How Thick Should The Walls Of Your Pinch Pot Be?
Pinch pots are a basic form of pottery made by pinching and shaping clay with the fingers and thumbs, without the use of a potter’s wheel. The wall thickness refers to how thick the clay walls are pinched and shaped to be. This is an important consideration when making pinch pots, as the right thickness provides sufficient strength and allows the piece to be fired and glazed successfully.
Properly controlling the wall thickness helps prevent pots from slumping or collapsing when drying. It also avoids excess weight that could cause cracking or breakage. Determining the ideal thickness depends on factors like the clay type, pot size, drying conditions, and intended use. With some practice pinching evenly, beginners can learn to form walls suitable for both functional and decorative pinch pots.
Ideal Thickness
The ideal wall thickness for a pinch pot is generally between 1/4 inch to 1/2 inch (approximately 0.6 cm to 1.3 cm). This provides enough structural integrity for the pinch pot to hold its shape while drying and firing, without being overly thick or heavy.
According to The Pottery Wheel, “When you start out, it’s best to aim for a pinch pot that is around 1⁄4 inch (6mm) thick.”1 This provides a good balance of strength and minimizing the drying time needed.
As Pottery Classes explains, “However, as a general guideline, the walls of a pinch pot are typically formed to be around 1/4 inch to 1/2 inch thick (approximately 0.6 cm to 1.3 cm).”
Going beyond 1/2 inch tends to create pinch pots that are unnecessarily heavy and thick. It also substantially increases the drying time needed before firing. So for most purposes, 1/4 to 1/2 inch offers the ideal target thickness.
Thinner Walls
Walls that are too thin can cause issues with pinch pots. Thinner walls are more prone to cracking and puncturing as the clay dries (The Ultimate Guide to Perfecting the Pinch Pot). The thinner clay has less structural integrity, making it more likely to collapse, especially when wet. Pinch pots with thin walls also tend to be more fragile overall. Even after firing, thinner walls may crack or break more easily if bumped or dropped.
It takes practice and a delicate touch to successfully pinch very thin walls consistently. Beginners may find it difficult to maintain an even thickness when pinching very thin. Uneven areas with thinner spots are more prone to punctures or tears (BENCHMARK POTTERY). For those new to pinching, it is advisable to keep the walls a bit thicker until more experience is gained.
While advanced ceramic artists can create stunning works with thinly pinched walls, beginners will likely find more success and fewer frustrations working with slightly thicker walls at first. As technique improves over time, thinner walls may become easier to master.
Thicker Walls
Walls that are too thick can cause some issues when making pinch pots. According to Pottery Class Ess article “Perfecting Pinch Pot Techniques: Finding the Ideal Thickness…”, excessively thick walls can make it difficult for a pinch pot to dry properly. The thicker the clay walls, the longer it will take for the moisture to fully evaporate from the center of the pot. Thick walls also make a pinch pot much heavier than necessary, wasting clay in the process. The ideal thickness for pinch pot walls is generally between 1/4 inch and 1/2 inch thick. Going beyond that uses more clay than needed and can lead to drying issues and excess weight.
Clay Type
The type of clay used for pinch pots can impact the ideal thickness of the walls. The three main types of clay are porcelain, stoneware, and earthenware. Porcelain is the strongest and densest type of clay. It can be pinched very thin while maintaining its structure and shape. Porcelain pinch pots can have walls as thin as 1/8 inch.
Stoneware is also very strong, though not quite as dense as porcelain. Stoneware pinch pots are best around 1/4 inch thick. This provides enough strength while still being thin enough to properly dry and fire.
Earthenware is the most porous and fragile of the three clays. Earthenware pinch pots should be closer to 1/2 inch thick to prevent cracking or collapsing while drying and firing. The more open structure requires thicker walls for stability.
In summary, denser clays like porcelain can be pinched thinner, while more porous clays like earthenware need thicker walls for the pinch pot to maintain its shape and structural integrity through the drying and firing process.
Pinch Pot Size
The size of the pinch pot has an impact on the ideal wall thickness. Larger pots need thicker walls to handle the greater stresses imposed by their size. As a general guideline, smaller pots with a diameter of 3-4 inches can have walls around 1/4 inch thick. However, larger pots with a diameter of 5 inches or more should have walls closer to 1/2 inch thick for structural integrity.
According to an article on the website The Pottery Wheel, “Larger pots need thicker walls for them to be able to hold themselves up without collapsing… A large pinch pot with thinner walls may warp or slump when dried.” https://thepotterywheel.com/how-thick-should-a-pinch-pot-be/ The increased wall thickness provides support to withstand the forces of gravity on the taller pot walls and heavier overall weight of the larger amount of clay.
Drying Time
The thickness of a pinch pot’s walls will impact how long it takes the pot to dry and be ready for use or decoration. According to The Pottery Wheel, thicker pinch pot walls take longer to dry: “The thicker your pinch pot walls, the longer the overall drying time. Thin-walled pots made with smooth, grog-free clays can dry overnight. Thick-walled porous pots may take 3-4 days.”
This is because thicker clay holds onto moisture more than thinner clay. With thicker walls, moisture has more clay to pass through to evaporate from both the interior and exterior surfaces. Thinner walls provide less clay for moisture to pass through, allowing them to dry faster.
When deciding on wall thickness, consider the drying time required. If you need a fast drying time, aim for thinner walls around 1/4 inch thick. For projects requiring longer drying times before decoration or use, thicker walls around 1/2 inch can work.
Weight
Thicker walls increase the overall weight of the pinch pot. As the walls get thicker, more clay is used, adding substantial weight to the finished piece. This can become an issue for very large pinch pots, as excess weight makes the pots more difficult to maneuver while drying and firing. Extremely thick walls on a large pot also increase the risk of cracks and breaks. According to Lakeside Pottery, the larger the pot, the more clay needed per cubic inch due to thicker walls. Keeping walls slightly thinner helps manage weight for bigger pieces.
Pinching Technique
When making a pinch pot, it’s important to use the proper pinching technique to create walls of uniform thickness. Here are some tips:
- Rotate the pot continuously as you pinch – this allows you to evenly thin the walls all the way around. Don’t just pinch one spot over and over.
- Cup your hand lightly inside the pot to support the wall as you pinch from the outside. This prevents you from pinching too hard in one area and making the wall too thin.
- Pinch gradually and gently – don’t try to pinch out a large amount of clay at once. Go slowly to maintain control over the thickness.
- Use your non-pinching hand to gently compress the outside of the pot as you pinch. This evens out the wall thickness.
- Periodically check wall thickness by gently squeezing the pot. The walls should have a uniform spongy resistance all around.
- If the bottom gets too thin, set the pot down and pinch the walls from the inside, pushing outward.
Paying attention to pinching technique takes practice, but it’s the key to achieving even, consistent wall thickness in pinch pots. Supporting the walls from the inside while pinching the outside, working gradually, and frequently rotating the pot will all help create uniform walls.
Conclusion
When making a pinch pot, the ideal wall thickness tends to be between 1/4 inch to 1/2 inch. Thinner walls under 1/4 inch are prone to cracking and breaking, especially when drying. Meanwhile, thicker walls over 1/2 inch take longer to dry out evenly and add unnecessary weight. As you pinch and shape the walls, continually check the thickness by gently squeezing between your fingers. Aim to maintain walls between 1/4-1/2 inches for the best results. This thickness range allows pinch pots to hold their shape and structure without becoming too heavy or cracking easily.