Common Clay Complaints

Clay consistency is largely personal preference, but yes, there are limits. We do checks twice a year on all clay bodies in our warehouse. Any clay beyond what we consider to still be usable is donated or recycled. If it's getting close, we put it on clearance. Beyond that, we are always happy to do our best to meet consistency requests when asked. Local customers often ask to "poke" the clay, and that's just fine! If you are too far away to pick up, you are still welcome to request clay that is softer or stiffer (depending on your preference).  

• If your clay is too stiff try pouring a 1/4 of water over the top of the clay, seal up the bag and let it sit about 48 hours.  You can also try slamming the clay in its bag against the floor, or wedging small chunks of the clay before you begin using it.
• If your clay is too soft, try opening the bag and pulling it at least half-way down the clay.  Let it sit like that for about 4 hours. (if you live in a humid place, it will take longer.)  You can also add a fan, but do not point it directly at the clay
  

Clay cracking can be really frustrating because the cracks often don't show up until after firing.  Some cracks may be firing problems, but most are the result of stresses from the construction process.  

• S or C shaped cracks on the bottom of your pieces typically result from a lack of compression in thrown work. Clay must be compressed on the bottom of the pot, both with and in opposition to the direction the wheel is spinning to completely align the particles. 
• Horizontal cracks - the most TYPICALY reason for horizontal cracks like this is unevenness in the wall OR an unevenness in the moisture levels when adding attachments.  As a wet attachment added to a dryer piece (or vice versa), dries and shrinks, it pulls at the body of the vessel and a crack will continue until it hits some kind of "relief" spot which can absorb the stress.  The cracks related to drying, often do NOT show up until after the bisque.  BUT, there is also the added possibility of dunting, which is a firing or cooling crack.
• Dunting cracks are the result of firing or cooling too quickly. 

Great Article about Porcelain clay specifically, written by Antoinette Badenhorst