Long story short, I needed a small amount of Terra Sigillata by way of alternative chemicals. Well after literally hours of research and no answers from any of the clay forums I created my own recipe for Terra Sigillata. I needed an alternative to sodium silicate as none is on hand and I’m impatient so I’d rather play kitchen chemist and see what I could come up with. It’s not rocket science. So I thought I’d share and save some folks from having to go out and find sodium silicate.
1 Parts Clay – I used a manganese wet clay (everything else calls for dry ball clay and I was not sure about using wet clay but it worked out fine)
3 Part Water
2 Teaspoons Jet Dry (for deflocculant)
Chemicals contained in Jet-Dry
Tetrasodium EDTA
Citric acid
Methylisothiazolinone
FD&C Blue #1
Water
Sodium Polyacrylate
Methylchloroisothiazolinone
Sodium cumenesulphonate
I think the Tetrasodium EDTA is the main source of deflocculant as it is used for a chelating agent and sequester and decrease the reactivity of metal ions that may be present in a product. DigitalFire lists Tetrasodium Pyrophosphate in their database of deflocculants, which is not the same as Tetrasodium EDTA but it seems to do the same thing.
The knife is a Kiridashi made from a recycled tool file by Jared Kramer Studios. The handiest knife I’ve ever known.
FireCrown Pottery 