Unless you eat fast food for every meal, you must have encountered porcelain at least a few times. The ceramic material known for its durability is used across the globe. Porcelain dishes are the image of elegance and a standard for every fancy meal. Originated in China, porcelain is no longer limited to tableware. It is also used in tiles, vases, jewelry, and bathroom fixtures.
Porcelain items are considerably expensive compared to alternative materials, so you may consider making your own. However, it is considered to be complicated to work with for beginners.
In this article, we will be discussing porcelain and how beginners can use it without facing failure.
What is porcelain?
Porcelain is a ceramic subtype that can be easily differentiated from others due to its translucence. Due to the high temperature that it is heated at, the end product is neither fully opaque nor transparent. The material has another unique feature of being non-absorbent due to its lack of pores.
Not only is it non-porous, but also hygienic for frequent usage while visually adding to the experience.
What materials are used to make porcelain?
There is no fixed composition of porcelain. Instead, each manufacturer uses a different combination of the same natural materials in varying quantities.
Although each variation has a different composition, the materials used remain the same.
Also known as China clay, Kaolin is a silicate mineral that is easy to mold and gives the porcelain product its unique translucent appearance.
This white clay is used in small quantities in most ceramics. However, while giving porcelain its unique feature, it also makes it tough to work with due to its lack of plasticity, which is the clay’s flexibility or moldability.
Animal bones are subjected to high heat and oxidized in a process known as calcination. Finally, these ground bones are added to the clay.
They provide increased stability and durability, making them helpful in making tableware. However, bone ash is mainly known for the translucence it gives to porcelain products.
Derived by heating silica sand, silica has a high melting temperature. It helps retain the pot’s structure while it is in the kiln or oven due to its ability to bind.
China stone is derived from decomposing granite and lacks iron particles. It is used for making bone china.
It contains high levels of mica, similar to petuntse. It makes porcelain non-absorbent and elastic.
Feldspar is made of aluminum silicate and flint, which is hard quartz. It aids in making the bond between particles stronger by reducing the melting point of glass.
Ball clay makes working with porcelain easier. In addition, it adds plasticity to the lacking kaolin clay.
The other minerals added to the combination help bind the complete mixture, making the final clay moldable yet strong enough to retain its structure.
What Makes Porcelain Challenging To Work With For Beginners?
Earthenware or stoneware clay is usually advised for beginners. They are easy to work with and hold their shape for long.
So, what makes porcelain so tricky to work with?
Difficult To Throw
Porcelain is difficult to deal with due to its lack of elasticity. In addition, it is not easily moldable by nature due to its closely bound particles.
When thrown on the wheel, it tends to soften and collapse quickly. As a result, beginners are usually overwhelmed due to the pace at which it needs to be handled.
Difficult To Stabilize
Grog consists of Silica and Alumina and has larger-sized particles than clay.
Usually, grog makes earthenware and stoneware clays more stable and easier to mold. However, it does not help when added to porcelain.
Risk Of Shrinkage
The small-sized particles of porcelain clay are bound tightly after firing and glazing.
It causes a more significant shrinking of the pottery piece. Also, it comes with the risk of shrinkage rapidly, which may cause it to crack in the process.
Small Mistakes Magnify Into Larger Problems
Unlike other clays, it is difficult to correct a mistake that is made while wheel throwing porcelain.
If your clay is slightly off the center of the wheel and is not corrected instantaneously, it collapses and only moves further away.
Restarting is the only option, and it can be discouraging for beginners.
Water makes clay easy to mold. However, porcelain absorbs water rapidly. Therefore, the clay needs to be shaped at the same pace that it absorbs water and becomes soft.
The line between lack of and excessive moisture in the clay is thin and challenging for beginners to identify.
Fast Working Pace Is Required
To work with this type of clay requires a speed that keeps up with the rate at which the clay is molded.
The complete process of balancing the clay on the wheel while making progress instead of allowing it to collapse is a skill that comes only with practice. It is best to start with another type of clay and then progress towards porcelain clay.
How Is Porcelain Made?
Making porcelain is not very different from other ceramics. It is only that the material is challenging to handle, which makes it necessary to work under the supervision of an expert or deal with the clay only after gaining experience.
As a beginner, you may not be able to see this process unless you source your clay from a local manufacturer who allows you to see the beginning of the process of making porcelain pots.
The clay you may choose to purchase for your pottery work begins to take form by crushing up ingredients. Each manufacturer uses a different composition of ingredients in different quantities to make their porcelain clay.
Once measured, the ingredients are crushed into tiny particles using industrial grinders and crushing machines. It helps in making a homogenous mixture at the end. Ideally, particles should be no larger than 1/10th of an inch, leaving them barely visible or identifiable.
Thus, buying clay from a reputed manufacturer is the most crucial step in achieving success while working with porcelain. If your clay has irregular size particles, it becomes difficult to work with as it loses its ability to retain its structure.
