salt, smoke and VARIATIONS ON THE 80:20 APPLE CRACKLE GLAZE FOR RAKU

A lot of these glazes sink to the bottom of their container and set like rock overnight.

It is best to mix them as you need them ...measure by the handful then mix them with a stick with out sieving. Keep it thick and creamy

To keep them suspended or at least help the problem add Epsom Salts in the following manner: Mix 500gm Epsom Salts with 1,000gm water. This is a strong mix which you can store in a bottle. Add this to the glaze slowly in drops or very small spoonfuls until the glaze mix feels creamier and more suspended, if you know what I mean.

NB: I have used these glazes only in a decorative way and to try to create expressive surfaces. I cannot recommend them as functional food or drink bearing surfaces

First I want to say that the dark crackles result from placing the red hot glaze in to a very smoking atmosphere, or burying in sawdust, leaves, wet newspaper and the like. A white clay gives best results

BY PARTS

80 GERSTLEY BORATE :20 POTASH FELDSPER

Difficult to dip because of its thick consistency Apply with a big brush, and do not worry about the different thicknesses on the pot. Steve Mattison a fellow resident at the Kescemet Ceramic Centre applies the glaze by hand wiping the glaze in several sweeping motions that affected the direction and look af the crackle.

Experiment with additions of coloured stains to obtain infinite variety of hues and try over the top of coloures slips too.

SALTING

I have to mention that some of thre most subtle results can be obtaimes by firing unglazed pieces and at the top heat open the door of the kiln and throw in, or place with a long stick, a handful ir two of salt. Close the door quickly, do not breath the resulting fumes, and leave to simmer for a few minutes, I have been known to reach in with a long piece of angle iron and deposit a heap of dry Gerstley Borate where the design needs it at the same time as depositibf salt , As I said close the door, simmer and remove when it looks good and ,while red hot, treat with smoke. Read on.

SMOKING

When the clay is hot any burnable material placed on the piece will deposit carbon into the clay. Glaze will protect the clay from this blackening, except where the glaze crazes,

This effect only happens for a short period.of time. Once the clay has cooled that's IT!

My own preference is to use the hot surface as a "canvas" Using heat-proof gloves I like to place the sawdust or shavings in selective areas so that I get a variety of smoke, mild smoke, and clear. In that way the desiging and decorative process continues right to the last moment.

ADVENTUROUS "CIRCUS" SURFACES

Mix up a dry batch of Apple crackle - then proceed to use it as a base for half and half mixtures mentioned in the "Free and easy glazing" page. The results might not melt so much but might yield matt surfaces and textures you never dreamt of. Remember that maturation of glaze is irrelevant for decorative ceramic work

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