My consept scetch, or a mini-miniagama.
Minigama
This is my summer 24 project and I will update this page as I progress.
According to the descriptions in Akira Yoshida book, a Minigama is a small 60-centimeter pottery kiln hand-built with traditional Raku clay. After it’s dried and burned it’s ready to be used as a “one Sake cup” kiln, and can reach 1200 degrees Celsius in about 3 hours. This makes it an interesting low-cost test kiln. I guess the name Minigama is a humorous comment to the traditional Asian Anagama kiln, which it also borrows a few concepts from. To make sufficient airflow into this small kiln, it uses a hairdryer to blow air under the charcoal (the combustion material of choice). In my opinion, this simple idea combines traditional ceramic kiln concepts with ideas from the blacksmith. It’s such a simple construction, but it redefines the principles of the traditional pottery kiln. If a motor makes the pressure, you don’t need a draft, if you don’t need a draft, you don’t even need a pipe. Every wood-fired kiln tries to balance the air intake, the firebox, and the wares chamber, against the pipe, to make the right draft. But the hairdryer is the new kid on the block. The Minigama has absolutely some challenges of its own, blowing directly into the fire makes sparks spray around like a Fontane, and a kiln built in clay it’s just doomed to crack (or worse). Still, this is a dream come true for me. It is certainly possible to model your own mini wood-fired kiln that works! (with some issues).
The author and ceramist Akira Yoshida has written a lot of books in Japanese, also about the Minigama and other mini-kilns. But Japanese is not my strong side: https://www.amazon.com/stores/Akira-Yosida/author/B004LP9V1O
Here it all started for me, with this small booklet, which I do believe is a translation of only the essentials of Mr. Akira’s kilns. If Mr. Akira is the inventor of this kiln type, or the story about its origin, is not described. Here is the front cover of the English booklet:
Read my review of the book here:
One question that makes the Minigama so interesting is why this small device can reach high temperatures in just three hours? Sure the hairdryer makes a fire on Steoroids. But that’s just part of the answer, and I think the thin walls is the other reason. Thick walls with a huge isolating potential, also take a lot of time to heat up. The Minigama hardly has mass to heat up. As an example; dug-out-sandbank-kilns take many days to fire, not necessarily because the pottery needs it, but it’s the time needed to heat up the surrounding sand to high enough temperatures.
The flames themselves are hot enough, it’s all about incapsulating them, but thick incapsulation also needs to be heated. read more about flame temperatures on Wikipedia:
https://en.wikipedia.org/wiki/Flame
I’m convinced it’s possible to mix together a Fireclay for the Minigama that handles the heat and doesn’t crack up. Read about refractory materials and Fireclay here:
https://www.woodfireceramic.com/how-to-make-fireclay/
Different Minigama movie clips I found on YouTube:
Links on the Internet:
https://elenorwilson.blogspot.com/2013/07/small-japanese-kiln-sequel.html
CMU 442 Kiln Construction Jake Allee: Project 1 (alleekilnclass.blogspot.com)