Tag: chemistry

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New book Science for Potters

science, potters, geology, chemistry, glazes, clay

I am excited that my next book Science for Potters is coming out soon. The cover shows a pair of Atomic Bottles by Kate Malone, covered with atoms and crystals. The book will cover chemistry, geology, clay, crystals, the science behind colour and glazes. For anyone who would like to know a bit more about the science of pottery.

Science for Potters

 

Have a look at an excerpt on silica phases and eutectics: Bloomfield_May17CM

Originally published in May 2017 issue of Ceramics Monthly, pages  80-81. http://www.ceramicsmonthly.org . Copyright, The American Ceramic Society. Reprinted with permission.

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Glaze course dates 2017

Linda Bloomfield - glaze test tiles

I have been asked to teach several glaze courses in 2017.

A new pottery school is opening in Forest Row in Sussex. I will be teaching glazes there 0n 17-19 February 2017. Contact Katrina Pechal on 0789 444 7938. You can visit the school when they open in December, courses start in January with tutors including Stephen Parry and Ruthanne Tudball.

The founder Katrina Pechal says, “ I am saddened to see so many high-level ceramics courses around the country closing. My days training at Camberwell School of Art were inspiring, having lessons with famous potters like Takashi Yasadu, Colin Pearson and Ewen Henderson among others was a great privilege and I want the next generation of potters to have the same opportunities. I have noticed a recent increase in the popularity of pottery, thanks in part to the BBC’s “The Great Pottery Throw Down. I feel this is a perfect time to move to a bigger site with better facilities where I can help students to train and develop their craft”.

 Forest Row School of Ceramics will be based in the Rachel Carson building at Emerson College, set in beautiful grounds within walking distance of the village. It offers outdoor space, which Katrina needs for a kiln site (a kiln-building workshop run by Joe Finch, Potter and author of Kiln Construction (a brick by brick approach), is already planned for early next year). Emerson also has more classrooms Katrina can utilise as she expands plus affordable student accommodation it needed.

Forest Row is three miles from East Grinstead in Sussex, situated next to the idyllic Ashdown Forest yet within easy access of the M23/M25 and a short drive from Gatwick Airport, the South Downs and the creative hub of Brighton.

final-invite

 

I will also be teaching colour in glazes at West Dean College on 5-9 March (the course is now full but you can try the waiting list), and demonstrating throwing and glazes all weekend at the Scottish Potters’ Spring Workshop at Tulliallan on 10-12 March.

For anyone in London there are glaze courses at the Morley College in February and April but I will not be teaching them.

Exciting news: I will be teaching a glaze course in Belgium in 2018.

If you can’t come on a course, you can still learn from my books.

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Colour chemistry

My latest article, in Ceramics Monthly September 2016, explains the science behind colour.

Ceramics Monthly September 2016
Ceramics Monthly September 2016

Spectrum of visible light, showing wavelength in nanometers.

I am really interested in why things are coloured. When white light falls on certain objects, they absorb some colours of light and what we see are the remaining colours of light reflected from the object. Some objects, like trees and grass, use light as energy in photosynthesis and absorb red and blue light, causing them to appear green (the three primary colours which make up white light are red, blue and green). Other objects such as coloured gemstones and glazes have transition metal atoms in them, either as impurities or added intentionally. These absorb some colours of light by promoting some of their electrons to higher-energy orbitals. For example, cobalt silicate in glazes absorbs yellow light. The colour we see is the complementary colour, blue. The colour depends on the type of transition metal and the shape of the electron cloud around it, which can be different in a gemstone from in a glaze, for example, chromium impurities give a red colour in rubies but usually give a green colour in glazes. This is because the surrounding atoms in the ruby crystal are forced closer to the chromium atom than in a glaze.

Click on the link to read the full article: Bloomfield_CMSept16

Linda_Bloomfield1small
Glazes containing copper (turquoise), praseodymium (yellow), cobalt and nickel (grey).
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Chemistry for potters

I often receive emails asking about glaze problems. It seems that students on ceramics degree courses are not taught very much about science or understanding the materials, but concentrate more on learning about art and design ideas and philosophy.

In Chemistry at school, I loved the periodic table. It neatly groups the elements so that each column contains elements with similar properties which react chemically in the same way, with metals on the left and centre and non-metals on the far right. The periodic table here shows the elements found in clays and glazes. The blank spaces are elements of less interest to potters. You can find the complete periodic table here.

periodic table 2

I have been writing a book on Science for Potters for the American Ceramic Society. Several chapters are being published in Ceramics Monthly. You can read the full article on Chemistry for Potters here Bloomfield_Feb16

Originally published in February 2016 issue of Ceramics Monthly, p60-64. http://www.ceramicsmonthly.org . Copyright, The American Ceramic Society. Reprinted with permission.