How to Keep Your Plates and Platters Flat – Ceramics by Jas

How to Keep Your Plates and Platters Flat

This week’s topic is warping- a question I get asked all the time! How do I keep my plates and platters flat.
 
In the beginning I did struggle with warping a lot. In fact, I still do but that's mostly with smaller pieces. Surprised? Well that's because, for my bigger pieces I am a lot more careful in terms of how I make them and dry them. Smaller pieces are sometimes taken for granted- I leave them exposed, assuming they won't warp, only to find out later that they do!
 
Let me share some tips that help me achieve nice flat bases:
  • One of the key things for success in hand-building is using even slabs of clay. And this becomes even more important when making flatforms like plates and large platters. Uneven slabs lead to uneven drying which results in warping. So, making sure your clay slab is rolled out evenly before you start building can prevent this common issue.
  • Another thing to focus on while hand-building is compression. If you don't compress the clay slab enough before shaping it, it can create weak areas in the structure. These weak spots are more likely to warp as the piece dries and during firing. So, be sure to compress the clay well to avoid this issue.
  • When hand-building, how you handle the clay plays a big role in whether your final piece will warp. When creating larger flat forms, be careful not to twist or turn the clay slab excessively. Clay has a memory, so improper handling during shaping can lead to warping, especially during the final firing. So, handle the clay gently and with care to avoid this issue.
  • When using molds and pottery forms, make sure that you let the clay slab set-up on the form for sometime before removing it. This helps prevent the piece from slumping or warping as soon as you take it off the form or support. So, be patient and give the clay some time to settle before moving it.
  • Finally, it's important to dry the piece slowly to ensure it dries evenly. Sometimes, you'll find that the edges dry out faster than the bottom, which can cause warping. To prevent this, cover your platter with a piece of plastic. You can use dry cleaner plastic or even cut-up regular plastic grocery bags to cover your pieces. Covering with plastic helps slow down the drying process and prevents warping.
  • Additionally, it's good practice to weigh down the base to prevent it from bowing up as it dries. You can use things like glaze bottles, kiln posts, or other items from your studio to weigh down your platter. Just make sure to place these weights on top of the plastic so they don't leave any marks on the clay. Some people use weight bags to weigh down their pieces. Weight bags are basically small cloth bags filled with sand, rice, kidney beans, or clean kitty litter. They're great for putting on top of plates and platters to help keep the base flat.
  • Another thing to be mindful of is the moisture level of the drying board you're using. If it's made of wood, it can soak up some of the moisture from your piece, potentially causing it to warp, which can affect the base of your pottery. It's a good idea to switch to a dry board if needed and move your piece over. Just make sure to do this when your piece has firmed up enough that you can lift it without distorting its shape.
  • Also, remember to check your plastic covering every day to ensure there's no moisture built-up inside. In fact, depending not he humidity levels in your studio, if required, let the piece breathe without plastic for sometime everyday till its close to bone dry. When it reaches that point, you can take off the plastic but leave the weights on. Allow the piece to dry completely before bisque firing.
Trying out these simple tricks will definitely help you in getting nice flat bottoms.
 
Hope you found these tips helpful. If you have any topics you would like to know more about, reply to this email wth your suggestions.
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