How To Sand Metal – Sand Stainless Steel to a Mirror Finish


Metal is the foundation of all common architecture. The most thriving cities in the world consist of buildings which depend on its reliable rigidness to keep them atop the skyline. It’s the fundamental element in construction, but, unfortunately, metal rusts!

Every metal inevitably expires after a specific duration. Besides, stainless steel (another form of metal) is also vulnerable to losing its shine. In this article, we will teach you not only to restore the shine of steel but also how to sand metal perfectly smooth.

How to Sand Stainless Steel to a Mirror Finish

The process of sanding requires some essential tools and ingredients.

  • Orbital sander with a spinning sand disc
  • Abrasive sheets of sandpaper (80-5000 grits)
  • Superior metal lubricant to polish steel

First, you need to lay your piece of metal on a stable worktable. Assure that the table is sturdy enough to keep it in a fixed position. For the next step, spray some lubricant on the sheet, covering each part of it. 

When the steel is prepared for sanding, attach a 220-grit sandpaper to the orbital sander. Spray some lubricant on the sandpaper as well to make the sanding smoother. Start sanding in a uniform fashion, and gradually sanding every inch of the metal at a steady pace. 

Don’t sand a particular area for too long, as it might be more uneven than the rest of the surface. It might also cause divots on the steel sheet. Continue this step until most of the tarnish is sanded off the upper layer.

The metal will start to look smoother now, but you will notice several squiggly white reflective lines forming on the sheet. You will need to add an interface pad to distribute the sanding evenly. 

Next, attach a 400-grit sandpaper to the orbital sander, and spray some metal lubricant on it. Place the interface pad underneath the sandpaper and restart sanding. Sand across the white lines, and continue all around the sheet proportionately.

After a while of sanding, change the sandpaper to 800-grit and slowly work back over the stainless-steel sheet. Work along the lines in the same manner. Continuing the same procedure, sand the sheet with a 1500-grit, 3000-grit, and 5000-grit consecutively. You’ll start fading the lines away by now.

However, for the final touch, apply some aluminum polish on the steel wool, and rub it all over the steel surface. Attach the polish pad to the sand disc and pour some more polish on it. 

Start the drill and polish the sheet slowly and evenly. Before long, your stainless steel will achieve maximum shine. Continue this until you get a mirror-like finish.

How to Sand Metal For Painting

To prepare the metal surface for spray painting, wipe it clean with a rag and metal spirits. Get rid of all the dust and filth. Check for major rust. Minor rust can be removed by sanding with fine sandpaper by hand. 

More relentless rust can be taken care of using a sander and rust removal gel (available in any home improvement store). Wipe off any debris left over from the sanding.

Accordingly, use an orbital sander, and start sanding with a 120-grit sandpaper; then use 200-grit. Make sure to sand consistently around the entire surface. This will make the metal smooth and ready for painting.

Once it’s ready, cover the portions you don’t want to be painted with tape. To give it an even smoother finish, spray on primer over the metal surface. After 10 minutes of cooling time, apply another coat of primer. Let it dry for another 10 minutes.

Then, hold the spray paint can upright, and shake it for a couple of minutes. When the color is all stirred up, hold the can 10-12 inches away from the surface. Spray with even strokes of paint over the whole surface. Wait for about an hour to let the paint dry, then apply another coat with the same technique.

After 30 minutes, check for any missing areas or uneven paint job. Fix any anomalies using fine sandpaper very gently. Your paint job is done!

Conclusion

Now you know how to sand metal, whether to achieve a mirror finish or to apply fresh paint on a metal surface. However, be extra cautious when sanding metal or working with paint. Flying debris and harmful fumes might be harsh to your body. 

Therefore, always wear safety goggles and gloves. Beware of tripping over the wire when operating a sander. Keep a safe environment to ensure maximum efficiency.

David Harper

I'm David, and I've been a craft & woodworking enthusiast for over 10 years. Sanders Guide is the place where I share some tips, tricks and reviews on all things DIY, tools and of course sanding!

Recent Posts