Friday, 14 October 2016

Interesting effects from a new copper glaze

This year, I've spent alot of time playing around with new techniques for creating surface texture, and some of those experiments are starting to bear fruit. I'm also getting pleasing results from combinations of dolomite glazes with my black slip. Applying this glaze to a moderate thickness and firing to just the right temperature is critical in allowing the slip to show through while retaining the lovely, marble-like texture of the dolomite. Below are photos of pieces I recently fired in the electric kiln, all of which were taken up to around cone 9 with a half-hour soak.

The pots where the glaze has dripped a great deal were given a coating of a new glaze containing copper oxide and carbonate and this produces a very nice range of colours, from dark greys and greens to purple, pink and orange .. the tiny crystal-like orange spots which form in the glaze runs are rather special too. The textured orange-brown glaze on the first vase is also quite interesting as it was made from a mixture of ash from smokeless coal, plus some wood ash (50), china clay (60) plus 2% copper carbonate. The coal ash is highly refractory and doesn't flux to the same extent as wood ash .. also it seems to produce a similar colour whether fired in reduction or oxidation. I like the slightly sandy, coarse texture of this glaze as a contrast with the more shiny, runny copper glaze.

Large vase with copper glazes

Bowl with orange slip and copper glazes

Cup with dolomite glaze over black slip

Vase with slip plus three glazes

Textured vase with dolomite glaze

Bowl with dolomite glaze over black slip

Cup with copper glaze

Large vase with dolomite and copper glazes

Carved vase with copper glaze (height 38 cms)

Pebble vase with copper glaze over iron and black slips

Thanks for reading!

Never give up, the best is yet to come


  1. my favorites are the copper bowl and the pebble vases, but love them all, what wonderful results you are getting with your glaze experiments.

    1. Appreciate your kind comments, thank you. Hoping to develop a less runny version of the copper glaze too.

  2. Mark,
    Greetings from Kelso, Washington state U.S.A. Between Portland Oregon and Seattle Washington.
    I've been viewing much of your work on flickr which led me to your web site and now here. Again, I feel compelled to comment. The glazes you are getting are really very nice! Here, I especially like the richness and variation on the pebble vase. The combination of the glaze, iron and slips are working brother! Is that piece done in electric oxidation? Please, I must know as I am doing much testing in my electric kiln layering multiple glazes. I will soon be making and doing tests that include colored slips under layered glazes. Your work inspires and excites me! I'm will be setting up my gas kiln this summer and then I can continue to work in both oxidation and reduction.
    My best to you Mark!

  3. Hi Paul,

    Greetings from my home town; Congleton, Cheshire in England!

    Great to hear from you and thank you for your kind words about the work! Yes, all the pieces in this post were fired in electric oxidation to around cone 9. I have found dolomite glazes particularly good layering as they can absorb and react with slips in different ways depending on the degree of melt. They do tend to eat iron oxide decoration though, which is why I often use a black slip with additions of manganese and cobalt too.

    I'm also looking forward to spring when I'll be able to try out some of the combinations in my gas kiln as well.

    Look forward to seeing some of your results on flickr, wish you every success!