Glazing PYOs

So now I’m asking. Hopefully you know what she’s talking about because I don’t. 😛 The shop has a “class” every Tuesday night where people can come and paint ceramics that are then fired and glazed. (The part I don’t understand is the the unpainted ceramics are already fired/hard, so why would they be fired again?)

Would the PYOs be able to handle that kind of treatment?
No, you can’t fire gypsum.
Ceramic clay hardens because the high heat of firing drives off the chemically combined water in the clay body. This changes it forever, making it waterproof ( meaning it will never turn back into clay) and rock hard.
Gypsum sets up by itself with a chemical reaction that bonds water into its crystaline structure.
The glazes are painted onto the once-fired ceramic piece and then it is fired again. This turns the powdery glaze into a gorgeous glass coating.
Very cool.
We use gypsum instead of slip-cast clay for Windstones, because gypsum is one of the few materials that can be cast in a flexible rubber mold,which allows the sharp detailed undercuts. If you look at ceramic figurines, they will have very few, if any undercuts.
It is fun to go to a gift shop, or antique shop and analyze what each figurine is made of by the way it looks!
I love ceramics! It is totally fascinating.Making ceramic molds and casting them is so much fun.In the back of my head I still fantasize about setting up my kiln again.

So now I’m asking. Hopefully you know what she’s talking about because I don’t. 😛 The shop has a “class” every Tuesday night where people can come and paint ceramics that are then fired and glazed. (The part I don’t understand is the the unpainted ceramics are already fired/hard, so why would they be fired again?)

Would the PYOs be able to handle that kind of treatment?
No, you can’t fire gypsum.
Ceramic clay hardens because the high heat of firing drives off the chemically combined water in the clay body. This changes it forever, making it waterproof ( meaning it will never turn back into clay) and rock hard.
Gypsum sets up by itself with a chemical reaction that bonds water into its crystaline structure.
The glazes are painted onto the once-fired ceramic piece and then it is fired again. This turns the powdery glaze into a gorgeous glass coating.
Very cool.
We use gypsum instead of slip-cast clay for Windstones, because gypsum is one of the few materials that can be cast in a flexible rubber mold,which allows the sharp detailed undercuts. If you look at ceramic figurines, they will have very few, if any undercuts.
It is fun to go to a gift shop, or antique shop and analyze what each figurine is made of by the way it looks!
I love ceramics! It is totally fascinating.Making ceramic molds and casting them is so much fun.In the back of my head I still fantasize about setting up my kiln again.

Yay! Tha makes me happy to hear because everyone is always telling me how “ugly” ceramics are. I know they are not and will NEVER be as sharp and detailed as a Windstone, but I’m still fond of them and they are fun to pour, clean, fire and paint. Glazes are a pain, but the crystals are very pretty. I’m fond of the crackle too. *shrug* I dunno, I guess it’s what i grew up with so I’ll always have a soft spot in my heart for them.