, the stronger your weld. It’s important to know that this is not always true, as there is a point where longer arcs become too much of a good thing and start to hurt your weld. For example, if you have a MIG welder with a 0.035-in -thick wire and are welding steel that has poor toughness properties, it would be best to use a shorter arc length (say 0.025-in ) to minimize any cracking issues from overheating and causing brittle cracking in the material.
2. Wire Feed Rate
The higher the wire feed rate, the faster you can move through your workpiece and get more welds on it in less time. However, this also increases risk because it can lead to faster overheating and cracking at the weld root if you’re not watching out for it. The best balance between fast welding speed and less risk of cracking is going to vary depending on what type of metal you’re working with but generally speaking, when working with materials that are tough or have high melting points, you want a slower wire feed rate (say 0.05 -0.095 inch per second) while working with softer metals like aluminum at 0.125 -0.18 inch per second. In general, though, most people will agree that you should never go above 1/8-inch per second when welding aluminum.
3. Feed Rate
The higher the feed rate, the faster you can move through your workpiece and get more welds on it in less time. However, this also increases risk because it can lead to faster overheating and cracking at the weld root if you’re not watching out for it. The best balance between fast welding speed and less risk of cracking is going to vary depending on what type of metal you’re working with but generally speaking, when working with materials that are tough or have high melting points, you want a slower wire feed rate (say 0.05 -0.095 inch per second) while working with softer metals like aluminum at 0.125 -0.18 inch per second. In general, though, most people will agree that you should never go above 1/8-inch per second when welding aluminum.
4. Tension
The higher the tension, the more secure your welds will be, but it also increases risk because it can lead to faster overheating and cracking at the weld root if you’re not watching out for it. The best balance between fast welding speed and less risk of cracking is going to vary depending on what type of metal you’re working with but generally speaking, when working with materials that are tough or have high melting points, you want a slower wire feed rate (say 0.05 -0.095 inch per second) while working with softer metals like aluminum at 0.125 -0.18 inch per second. In general, though, most people will agree that you should never go above 1/8-inch per second when welding aluminum.
Wire Diameter
- The size of the wire you use will have a significant impact. The smaller the wire, the more heat is generated, which can result in a weaker weld. However, there are trade-offs to using smaller wires. The smaller wires are harder to control due to their increased length and therefore they tend to be more susceptible to slipping and binding with the workpiece. There is also the issue of how much heat will be transferred by varying wire diameters. A larger diameter wire transfers more heat than a smaller one, but with a larger diameter wire, it’s harder to control and maintain contact with the workpiece, which means that it’s also more likely that you’ll end up overheating your material and creating cracks in your welds.
- The type of metal being worked on will also affect which size of wire you should use for your MIG welds. For many materials such as aluminum or stainless steel, it’s best to stick with small diameter wires for most applications since these metals are quite soft and you don’t want them cracking under the pressure of welding them together. When working with softer metals like copper or brass, however, it may actually be better if you use larger-sized wires since these materials are less prone to cracking under pressure so they can tolerate greater amounts of heat without weakening or breaking down.
- If possible, try using different sizes of wires throughout your MIG welding process in order to see which size of wire works best for each particular application. For example, you might find that a smaller wire is too hard to control in one spot and then a larger wire is too hot to handle in another area.
- The type of rod used will also have a significant impact on the strength of your welds. The main types are flux-core and stick-style rods, with flux-core rods being generally more durable than stick-style rods but stick-style rods being easier to control and producing stronger welds.
- Stick-style welding rods are coated with a special alloy that helps them conduct heat more evenly across the whole rod and therefore they’re generally considered better for MIG weldings thicker materials such as steel or stainless steel due to their ability to transfer heat more evenly, therefore, make stronger welds since there’s no hot spot or cold spot in the weld where it’s weak or easy to break away from the workpiece.
Tip And Wire Condition
1. Tip and wire condition
In order to achieve a good quality weld, you need to have a good quality tip and wire. A dull or corroded tip can be difficult to control, which can result in inconsistent welds. A wire that is too thin for the application will also be prone to cracking. It’s always important to match the diameter of your wire with the diameter of the material you’re welding.
2. Gas Pressure
The gas pressure that you use is a huge factor in determining how strong your MIG weld is going to be. The higher the pressure, the stronger your weld will be, but it will also increase the amount of heat that’s generated and potentially cause damage to your workpiece or tooling if it isn’t properly controlled. The right gas pressure for any given application is highly dependent on many variables including material type, size of the workpiece being welded, the thickness of the metal being welded, and so on.
3. Heat input
The amount of heat input that you use is another important variable when determining how strong your MIG weld will be. Too little heat input will lead to unsatisfactory results because there won’t be enough energy put into heating up enough metal at once for a good quality joint; too much heat input could potentially cause damage by overheating or melting through parts of your workpiece or tooling if it isn’t controlled appropriately; although this varies depending on what type of metal you’re working with.
4. Cooling rate
The cooling rate is another variable that affects the strength of your weld. If you cool too quickly, your weld may be prone to cracking or chipping and if you cool too slowly, the metal could become so hot that it may overheat and crack. The right cooling rate for any given application is highly dependent on many variables including material type, size of the workpiece being welded, the thickness of the metal being welded, and so on.
Conclusion
MIG welding is an extremely useful skill to have, especially if you work in a field that requires frequent metalwork. It can be challenging to master, but the rewards are well worth it. When you’re MIG welding, it’s important to keep all of these variables in mind so that you can optimize your results and produce the strongest weld possible.
