Clay is a naturally occurring sedimentary material that can be used to make beautiful crafted objects ranging from pottery to sculptures and jewelry. But if clay is heated, it can harden and become fired clay, a material that isn’t malleable like its predecessor. Is there a way to turn fired clay back into its original clay form? The answer is yes – there are ways to reconstitute fired clay and almost bring it back to its original properties. Here, we explore what fired clay is, what happens when it is fired, how to reconstitute it, the advantages and disadvantages of doing so, and the different types of clay and firing techniques available. We also have some tips on making the most of fired clay, and where to find high-quality supplies.
What is Fired Clay?
Fired clay is clay that has been heated to a high temperature in a kiln, causing it to form permanent bonds between the particles and harden. When the clay is fired, any water content and chemicals within it evaporate out. This leads to a permanent change in composition, texture, and color, resulting in a strong and durable material. Depending on the type of clay and firing methods used, different materials result. For example, terra cotta is the result of firing red earthenware clay, while porcelain is created by firing white kaolin clay. It’s these properties that make fired clay extremely useful for crafting objects.
What Happens When Clay is Fired?
When clay is fired in a kiln, the chemical and physical properties of the material are changed in a process known as ‘vitrification’. In simple terms, this means that the temperature of the kiln causes a rearrangement of the molecules within the clay. Water content is released as steam, leaving just solid particles bound together with strong permanent bonds. This gives the object a new hardness, making it resistant to water and other elements that could damage its structure.
How to Reconstitute Fired Clay
The process for reconstituting fired clay is relatively straightforward. Firstly, the material needs to be finely pulverized. This can be done using a pestle and mortar or by breaking it up with your hands. Then you need to add enough liquid until it forms a malleable paste that can be formed into shapes. It’s important not to add too much liquid as this can make the material too soggy. You can then use your hands or a potter’s wheel to shape the reconstituted clay into whatever shape you desire.
Benefits of Reconstituting Fired Clay
Reconstituting fired clay has a number of advantages. Firstly, it’s much cheaper than buying raw clay as you don’t need to buy it in bulk as you do with raw materials. As well as this, it’s much easier to work with than raw materials, meaning it’s quicker to craft objects with reconstituted clay than with raw materials. Furthermore, it has already been fired so you don’t have to worry about breaking objects during the firing process. Finally, it can be formed into any shape without cracking.
Potential Pitfalls of Reconstituting Fired Clay
Unfortunately there are also a few drawbacks when it comes to reconstituting fired clay. Firstly, if you don’t pulverize the material finely enough then there can be bits of fired clay still left in the reconstituted material which can make it slightly brittle and more prone to cracking. As well as this, there may be some loss of strength. Reconstituted material is more likely to crack if it’s subjected to drastic changes in temperature or pressure which is something you need to bear in mind when crafting with it.
Different Types of Clay and Different Firing Techniques
There are a variety of different types of clay available for use. These include earthenware clays such as red earthenware (terra cotta) or buff-burning brown stoneware, as well as kaolins such as white ball clay or porcelain. Different types of clays require different firing techniques in order to achieve the desired properties. For example, porcelain typically requires an oxidising atmosphere while terracotta needs to be fired in an atmosphere that contains a lot of carbon dioxide.
What to Consider Before Attempting Firing Clay
Before attempting to fire your chosen type of clay, there are a few things you should consider first. Firstly, you need to make sure you have all the necessary tools and equipment available – including a kiln, potter’s wheel, and appropriate glaze – as this will affect both the aesthetics and strength of the final product. Secondly, determine which firing technique is most suitable for your project – oxygen-rich (oxidizing) or fuel-rich (reducing) atmospheres are usually best for most projects – and research relevant firing temperatures for your chosen type of clay.
Tips for Making the Best Use of Fired Clay
Here are our top five tips for making the best use of fired clay:
- Know your glaze: Research what type of glaze works best for each type of clay.
- Set realistic expectations: Understand that some materials are harder to work with than others.
- Experiment: Test different glazes on your pieces before committing to a final design.
- Clean thoroughly: Make sure all tools and surfaces used are completely free from dust and other dirt.
- Be safe: Always use protective equipment such as gloves and goggles when working with clay.
Where to Find Top Quality Supplies for Working with Fired Clay
When purchasing supplies for working with fired clay, it’s important to look for high-quality materials as these will give you best results. You can purchase from specialist suppliers such as Potclays or Clay Planet – both of which offer advice on materials and surfaces suitable for use alongside their wares. Alternatively, you can do your own research and purchase direct from manufacturers such as Laguna Clay Company or Standard Ceramic Supply Company. However you choose to purchase supplies for working with fired clay, remember to ask questions and do your research first.
So there you have it – it’s definitely possible to turn fired clay back into its original clay form, but you need to exercise caution when doing so. With the right supplies, safety measures in place, and plenty of practice, you can make beautiful objects out of reconstituted fired clay just like any other material.