However, if you want to avoid undergoing this stressful procedure, you can directly purchase readymade porcelain clay online. So, in that case, you can use the MODOH Air Dry Flexible Porcelain Clay. It is homogenous and made to hold structure while being easy to mold. Also, it remains flexible after drying, allowing beginners to make the necessary corrections when needed.
Any unnecessary elements in the clay can make pottery with porcelain more complicated than it already is. Therefore, the crushed ingredients are put on screens to filter out any impurities.
Apart from screens, magnetic filtration is done to draw out any iron particles. It is essential as any residual iron particles will oxidize while in the kiln, giving the pottery an undesirable reddish undertone.
After removing the large and extra-fine impurities and iron particles, we now have a pure powder of desirable ingredients for porcelain clay.
This powder must be adequately mixed with water to ensure homogeneity of the mixture.
Pottery enthusiasts usually engage with the clay by forming the pot’s body. The clay can be shaped in various forms.
Just like kids mold their Play-Dohs into fun shapes, you can mold the dry clay into any desired shape or form.
A step after manually molding your pottery you can choose to throw an appropriate amount of clay on the turning wheel to mold it into a shape using water to wet and make it elastic. However, it is the most challenging way to handle porcelain.
Jiggering And Ram Pressing
Jiggering and ram pressing are two different ways to shape porcelain using preset molds. The former uses the mold on one side while the latter molds a complete figure on both sides.
This part of the process can be considered a preliminary firing. The temperature is relatively less than the actual firing process.
Any volatile substances in the pottery are vaporized at the temperature of 200℃. This process is essential to minimize shrinking.
Silica, sodium, potassium, calcium metal oxides, and Alumina lower the melting temperature of the clay.
The ingredients are ground into fine particles and purified like the clay ingredients before mixing with water to make a slurry.
The glaze adds color and details and waterproofs the porcelain pot.
Traditionally, porcelain is made by heating the constituent materials in an oven or kiln between 1200 and 1400℃. During the process, chemical compounds decompose, and gasses that have formed escape.
At this stage, liquid glass formation occurs, which facilitates the formation of tight bonds after cooling, making the structure stable and non-porous.
It is the final step of making the porcelain object. The end product is a delicate yet durable product.
Types Of Porcelain
Based on its processing, there are three types of porcelain. The differences between them are stated in a table to make them easy to compare and find the ideal type you should be working with.
|Popularity||It is the most commonly used type of porcelain. It is also known as “True porcelain.”||The least popular type of porcelain.||It is a modern discovery slowly replacing the other two types of porcelain.|
|Origin||It is the earliest type discovered in China.||It is invented in Europe to replace Chinese imports.||It is the most recently discovered type of porcelain in Britain.|
|Composition||Kaolin, feldspar, mica.||Kaolin, quartz, glass, ball clay.||Kaolin, feldspar, phosphates|
|Temperature||1400℃ or Cone 10||1200℃ Cone 5||1400℃ or Cone 10|
|Strength of the Composition||Extremely sturdy||Weakest in nature, extremely delicate to handle.||The sturdiest type of porcelain. It is most resistant to damage due to chipping or breakage.|
|Alternative Components Used in the Clay as Substitutes||Petuntse||Bone Ash||China Stone and Bone Ash.|
|Cross-Sectional Texture||Brittle in nature, smooth in texture||Chalky in texture, it may be stained due to glaze.||Smooth textured and less shiny when compared to hard-paste porcelain.|
Tips For Beginners While Working With Porcelain
Porcelain is a beautiful yet intimidating material to work with. So, by following the step-wise guide provided below, even beginners can successfully attempt to make their porcelain goods.
Have A Proper Plan
Knowing what you want can make the most significant difference in the process. So, instead of deciding as you go, make a plan and take action steps as you proceed.
Specifying the outcome you wish to obtain can help you decide on the right kind of porcelain clay for the project, making your pot sturdy, durable, and easier to work on.
Prep Your Clay
Instead of taking your clay in hand on the day, you wish to start your project, pick it up before the set date.
Play around and shape it into a cylinder to imitate what you would do on the day of beginning the project. This way, you can soften the clay and get accustomed to it.
Get Familiarized With The Wheel
Centering your clay on the wheel is especially important to avoid failure. Ensure that you are accustomed to your wheel and its functioning and have water nearby to smoothen the clay.
Do not panic while throwing your clay. Instead, focus on the center and ensure that you place your clay there to allow greater access to the wheel.
Keep A Check On The Water
While porcelain requires water to make it easier to shape, excess water can cause significant harm to its structure.
Not only can it collapse, but it can also crack in the oven or kiln. Use just enough water to make it easier to shape, not any more than that.
Porcelain is a clay type that is feared amongst beginner pottery enthusiasts. It helps create elegant pieces that are durable, sturdy, and non-porous. However, while its components result in a smooth and translucent finish, they also make working with the material difficult.
It may take a few tries for beginners to get used to the clay, but it is not as challenging as it seems. Practicing shapes that you are used to can help to get acclimated to the process of using porcelain and eventually lead to success.