Why Does My Pottery Ping
Pottery pinging, also known as crazing, occurs due to tension between the bisque clay and the glaze.
It often appears as small spider cracks on glazed pottery.
Pinging is not a good sign, especially for pottery intended to be food safe.
Common causes of pinging include contaminated bisque, improper glaze amounts, incompatible glaze and clay combinations, and excessive moisture in the glaze.
Repairing the cracks may not always be possible, but steps can be taken to prevent pinging in future pieces.
These include stirring commercial glazes thoroughly, allowing glazes to dry completely before firing, heating and cooling pottery slowly, and avoiding movement during firing.
Different types of vessels are affected by crazing differently, with porcelain being more prone to it than stoneware.
Pinging can weaken pottery and attract germs, so preventing it is important.
Did You Know?
1. The sound of pottery “pinging” during firing is caused by the water molecules trapped inside the clay expanding and forcefully escaping as steam.
2. The pitch of the “ping” can indicate the quality of the pottery. A higher pitch suggests that the vessel is well-made and has fewer imperfections.
3. The term “ping” actually originates from ancient Chinese pottery, where a clear, resonant sound was highly valued and admired.
4. Different types of pottery, such as porcelain or stoneware, can produce distinct “ping” sounds due to variations in their composition and firing temperatures.
5. The phenomenon of pottery “pinging” was a significant discovery for early potters, as it demonstrated the successful firing process and ensured the durability and strength of the pottery.
What Is Pinging In Pottery?
When we talk about pottery pinging, we are referring to a phenomenon known as crazing, which is a common occurrence in pottery. Crazing is characterized by the appearance of small spider cracks on the surface of a glazed piece of pottery. These cracks are caused by the tension that develops between the bisque clay piece and the glaze during the firing process.
The term “pinging” is used to describe this phenomenon because when you gently tap a pot with crazing, it can produce a high-pitched sound, similar to a ping. This sound is often a sign that there are cracks present and that the pottery may not be in optimal condition, especially if it is intended to be food safe.
- Crazing refers to the appearance of small spider cracks on glazed pottery.
- It is caused by tension between the bisque clay and glaze during firing.
- Pinging is the term used when a pot with crazing produces a high-pitched sound when tapped.
- The presence of cracks and pinging may indicate that the pottery is not in optimal condition, particularly if it is meant for use with food.
“Pinging” is a term used to describe the high-pitched sound produced when a pot with crazing is tapped.
Causes Of Pinging And Crazing In Pottery
There are several common causes of pinging and crazing in pottery. One of the main causes is contaminated bisque. If the clay used for the bisque is contaminated with impurities or foreign particles, it can create tension when the glaze is applied, leading to cracks.
Another cause is the improper amount of glaze. If too much glaze is applied, it can create excessive tension on the pottery during firing. Conversely, if too little glaze is applied, it may not adequately bond with the clay, leading to cracks.
Incompatible combinations of glaze and clay body can also lead to pinging and crazing. Different types of clay have different coefficients of expansion, and if the glaze and clay body do not have compatible coefficients, it can result in cracks.
Excessive moisture in the glaze can also cause pinging. If the glaze has too much water, it can create steam during the firing process, which can lead to cracking.
How To Prevent Pinging In Pottery
While repairing the tiny cracks caused by pinging may not always be possible, there are measures that can be taken to prevent pinging in future pottery pieces.
Some important steps to consider are:
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Stir commercial glazes with lots of water thoroughly before application. This helps to ensure that the glaze is properly mixed and reduces the risk of crazing.
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Allow glazes to dry completely before firing in the kiln. If the glaze is not fully dry, the moisture can create steam during firing, leading to pinging.
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Open the kiln gradually after firing to prevent thermal shock and cracks in the pottery. Let the kiln cool down before opening it. This slow temperature change helps to reduce the likelihood of pinging.
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Heat up and cool down pottery slowly to minimize the tension that can cause crazing.
