Pottery Kilns

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11. More Info and Photos



It is necessary to use lined pipe with all pottery kilns, all the way from the kiln to the chimney.

We include in the price of the School Kiln No. 2 one length of lined pipe and one lined elbow, which is generally sufficient to connect it with the chimney, as it is as well to have it stand close to the flue.

The School kiln No. 2, the Studio Pottery kiln and the Melting and Muffle furnace require 7 in. diameter lined pipe. The $175 and the $250 Pottery kiln take 834 in. diameter lined pipe, and the $525 size 16 in. diameter pipe. The regular length of these pipes is 24 in.

7 in. diameter lined pipe, per length..... $3.00
Elbow..... 2.50
8 3/4 in. diameter lined pipe, per length..... 4.00
Elbow..... 3.00
16 in. diameter lined pipe, per length..... 6.50
Elbow..... 5.00
8 3/4 in. lined Tee..... 7.50
16 in. lined Tee..... 21.00

We would also suggest to those who are inexperienced in high heat work that you must not attempt to connect any kind of a high heat kiln with a lightly built chimney, or with an old one, in an old building, without having it inspected in regard to its safety. Naturally, in developing a high heat, and also in long continued heat, a strong blast is sent into the flue.

With the School Kiln No. 2 a two-brick chimney, or one which is in proper condition to be used with a heating furnace ought to be sufficiently well built.

With the Pottery kilns, intended for high heats, or for firing porcelain, the chimney must be well built, and preferably, lined with fire-brick.



Some of the finest examples of glazes with crystallization have been developed in our kilns, notably the Robineau Porcelains, cut of which may be seen herewith. We take pleasure in referring especially to letters from Mrs. Robineau and Taxile Doat in this connection.



Examples of Pewabic pottery showing matt glazes in ivory and browns. This entire product has been developed from the earliest experiments to the present point of artistic and technical interest, entirely by the means of the Revelation Pottery Kilns.





















In order to measure high heat temperatures, the eminent Ceramist and Scientist, Professor Seger, formulated a series of little clay tests of regularly increasing infusibility. These tests are known as Pyrometric Cones, and are manufactured for pottery use. They approximate the temperatures quite accurately, and have largely taken the place of other tests. A trial or two will determine the cones needed for any particular body or glaze. Two cones are used ordinarily. A little clay pinched about the base will keep them upright, and they are placed on a brick or other support in a Glost kiln, or on a piece of ware in a Biscuit kiln, raised so as to be in range of the peep hole. The lower cone will be affected first, and the top will be seen to tip gradually, until it bends to the base, and is a warning to watch the kiln closely, as the second cone will go down soon after. The firing is usually stopped when the cone is half over.

Tradition has handed down to potters a very exaggerated opinion of high heat temperatures, and it is no uncommon thing to hear a kiln-man state that he fires to about 3,000 or even 4,000 F, whereas no such heat is developed or used in the pottery industry.

Below is a list of the approximate degrees of heat shown by the melting point of Seger Cones, according to number.



To give some idea of the various heats required for different pottery materials, we will say that red brick clay, or flower pot clay fires from cone 010 to 06.

The soft pottery or Faience clays, and modeling clay; such as is used in public school work, fires from 04 to 02.

Soft Limoge clays fire at about 010 to 08.

Other lead glazes from 04 to 02.

The body known as common white ware, or earthen ware, from cone 6 to cone 8.

China body or true porcelain is developed from cone 8 to cone 10, and this is about the maximum heat ever developed in any American Ceramic industry.

A few factories in Europe claim cone 15 as their maximum heat for the higher grade of a very limited porcelain production. (End)