So I decided to give my North Star 4″ extruder a workout this week, building two large 20lb. coil stoneware planters. I actually made the bases for the planters last week, using coils as well, then ‘threw’ each base on the wheel to smooth out what would eventually be the interior surface. I left the bases lightly covered in plastic on plaster bats for several days to get leather-hard.
The first leather-hard base was placed on the banding wheel, then scored and slipped, ready to receive the first coil. As each coil row was added, I used a wooden modeling tool to blend one row of coil with the next, then smoothed the outer sides with a small plastic rib.
The process was repeated until I had added several rows of coils and gradually widened the form to a final upper diameter of 17″. Since my extruder is installed right next to the work table, the process of cranking out coils, application, and building the form went quickly and efficiently.
Selecting just the right coil-sized die was essential for quick work, and keeping a bucket beneath the extruder made cleanup a lot easier.
Halfway through the building process I stopped building to allow the coils to set up, wedged more clay for the upper half of the form, and made some decorative tiles to later affix to the outside of the planter.
After the full height of the form was reached, I added one more coil row, this time using a slightly greater width coil to serve as the planet’s rim.
Lastly, I added some decorative surface patterns and attached the decorative tiles I had made earlier. The planter on the right below is shown further along in the drying process, and after the base was smoothed with a damp sponge.