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Ensure that pottery remains stationary during the firing cycle. Movement can create stress on the pottery, increasing the likelihood of cracks.
These measures can help prevent pinging and maintain the quality of pottery pieces.
The Importance Of Understanding Pottery Pinging
Understanding pottery pinging is crucial for both beginner and experienced potters. Crazing can weaken the structure of the pottery, making it more susceptible to breaking. Additionally, the cracks created by pinging can serve as a haven for germs and bacteria, potentially compromising the safety of foodware.
Different types of vessels are affected by crazing differently, with porcelain tending to craze more than stoneware. This knowledge can help potters choose the appropriate clay body for their desired outcome.
Furthermore, deliberate induction of crazing for decorative purposes should be approached with caution. Intentionally creating crazing weakens the pottery and increases the chances of it breaking. Careful consideration should be given to the long-term structural integrity of the piece.
Tips For Avoiding Pinging In Pottery Making
To avoid pinging in pottery making, paying attention to the type of glaze used and focusing on the smallest details are crucial. Here are some tips to prevent pinging:
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Adjust the glaze recipe: Modifying the ratio of ingredients can help fix pinging issues. Experimentation and testing are essential to finding the right glaze combination for each specific clay body.
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Control temperature dynamics: Sudden changes in temperature can cause the glaze to contract or expand rapidly, leading to cracks. Ensure a slow and gradual temperature change during the firing and cooling process to help prevent pinging.
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Avoid opening the kiln prematurely: Although it’s tempting to see the results of a firing immediately, opening the kiln too soon can create thermal shock on the pottery, resulting in pinging. Patience is key, so allow the kiln to cool down naturally to preserve the integrity of the artwork.
In conclusion, by diagnosing cracks and taking appropriate measures, potters can prevent pinging in their works. Understanding how to prevent pinging will not only improve pottery-making skills but also ensure the longevity and safety of the finished pieces.
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Frequently Asked Questions
What is glaze pinging?
Glaze pinging is a fascinating phenomenon that occurs when a glaze exhibits a fault known as “crazing.” Crazing transpires when the glaze undergoes more shrinkage compared to the clay body, resulting in the pottery experiencing significant tension. To alleviate this tension, the glaze cracks, producing a distinct pinging sound. This natural occurrence provides insight into the delicate balance between the clay and glaze during the firing process, highlighting the intricate interplay of materials in pottery creation.
What noise does ceramic make?
Ceramic objects can produce a clinky sound for various reasons. One notable scenario is during the glaze firing process, as the ceramic cools down. The cooling temperature causes the glaze to contract and solidify, resulting in small cracks or fissures called crazing. When gently tapped, these tiny cracks can create a delicate clinky noise. Another instance where ceramic may produce a clinky sound is within the first month after firing when crazing is occurring. As the ceramic adjusts to environmental changes, the stress within the glaze can cause it to crackle and emit a subtle clinking sound.
What happens if you glaze too thick?
If a glaze is applied too thick, several potential issues may arise. Firstly, if the glaze has a high surface tension at the melt stage, it can result in blistering during firing. The excess thickness of the glaze can trap gases or create uneven heat distribution, leading to the formation of blisters on the surface of the fired ware. Secondly, if the glaze contains too much clay, it can result in excessive shrinkage during drying. This excessive shrinkage can cause the glaze to crack, and subsequently, during firing, it may even crawl or move away from the desired areas. Lastly, fluid melt glazes that are applied too thick will simply run off the ware, as the excess thickness makes it difficult for the glaze to adhere to the surface properly.
How long should glaze dry before firing?
To ensure proper firing and prevent potential cracking or other defects, it is recommended to let the glaze dry for at least overnight after application. This allows the water within the glaze to evaporate fully, reducing the chances of sudden moisture release during firing. Alternatively, incorporating a pre-heat period in the firing schedule can also help in drying the glaze thoroughly before reaching higher temperatures. Taking these precautions can contribute to better results and preserve the integrity of the pottery.