can you weld stainless steel exhaust with a mig welder

Introduction

When most people think of welding, they imagine thick sparks, big machines, and complicated techniques that only professionals know how to use. But if you're someone who enjoys fixing things yourself or just getting hands-on with metalwork, you've probably asked this simple question: can you weld stainless steel with a normal MIG welder?

The short answer is yes—you can. But like many things, there are a few things you should know before you dive in. In this article, we’ll explain everything you need to know in plain language. No technical jargon, just easy-to-understand advice to help you get the job done right.

What Is a Normal MIG Welder?

A normal MIG welder is the kind of welder you might find in a small workshop, a garage, or even your own shed. It uses a wire that feeds through a gun and joins two pieces of metal together with the help of electricity and gas. It’s one of the easiest types of welding machines to use, especially for beginners.

You don't need a fancy machine to start welding stainless steel, but you do need to know a few important tips to get it right.

What Makes Stainless Steel Different?

Stainless steel is not like regular steel. It has something called chromium in it, which makes it resist rust and corrosion. That’s why it's often used in kitchens, cars, medical tools, and outdoor furniture.

But this also means that stainless steel behaves differently when you weld it. If you use the wrong technique or the wrong type of wire, you can damage the rust-resistant layer or make a weak joint. That’s why people worry whether a normal MIG welder is enough.

The good news is: it is—if you use it the right way.

What You Need to MIG Weld Stainless Steel

To weld stainless steel with a normal MIG welder, here are the basics you’ll need:

• Stainless steel wire (ideally ER308L or ER309L)
  
  
• Shielding gas (usually a mix like 98% Argon with 2% CO2)
  
  
• Clean stainless steel surfaces
  
  
• Steady hands and a bit of patience
  
  

If your welder is set up for mild steel, you'll likely have to swap out the wire and maybe adjust your gas tank. But the machine itself? It’ll do the job just fine.

Using the Right Wire Matters

Let’s say you’re welding something like a hexagonal bar made from stainless steel. This type of bar has six flat sides, and it’s often used for strong support frames or tools. If you use mild steel wire, you might get the pieces to stick together, but the weld won’t be rust-proof. Over time, moisture in the air will attack the mild steel weld, and you’ll get rust spots—right in the middle of your stainless steel project.

That’s why it’s better to use stainless wire that matches the type of stainless you’re working with. For most home projects, ER308L works great.

Clean Metal is Key

Stainless steel needs to be clean before welding. Any oil, dirt, or rust can mess up the weld and cause defects. A quick wipe with a clean cloth and maybe a little bit of alcohol or acetone will do the trick.

If you're welding something thin, like a thin wall tube, it’s even more important to clean it well. Because this kind of tubing is lightweight and doesn’t have much thickness, any dirt or mistake could cause the metal to burn through or warp. A clean surface means a clean weld.

Settings and Technique

You don’t need a high-end welder to do the job. A small 110V MIG welder can work if you’re welding thin stainless steel. For thicker pieces like steel angles, you might need a 220V welder with more power.

When welding stainless steel, it’s a good idea to use a slower wire feed speed and higher voltage than you’d use with mild steel. Also, move your hand steadily. Don’t go too slow, or you’ll overheat the steel. Don’t go too fast, or you’ll get a weak weld.

One good tip: do a few test runs on scrap pieces before working on your final piece.

Welding Different Shapes

Hexagonal Bar

As we mentioned earlier, hexagonal bar stock is strong and often used for structural supports or custom tools. It can be tricky to line up the flat sides correctly, especially if you're welding one to another shape. Tack welds (little temporary welds) can help hold the bar in place before you do the full weld.

Thin Wall Tube

Thin wall tube is commonly used in projects where you want strength but don’t want a lot of weight—like bike frames or furniture. Because it's thin, it heats up fast and can melt through easily. Using a lower heat setting and working in short bursts helps avoid damaging the tube.

Steel Angles

Steel angles are L-shaped pieces often used in shelves, frames, or outdoor structures. Welding steel angles to stainless steel is doable, but remember: if one is stainless and the other is mild steel, you should use a filler wire that works for both—usually something like ER309L.

What Happens If You Get It Wrong?

If you use the wrong wire or don’t clean the metal, your weld might:

• Look messy and uneven
  
  
• Crack over time
  
  
• Get rusty (especially where you welded)
  
  
• Be weaker than expected
  
  

The problem with welding stainless steel poorly is that it loses the very quality you chose it for—resistance to rust and strength. So it pays to take the time to set up everything properly.

Should You Try It?

Absolutely. If you’ve got a normal MIG welder and you want to try welding stainless steel, go for it. Just start small. Use scrap metal to practice. Focus on getting the technique right before tackling a big project.

Start with something simple—like a bracket, a garden hook, or a small frame. Once you’ve got a few clean welds under your belt, then you can move on to larger items like handrails or metal art.

Real-Life Examples

A lot of people start welding stainless steel when they’re building or fixing things around the house. For example:

• Building a custom barbecue frame out of steel angles
  
  
• Repairing a damaged thin wall tube on a patio chair
  
  
• Creating a tool holder using hexagonal bar
  
  
• Adding a bracket to a stainless kitchen rack
  
  

These types of small, real-life projects are perfect practice grounds. You’ll learn how different shapes handle heat and how your welder reacts to stainless steel. And when you get it right, you’ll end up with something strong, good-looking, and built to last.

Final Tips

• Use the right wire and gas for stainless steel
  
  
• Clean the metal before you start
  
  
• Adjust your settings for slower wire speed and higher heat
  
  
• Practice on scrap pieces
  
  
• Don’t mix up mild steel and stainless unless you have the right filler wire
  
  

If you take your time and follow those steps, your normal MIG welder will do just fine.

Conclusion

So, can you weld stainless steel with a normal MIG welder? Yes, you can. As long as you take the right steps and use the right materials, you can get strong, clean, and rust-resistant welds with the same welder you use for other metals.

From working with hexagonal bar to fixing a thin wall tube or joining steel angles, you don’t need fancy equipment to get great results. You just need to understand how stainless steel behaves and treat it a little differently than regular steel.

Welding is one of those skills where you get better the more you do it. And with stainless steel, a little knowledge and practice go a long way. So grab your welder, clean up your metal, and give it a try—you’ll be surprised what you can build.