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How To Miter Polish Stainless Steel Like A Pro

Get professional tips on how to miter polish stainless steel, with this comprehensive guide. All the basic tools and equipment are listed, so you get pro results. With detailed information on each step, with accompanying pictures. This will be an addition to the YouTube video I published so you will have a firm foundation on how to miter polish stainless steel.

I have used the most cost-effective tools and abrasive types to keep the cost down for the DIYer.

4:29 Minute video of the whole process.

Tools and Abrasives Required To Miter Polish Stainless Steel.

  • 4 ½ or 5” Angle Grinder

If you have been welding Stainless steel you will no doubt have this handy tool. I recommend a 5” if you are just starting out. The abrasives last longer and are only a fraction most expensive. Plus they get into a fillet weld a lot easier. In my profession, I only use the 5”

  • Angle Grinder Backing Pad 4 ½ or 5”

When using a non-variable speed grinder with metal sanding discs on stainless steel a lot of heat is generated. Stainless steel has a lower thermal conductivity than carbon steel I explain it here in one of my YouTube videos. So I highly recommend using a backing pad with ribs on the face. This allows air to cool the abrasive pad extending its life of them.

It is hard to find any woven pads that are not hook and loop style. So you may need to buy one of these for the woven pads. I don’t recommend these for the sanding pads because of the heat generated by the grinders at 10,000-12,000 rpm.

Removing the Stainless Steel Weld

Before you start it is a good idea to use a soft piece of timber to clamp the workpiece onto. This will prevent any scratches on the underside when you are polishing the miter joints. Use some tape on the clamp face to prevent any scratches from the clamp too.

When it comes to any abrasives you’re going to use make sure they have not come into contact with any carbon steel or aluminum. This will contaminate the abrasives and possibly ruin your hard work.

It is also a good habit to keep all of the Stainless steel polishing pads in a box or draw away for the work area. I have learned the hard way. I had almost finished the joint and the last stage of the polishing had coarse grinding dust embedded in the finer abrasive pad. This caused scratches into the workpiece, resulting in repeating a couple of steps to remove the scratches.

With the workpiece firmly secured and the 80-grit abrasive disc installed on the angle grinder, begin by holding the face of the backing pad almost completely flat against the weld to be sanded. See the above picture.

To prevent more work than required sand with the grain of the stainless steel. This will mean you will be grinding from both sides of the joint. See picture below

Use only light pressure when removing the weld material. In the YouTube video, The material was very thin so I used a spray bottle with water to cool it every so often. You can do this, or if you have enough joints to miter polish you can do a bit on each weld joint to allow the miter to cool.

Continue to polish out the weld until it is almost completely removed.

120 Grit Abrasive Disc To Polish The Miter Joint

Before you go to the finer abrasive pad clean off the miter joint with a damp paper towel or cotton rag. The course disc will still have debris in the deep scratches from the 80-grit abrasive disc.

Repeat the above process until all of the previous coarse scratches have been replaced with the 120 Grit abrasive pad.

Red and Blue Non-woven Pads For polishing Stainless Steel Miter joint

Before going to this stage of the process ensure all of the 80 grit scratches have been removed from the miter join. These pads are expensive so it is beneficial to have the cheaper discs do the work faster and more importantly…cheaper.

Place the hook and loop backing pad onto the angle grinder and be careful to make sure the pad is centralized onto the backing pad. If it is too off-center the disc will vibrate and not work to its potential.

The miter joint will start to have very few scratches and have a dull polish to it now.

Keep using the angle grinder in line with the brushed finish of the stainless steel to minimize the work later.

Replace with the blue abrasive non-woven pad and repeat the above step. Rember to store the pads out of the way and clean them with a damp paper towel or cotton cloth. You are almost there.

Nonunitized Disc For Polishing Stainless Steel Joint

This is the final stage where you will be using the angle grinder to polish the stainless steel. You can buy these as a pad to fit the hook and loop style backing pads, but these last a lot longer and can be used for a wider application of polishing.

Still only applying light pressure, continue to keep with the grain of the stainless steel. The face of the join will be a dull finish with almost no visible scratches at all.

How To Get The Miter Polish On Stainless Steel

Using a low-tack painter’s tape carefully pace the tape from corner to corner of the miter join. I like to tape about 3”s back from the joint to protect the stainless steel from the abrasive pad when graining. I also double the tape up to avoid sanding through the tape.

Using the black abrasive pad and a hard sanding block only start over the taped joint. As you travel in line with the grain lift the abrasive off the workpiece. If you drag the abrasive back you will notice a change in the direction of the grain, spoiling the look.

When you are happy with the look gently peel the tape off and you can use the same tape to protect the other half of the miter joint. When you are graining the joint keep an eye on the edge of the tape. If the tape is getting damaged replace the tape immediately. The crisp line of the tape is what creates the look.

how to miter polish stainless steel

Polishing The Outside Stainless Steel Weld

I always leave this to the last moment of the process. When you are using the grinder to remove the outer weld or to begin the polishing of the stainless steel it is very easy to accidentally pull the angle grinder back too far off the miter edge and scratch the outside edge of the miter joint. I did this very thing as you can see from the photo below.

I only use the red abrasive pad and the unitized disc to remove the outside weld. You will need to make this call yourself. If you have too much weld reinforcement it may be better to use the 120-grit sanding pad first.

To put the grain on the outside edge is the same process as the miter. Using the course abrasive fiber pad with a hard sanding block.

Polishing The Stainless Steel Inside Weld

Most of the time these welds won’t be seen so not as much detail needs to be done here.

I use a drill-mounted buffing wheel on a cordless drill. To speed the process up I use a course-cutting compound.

Within a few seconds, the weld is clean.

Conclusion To Miter Polishing Stainless Steel.

I hope you have found this post to be helpful and can are confident you can get the same finished product. I recommend watching the related video here, to see the process in a few minutes. All of the products that are used I have attached affiliate links so you don’t have to hunt around on Amazon trying to find the right gear.

The above picture is a bar table and stool project I have done. I go into a lot of detail in the YouTube videos on the best practices when fabricating a project like this.

I will be producing another post with a more advanced and efficient way to replicate the miter with much less time soon.

Photo of author


Kieran Proven

Kieran has been welding since the age of 11, taught by his father. He loved it as soon as he struck his first arc. At the age of 20, he has been a first-class welder coded from ASME IX to high-end pharmaceutical work. The founder of Welding Empire his goal is to help anyone wanting to further their knowledge in welding. From this website to his YouTube channel.

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