Our pottery making process
Posted by Thomas Arakawa on
From a bag of clay to delivery to a customers' hand, it takes about 30 days to 45 days. Only half of it is actually making pottery. The other time, we usually spend on delivery, shows and paperwork such as keeping track of inventory, making plans, coordinating with customers and, of course, updating websites.
Planning: Our pottery making process starts with planning. We make a production schedule to specify form, size, quantity, type of clay and glaze. We make sure they will fit in our schedule and it will fill up and/or all fit to the kiln (oven). We also design the vessels, making special templates and tools. Most importantly ordering supply for our production. We go though about half a ton (1000 lb) of clay. So Kathy has an important job to forecast clay usage 1.5 month ahead and orders 10 days before use.
Production: our actual making pottery starts 10 days after the production schedule is made. What are we doing for 10 days? We finished the previous production.
Both Kathy and I make our own work and make pottery together as well. I throw pottery on a potter's wheel. It's a strange word" throw." Kathy is a hand builder.
My normal day starts around 6am with preparing clay for afternoon and taking care of thrown pots from the previous day. I work on close tasks all morning. In the afternoon, I turn the potter's wheel and make pots.
Kathy's day is similar. She would make final touches to previous day's pots in the morning. Start making new items before lunch. And finish her day's work by preparing the next day's clay slab.
Conditioning greenware ( in-process pottery before firing) is particularly important. Fast drying makes pottery break or if it is too slow we cannot move to the next process. We don't expedite or slow down the drying process, but we find a good working rhythm to collaborate with clay's habits. This obviously changes by season, so it takes a few years to get used to the seasonal rhythm.
Our normal production is about 5 to 7 days. In those days, we filled up 36 cubic feet of kiln space. How big is it? It will be about 250 to 300 soup bowls. Or about 50 vases. 
Dry and bisque firing: once 5 days of production is done, we dry pots on a rack. This process takes about 2 to 3 days in summer, 5 days in winter. As pots are completely dry (bone dry) then load into an electric kiln for first firing, "bisque fire". Firing bisque takes about 12 hours. The bisque firing takes about 12 hours, and takes about 12 hours to cool down and the pots become bisqueware.
This process takes 5 to 10 days depending on the weather. In this 10 days while drying and bisque firing the pottery. We glaze and fire the previous fired bisqueware, make plans for next production and start making new items. Yes, we are constantly dealing with 3 productions (previous, current and next) simultaneously with each production with 50 to 200 pots.
Glaze and high-fire: Kathy and I go through this process as a team. We start by sorting the bisqueware by color, which we have planned and apply glaze on the pot color by color. There are many glaze application techniques and they produce different results. Thickness of the glaze makes different results in color and texture. The different clay produces different colors from a glaze. So many variables to make different outcomes. The difficult part of glazing is that we won’t see the result until we finish firing them.
How we load the kiln makes a difference in the glaze color. The density of the load and where the pots are located in the kiln particularly makes a difference. The flame in the kiln runs through like a river of water between the glazed bisqueware. Wider the channels are flame travels slower, but narrower the channels are flame travels faster. This makes some difference in temperature. Before loading the kiln, Kathy and I sort the pottery by size, shape and glaze color and make a loading plan to ensure each pottery would be loaded to ideal place in the kiln. The glazing and loading process takes 2 days.
High-fire is the final stage of the 20 days of clay’s journey. We start firing around 5:30 am and finish them around 7pm. During the firing, pottery goes through room temperature to 2350F (1300C). In various stages we change the oxygen levels in the kiln which affects the molecular levels of the clay and the glaze. It takes little over 13 hours to fire and 36 hours to cool down.
During the 3 days of firing and cooling process, we do the first stage of the production for next, bisque fire previous production and coordinate delivery and ready for upload photos for the online store.
Yes! Pottery making is a good workout. Two of us go through 1000 lb of clay. In the whole process we pick them up and move about 20 to 25 times. And we go through this process an average of 2.5 times every month. So we each lift and move around 15,000 lb every month. It is hard work, but it's a very rewarding process.
It’s like having Christmas every 10 days. Just 30 days ago, it was just a lump of clay but through the process, they transform into objects that serve purpose and become part of my customer’s life. Unloading the kiln is a fun day for us! If you happen to be near our studio, I recommend coming on our unloading day!