How to sand your polymer clay

When I found out about sanding polymer clay, it was a game changer for me. As I was still developing my feel and technique with clay, I found myself sanding almost all of my pieces. Not only was it a way to smooth out fingerprints or rough patches, it was also a way to clean up unwanted bits of dust that might not have come off prior to baking.

Now that I’m a little more advanced with clay, I find myself relying on this technique less and less, but I’m always surprised when I’m able to solve a problem by sanding. And I usually always sand white clay to make it as pristine as possible.

Sanding is something you have to plan for before baking. I mean this in the sense that if you add textures and other surface additives like paint or powder pigments, you will be sanding it off. For those kinds of projects you need to take extra care to smooth and clean your clay before adding those textures and colors.

If you are using the clay all by itself, however, sanding works great as long as you plan on finishing your piece with some sort of glaze. This is the other caveat to sanding polymer clay. You can buff out the scratches quite a bit if you have enough patience and the right tools, but it will still slightly discolor your clay. The sanded areas are usually lighter in color. If you are able to sand every bit of your piece, like a flat pendant, this shouldn’t be an issue since it will all be lighter, but with my dragons, I can only sand where my fingers fit, so there are light and dark patches all around them.

Supplies:

• Your polymer clay piece, baked
•  Wet/dry sandpaper in the following grits: 220, 320, 400, and 600. You should be able to find this in hardware stores or the hardware section in Walmart.
• A bowl of water—I usually fill up my bowl with maybe 1/2″ or 1″ of water
• Paper towels (not shown)

 

New to the world of sandpaper? Grit is the term used to describe how fine a sandpaper is. The smaller the grit, the more texture you’re going to feel on your sandpaper. This means it will scratch bigger and deeper. The bigger the grit number is, the finer the sandpaper becomes.

 

I cut out a little rectangle from the bigger sheet of sandpaper, one that I can easily maneuver around my polymer clay pieces. I write the grit number on the back with a sharpie so I can remember which one it is. Once the sandpaper has worn down, I throw it away and cut out a fresh piece.

Step 1: Start with your first grit

I like to start by dipping my lowest grit of sandpaper into my bowl of water. Wet sanding polymer clay is good because it prevents the clay dust from dispersing into the air (and into your lungs). If this is something you’re going to be doing on a regular basis, it may not hurt to look into getting a respirator as an extra precaution, however. I have heard that it also helps keep the clay from scratching as much as it would when dry sanding, but I can’t attest to this personally.

I then run the sandpaper across the clay’s surface. You’ll be able to feel the difference in your clay pretty quickly. Since I can’t fully sand every surface of my dragons without breaking them in the process, I usually do what I call spot sanding. On the piece I’m using in my videos, however, the surface was open enough that I did sand the entire surface.

Dip the sandpaper into the water as needed, making sure it stays wet throughout the process. You will get water everywhere, so having paper towels nearby and under your work area will help contain the mess.

I also like to dip my piece into the water from time to time to clear the area from any clay dust that settled on the surface; this way I can see if I have something more to clean up or if I’m ready to move on.

Note: 98% of the time, the lowest grit of sandpaper from the supply list is the only grit I use. For my own process, this is enough to get rid of unwanted textures and dust but not leave scratches that show through my glaze. I recommend experimenting on test pieces to find what works best for you and your materials.

Dab the water off of your piece to see how everything is looking, and if you are happy with how it looks at this point, you can move on to step 3.

Step 2: Repeat with other grits

If you really want to step up the smooth factor in your polymer clay piece, you’ll want to repeat step 1 with the other grits, working from the next biggest number to your highest grit. In my case, I would work from 220 to 320 to 400 to 600. Skipping too many levels of grit will make your sanding much less effective, so working from one to the next will give you the best possible finish.

You can even go higher than 600 grit. In fact, if you’re looking for a super high sheen on your polymer clay, you need to get to higher grits to achieve this kind of look, and I am not equipped to share that process. Because I’m only using sandpaper to neaten and clean up my pieces as more of a spot treatment, I personally have not felt the need to explore this.

Step 3: Rinse

Once you’re completely finished with sanding, I recommend rinsing off your piece in fresh water so you’re getting rid of any clay dust that settled in the crevices (and it will). This also gives you the chance to give it one more look to see if you missed any spots.

Step 4: Dry

Using the paper towel, pat it dry. I then set it aside and let it air dry completely as we don’t want any water remaining for the next step.

While the clay may have dried up enough earlier for you to notice, you should now see that the areas you sanded are lighter than the clay that wasn’t sanded. Don’t worry! We’ll take care of this in the final step :).

Step 5: Glaze

One of the first concerns I hear when people talk about sanding clay is the change in clay color after sanding. If you do not glaze your pieces, I’m sorry to say this particular tutorial isn’t for you. There very well may be a way to sand your piece so much (and buff it after) that you don’t need glaze to fix this issue, but this is the best way I’ve found to integrate sanding into my sculpting process.

 

When I add glaze to any piece, no matter what color of clay, I’m no longer able to tell where I sanded and where I didn’t. The color difference is fixed, and I don’t feel any scratches that may have been left by the sandpaper (although I’m not usually able to feel this after sanding anyway). You may have a different experience depending on what glaze you use, but I use polyurethane, and I think that helps smooth out where I sanded my clay.

 

I did add some paint texture to this piece after sanding the clay, but here’s what this piece looked like once I was finished.

 

 

You would only see the difference if you were looking up close at the clay or picking it up and feeling it (is it weird to say I just want to hold it because of how smooth it is?), so unfortunately that doesn’t come through in photos, but the end result is so much better that I definitely think it’s worth adding to your process if you’re looking to up the wow factor of your work.