We sieve glazes to break down clumps (and sometimes remove foreign objects)

All of your glaze particles and ingredients should go through the sieve. All we’re really doing when we’re sieving is we’re breaking up things that have clumped together.

Sometimes materials like red iron oxide, if not sieved, will cause specking. You can sieve glazes with red iron oxide to reduce specking. And depending on the mesh size of your sieve, if you use a finer mesh, a higher number, the specking will be less.

I use an 80 mesh sieve for the most part, but I have some glazes where the red iron oxide will still speck. If I use a higher mesh, like 120 or 200 mesh (which takes a lot longer for the sieving process) it helps to really homogenize and break down the particles.

I don’t even know if it’s really breaking the particles down, but it’s probably separating particles that have kind of agglomerated together, or stuck together, and it’s breaking them apart so that they’re less likely to cause specking.

So when we’re sieving, we’re sieving out debris that’s not supposed to be there. Maybe you have a cat or a dog in your studio, and there’s fuzz and hair. Or you work in a community pottery studio. I was a technician for six years and sometimes things fall in the glaze bucket. That’s what you’re sieving out. You’re sieving out things that aren’t really supposed to be in there, and you’re breaking down any lumps and clumps.

Sieving creates a nice smooth glaze for the application process

So generally, the reason why I’m sieving is because during the glazing process, the buckets are open and you’re mixing and glaze gets stuck to the sides of the containers. Then it kind of hardens. So you get these hard chunks of glaze or sludge stuck to the sides of the containers, and then when you mix that into the glaze, it gets really lumpy. So I would sieve to create a nice, smooth glaze for the application process.

Wouldn’t contaminants like dog hair be burned off in the kiln?

Contaminants do get burned off in the kiln, but they just bother me. I don’t know, it’s just one of those things. I sieve my clay recycling because I do have a dog and I have really long hair. If I have hair or something like dirt and debris in my glaze or my clay body, it just kind of grosses me out.

I want it all to be nice and clean and smooth. So yes, they do burn off in the firing. I just prefer them not to be there while I’m working with it. That’s my personal preference. But hairs and whatnot aren’t really a problem, except they just bother me. So that’s up to you.

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