Pottery glaze melts when it is fired and will stick to the kiln shelf if it isn’t wiped off. But what about underglaze? Can you put it on the bottom of your pots, or does underglaze stick to the kiln shelf? Many types of underglaze don’t stick to the kiln shelf when they are fired. …
There are a few situations where you might need to rehydrate bone dry clay. Perhaps you have a bag of unused clay that has dried out in a big block. Maybe you have some dry unused clay scraps, or perhaps your pottery has become too dry to trim. Either way, there are some simple ways…
Clay slip is made from a mixture of clay and water. It’s the magic tool in pottery that allows you to join pieces of clay, decorate them, and also to mend your pots now and then. But can slip be used on bone dry clay, or does your clay need to be fresh or leather…
The benefit of air dry clay is that it doesn’t need to be fired in a pottery kiln. But can you use air dry clay on a potter’s wheel? Or are you better off using it for hand building? Some air dry clays are made out of materials that feel and behave like plastic. These…
To survive the firing process, your pottery needs to be bone-dry clay. Firing damp pottery can cause it to explode in the kiln. But what does bone dry mean and how can you tell if your clay is dry enough to fire? Clay is bone dry when it has lost all the moisture it possibly…
Pottery clay cracks when drying if some parts of the piece dry out more quickly than others. When clay dries, it shrinks. If one part of the clay is shrinking faster than the other, this puts an internal strain on the pottery. The clay cracks to cope with the strain.
Flashing refers to changes in the color, pattern and texture of pottery. It occurs naturally during firing when clay comes into contact with flame, wood ash or soda vapors. However, it is now a sought-after decorative effect and can be achieved in modern kilns by using flashing slips.
You may find wedging clay tricky if you have any trouble with your wrists or hands. I have had carpal tunnel in both hands, and I find most wedging techniques cause me trouble. Stack and slam wedging is a godsend and makes wedging easy. Plus, it’s quite enjoyable! Stack and slam wire wedging involves stacking…
A lot of the articles and books about firing and glazes talk about oxidation and reduction firing. These terms sound scientific and off-putting. Because they are referring to chemical processes, they are complicated. So, I decided to write an account of them that is understandable to all of us ‘non-chemists’. Oxidation occurs when there is…
