Potclays 2206 Leadless Transparent Earthenware glaze, 1 kg

Recommended firing range 1040-1140°C.

Transparent glazes benefit from thin application and fast cooling.

Optimum specific gravity for 2206 is 1.47

Supplied in powder form.

For most glazes (see individual product descriptions for exceptions), sprinkle the powder into a suitable container of water, stir, then sieve through an 80’s lawn or finer. Leave to settle overnight and pour off surplus water.

Stir, then if necessary add water to achieve the desired consistency. This depends upon the porosity of the biscuitware, but normally will be around 18 - 25 oz of dry glaze per pint of water (800 - 1250 gm per litre).

As a general rule of thumb for most powder glazes mixed for dipping/pouring to an average specific-gravity of 1.4 (1.4 times heavier than water for a set amount of liquid):- 100 g glaze powder makes around 154 ml liquid glaze.

Settling may be troublesome with some earthenware or Artistic glazes, the glaze settling into a hard deposit at the bottom of the containers which is difficult to reconstitute (also known as hard-panning).

The addition of 1-3% (higher % for fritted glazes) of Bentonite to the glaze powder prior to preparation will help prevent glazes from quickly settling and such addition is therefore common practice. Even so, this may have little effect on any tendency for the glaze to set hard once it has settled. A flocculant such as Calcium Chloride or Magnesium Sulphate (Epsom Salts) added to the glaze will, however, have the effect of causing the glaze to settle in a more loosely packed arrangement of the constituent parts, which are then more easily reconstituted.

The method is to mix a little of the flocculant with hot water in a cup until no more can be dissolved (saturated solution). Leave to cool and then add a few drops only of the liquid per litre of glaze, followed by thorough mixing. Larger additions will cause the glaze to thicken (helpful if very vitreous pieces are to be dipped).