Classifications of clay types, uses and firing
Types of clay
There are four types of clay. Earthenware clay, Stoneware clay, Ball clay, and Porcelain.All of them can be used to make pottery.
Earthenware clay are the most seasoned mud utilized by potters and happen to be the most widely recognized today. Earthenware is extremely plastic and is apprentice benevolent.
Most of the time Earthenware clay color are warm. The wet clay has a tone of Brown, red color. After firing the color of earthenware will become red, black or grey.
There are two ways to organize this process
- Reduction firing
Oxidization: The piece gets the oxygen while terminating (the final product is an orangish red terminated earthenware piece that is fit to be painted upon)
- You cut the oxygen supply by putting saw dust/husk and seal the pot with some dirt. (Dirt pot comprising of the material that should be terminated). The final result here is a dark terminated earthenware piece.
- After oxidization terminating haul out the intensely hot article and drop in delicately in a metal pot with feed/rice husk and near right away. The final result here too is a dark terminated earthenware piece that is fit to be painted upon). This procedure conveys a higher hazard factor, so either oxidization technique or the decrease (a) strategy is suggested.
Earthenware can be used for sculpting, hand-building and wheel throwing. You can create sculptures, flowerpots, and other outdoor decorations.It is mostly popular to use for making terracotta jewellery
Stoneware clays are respectably plastic, hard and nonporous. Getting it's name due to it's stone-like characteristics.
They shift in shading from white, dim, and right to brown when wet. Stoneware clay contain kaolinite with little amounts of mica and quartz.
This kind of clay can be effortlessly worked with and painted with underglazes, coats, overglazes, veneers, and so forth. Which makes Stoneware a mainstream mud to use for flatware. Utilized principally close by building and wheel tossing.
Stoneware clays have two terminating temperatures: Mid fire ranges from 2106 to 2262 ℉ (1152 to 1239 ℃) Cone 3 to Cone 7. Furthermore, High fire ranges from 2280 to 2345 ℉ (1249 to 1285 ℃) Cone 8 to Cone 10.
Ball clay are the most plastic clay and contain restricted mineral contamination.Ball clays are kaolinitic sedimentary dirts that generally comprise of 20–80% kaolinite, 10–25% mica, 6–65% quartz.
Ball clays lose shading on terminating. At the greenware stage, ball clays have a dim shading. Subsequent to terminating, they get a light buff shading. They produce a fine white shading when terminated right, making them famous among potters.
In view of the high plastic and high restricting quality, Ball clays are ordinarily utilized for floor tiles, latrine bowls, jars, furnace furniture, and silverware. Ball earth alone will in general be excessively fine and tricky for use. It tends to be utilized for wheel tossing yet is basically utilized in slip projecting.
Ball clays solidify in the wake of being terminated around 2345℉ (1285℃) Cone 10. They have one tremendous inconvenience, and it occurs during terminating. Ball clays recoil unreasonably during the terminating cycle. Thus, except if you have the aptitude or enormous enough furnace, you can't utilize ball mud all alone. Ball dirt is the best material to use for ceramics when blended in with different clays (like kaolin).
Porcelain or China earthenware production are amazingly well known, particularly for dinnerware. They are made with an enormous piece of unadulterated mineral kaolin, also called "China Clay." and different materials
Porcelains do have a shading range, yet all the hues are extremely unobtrusive and light. At the greenware stage, they'll show an exceptionally light dark ish tone. Subsequent to terminating, they are grayish to white. Porcelain coatings, and lacquers, can be applied to give shading just and needn't bother with coating to repulse water.
Kaolin clays are the least plastic clays , thus very difficult to work with. They fire at high temperatures. Porcelain is blended in with different minerals to bring down its terminating temperature and increment usefulness. For the most part utilized in wheel tossing and cast slipping to make flatware, containers, and other improving articles.