I’m switching to a lowfire smooth red earthenware clay and that means finding studio glazes that will play nicely.
I’ve always worked in high or mid-fire clays, but hardly ever the earthenware clays. I did find a lovely clay from New Mexico clay that I fell in love with. I quickly created a slab mug and fired this clay successfully to cone 1. It holds coffee nicely! Plus, the clay at cone 1 turned a yummy light brown. I used a commercial cone 06 glaze on the inside and left the outside bare.
I’ve been using this simple mug for about a month. I’ve put it in the dishwasher and microwave a number of times. I’m pleased with how it has held up so I feel comfortable expanding this clay into functional dinnerware, but I’m looking to make my own glazes so that I can keep my operating costs low.
I found a cone 04 glaze on glazy.org called ‘vc transparent satin’ and used it on a couple of small items, fired them to cone 1 and as a clear base glaze, it performed great at this temperature.
Now that I have a happy base glaze, it’s time to think about colorants. I am looking for a simple pallet of only a few colors. Therefore I am trying for Turquoise, Cobalt, and Pale Yellow. I may add Avacodo Green at some point, but these are the three I’m starting with.
The copper carbonate and cobalt carbonate are both well within limits of not leaching, but I will be using the lemon slice test to be certain. That’s when a lemon slice is placed onto the glaze, wrapped and covered and left for a few days. If the glaze is going to leach off over time, the area where the lemon is placed will be considerably lighter in color.