Ceramic Cones:  Understanding the Perfect Cone Bend

Do you work in pottery or ceramics? If so, you’ve likely encountered the concept of cone temperature readings. For those new to the craft, understanding the intricacies of cone readings can be a bit like deciphering a cryptic code. But fear not, we are here to help demystify this essential aspect of ceramic firing.

Imagine this: a perfect cone, standing tall and proud, ready to undergo the transformative journey of firing (Figure 1). As it absorbs the intense heat within the kiln, it begins to bend, gradually conforming to the laws of thermodynamics. This bend, dear readers, is what we refer to as the “perfect cone.”  (Figure 2)

Many enthusiasts believe that a cone reaches its ideal temperature when it bends to a particular angle, such as pointing to three o’clock on a clock face. However, according to the instructions provided by Orton, a renowned authority in the ceramic industry, the truth lies elsewhere.

The instructions from Orton unequivocally state that the cone should be pointed at five o’clock for a complete temperature reading. This direction may seem counterintuitive at first glance, especially when compared to the commonly held belief about the three o’clock position. But here’s the crucial point: the cone’s bend should essentially align with the five o’clock mark, almost pointing straight down.  (Figure 3)

Confusion often arises when interpreting the term “90-degree bend.” Yes, Orton’s instructions mention that a 90-degree bend signifies completion, but here’s the twist: cones don’t begin their journey standing perfectly upright. Instead, they start at a slight angle. Therefore, when we talk about a 90-degree bend, we’re referring to the actual bend on the cone, not the angle at which it finishes.

In essence, the tip of the cone should point towards five o’clock for a comprehensive cone reading. It’s a subtle nuance, but one that can make all the difference in achieving optimal firing results. By understanding this fundamental principle, potters and ceramicists can fine-tune their firing processes, ensuring consistent and precise outcomes.

So, the next time you find yourself peering into the depths of a kiln, observing the graceful dance of cones as they undergo thermal transformation, remember this: the perfect cone bend isn’t just about angles and positions—it’s about unlocking the secrets of temperature control and harnessing the power of heat to create masterpieces from clay.

With this knowledge and testing, you can make informed choices about your kiln firings to make your studio and work the best that it can be.  But this is just the beginning!  Remember, the perfect cone is not just a number, precision and understanding pave the way to artistic excellence.

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-The CMW Team