Seattle Pottery Supply 18" Electric Pottery Kiln, 240V, Cone 10, 18" by 27" Interior Review (2026)

Who this kiln fits

This is Seattle Pottery Supply's larger 18 inch diameter kiln with a 27 inch deep interior, built for potters who are past testing small batches and need a chamber that can hold a full multi-shelf load or tall thrown pieces like vases in one firing. At roughly 4 cubic feet of interior space, it has meaningfully more room than the company's smaller kilns, which makes it a better fit for a home studio that fires regularly or a small production potter than for someone glazing the occasional test tile. The tradeoff for that capacity is that it is a larger, heavier kiln that needs a dedicated spot and proper electrical service, so it suits a garage, basement or dedicated studio room more than a spare closet.

Specs explained: voltage, breaker and firing range

The kiln runs on a 240V circuit and needs at minimum a 40 amp breaker along with a NEMA 6-50 receptacle, which is the same style of outlet used for some welders and larger shop tools, so most homes will need an electrician to add or confirm a suitable circuit before installing it. It is built with 3 inch fire brick walls and fires to Cone 10, which covers the full range from low fire earthenware through mid fire stoneware up to high fire stoneware and porcelain, so a single kiln can handle a studio's entire glaze lineup rather than being limited to low or mid fire only. The chamber includes 3 rings, and shelves are sold separately to fit the load.

Controller, build and setup in daily use

Every Seattle Pottery Supply kiln, including this one, ships with a Bartlett V6CF digital controller, which lets a potter program ramp rates, hold times and multi-step firing schedules rather than watching the kiln manually, and the same controller is used across the company's kiln line so the learning curve carries over if a studio adds a second kiln later. The company builds these by hand in Seattle, Washington, a practice it has followed since 1975, and each kiln is ETL certified and made to order rather than kept in bulk stock, so lead time runs up to about six weeks. A lid brace comes standard to make lifting and supporting the heavy lid easier, and the thermocouple sits offset from the kiln box so it can be swapped in under 10 minutes when it wears out.

How it stacks up against the smaller Seattle Pottery kilns

Seattle Pottery Supply also sells an 18 by 18 inch version with the same footprint but a shorter chamber, and a compact 12 by 9 inch kiln that runs on a standard 120V household outlet; this 18 by 27 model sits above both in capacity, trading the simpler power hookup of the small kiln for the volume a busy studio needs. Against budget imported kilns in the same rough price range, the tradeoff is the six to eight week made-to-order lead time and the need for a dedicated 240V circuit, in exchange for a kiln built and serviced by a company with decades of history making pottery equipment rather than a generic import brand.

Verdict and who should size down

This kiln is a strong fit for a potter or small studio that fires regularly, needs Cone 10 range and wants enough capacity to load multiple shelves or tall pieces at once, and who already has or can install a 240V, 40 amp circuit. Anyone working from a small apartment or without access to that kind of electrical service should look at the company's 120V 12 by 9 inch model instead, since it plugs into a standard outlet even though it fires to a lower Cone 6 and holds far less per load. For occasional hobbyists firing small batches, the smaller kiln or a shared studio kiln will likely make more sense than this one's size and setup requirements.

Frequently asked questions