How to Perfectly Grind a Welded Corner in Two Simple Steps

When it comes to metalworking, transforming a welded corner into a smooth, blended finish may seem like a daunting task. But with the right tools and abrasives, it can actually be much simpler than it sounds. In this post, I’ll show you how to do this in just two straightforward steps. Let’s get started!

Tools and Materials

For this project, I’m working with 10-gauge steel, which will be used as a sculpture base. The welded edge has been done using MIG welding, and now I need to grind down three sides to smooth the surface. I’ll be using two types of abrasive discs to get the job done:

1. Victo Grain CC Grind – A versatile disc that’s excellent for grinding down material quickly.

2. Polyplease – A combination grinding and surface conditioning disc that’s great for finishing and smoothing.

Both abrasives will be used with variable-speed angle grinders, allowing me to adjust the speed depending on the task at hand. This flexibility is key to achieving the right finish.

Step 1: Grinding with the Victor Grain Disc

We’ll start by using the Victo Grain CC Grind disc to remove most of the weld. This disc is a little worn, but still very effective. Using a well-used abrasive gives you a realistic idea of how these tools hold up over time.

For this step, I set the grinder speed to around 4 or 5. The goal here isn’t to add a chamfer (angled edge) but to flatten the weld and remove excess material.

Here are a few things to keep in mind while grinding:

• Low pressure and a low angle are key. The CC Grind disc performs best with minimal pressure and at a very low approach angle.

• I move the grinder around frequently to help dissipate heat and avoid overheating the steel.

• If you’re using a battery-powered grinder, check the charge before you start. I didn’t check mine, and had to swap out the battery halfway through (you’ll notice this in the video). If you’re using a corded grinder, this won’t be an issue.

Overall, it took about 5 minutes to grind down 18 inches of welded corner on this sculpture base. Keep in mind, the more worn the abrasive, the longer it may take, but it still gets the job done effectively.

Step 2: Finishing with the Polyplease Disc

After grinding the weld down with the Victo Grain CC Grind disc, it’s time to switch to the Polyplease disc for the finishing step. The Polyplease disc is unique because it combines both grinding and surface conditioning in one, smoothing out the surface as it works.

For this part of the process, I set the grinder speed between 1 and 2. The Polyplease disc not only grinds but also smooths out any rough spots left from the initial grind, giving the metal a clean, uniform finish. This is especially important if you plan to apply a patina or any other surface treatments afterward.

With the Polyplease disc, I apply a little more pressure than I did with the Victo Grain disc. The goal here is to work through the surface conditioning layer and eliminate any heavy scratches from the first grind. The disc works beautifully to blend everything together, and it even adds a subtle chamfer to the corner, enhancing the overall appearance.

At this point, the metal surface is smooth and clean, ready for further treatments. For this sculpture base, the finish is 80-180 grit, which leaves a slightly textured surface that’s ideal for patina adhesion.

Why the Right Tools Make All the Difference

As you can see from this process, using the right abrasives and grinders makes a huge difference in the final result. Even though both discs I used were fairly worn, they still performed well and allowed me to achieve a smooth, blended finish.

In my experience, having the right tools is essential to working efficiently and getting the best results. The variable-speed grinders allowed me to adjust the speed for each type of abrasive, making the grinding and finishing process more effective and less time-consuming.

Another important takeaway is that specialty abrasives and tools can elevate your work to the next level. It’s not just about grinding metal; it’s about choosing the right equipment that makes the job easier and more precise.

Wrap-Up

I hope this step-by-step guide helps you understand the process of grinding and finishing welded corners. If you have any questions or tips of your own, feel free to leave them in the comments below. Don’t forget to subscribe for more helpful content, and check out my Instagram for updates on my latest projects.

Video source: YouTube: Make Everything