Raku Workshops Participants - Mississauga Potters' Guild

Forms & Glazing for Raku Firings

THROWN FORMS SHOULD NOT BE TOO THIN FOR BEST CHANCE OF SURVIVAL
CREATE FORMS THAT HAVE CONSISTENT WALL AND BOTTOM THICKNESS – This prevents stress points where the pieces could potentially crack when they go through thermal shock from being pulled out of the kiln and into reduction chamber
WHEN HAND-BUILDING BE SURE TO SLIP AND SCORE YOUR SEAMS!! Raku clay does have some grog in it and is quite forgiving but it’s wise to err on the side of caution to avoid unwanted fractures and cracks
MAKE PIECES OF DIFFERENT SIZES – Narrow bases fit best and are easier to remove from the kiln with tongs. Plates and bowls are not good choices as they take up too much of a footprint on the kiln shelf. If you make a tile, plate or shallow bowl it will likely be fired vertically on an edge leaning against the kiln wall

If decorating with horsehair and/or feathers you will want to burnish (buff) the pieces to a smooth, buttery surface, which best enhances this technique. Use a smooth rock, back of a spoon or packing foam sheets to “buff” the pot. Note: This technique does not employ the use of the reduction chambers, which give your raw areas the charcoal-to-black colour. If you want areas to be black on these pieces you can slip or underglaze them at the leather hard or bone dry stage before bisquing.
For glazed Raku pieces plan for the raw, unglazed areas also, like with the horsehair, as these can act as form definers, such as the rim, foot, or actual components of a glaze composition/design/ pattern. Unglazed areas can act as outlines in a pattern but do not use WAX resist for these areas as it seems to cause the areas to obtain a less intense black, perhaps it doesn’t fully burn off and seals the areas from reduction effect
Consider texture as a feature of your pot, some could be glazed some unglazed

Brush on glazes – most need 2-3 coats for a good finish
Crackle white should not be applied to thickly
DO NOT USE WAX. Use thin tape, decals, stencils – REMOVE THEM BEFORE FIRING
Leave some areas raw for contrast and emphasis of certain features of your forms
DO NOT glaze the inside or the bottoms of your pots.
If you make a lidded jar, the lid will be fired separately. You can glaze all surfaces except the surfaces that touch the kiln shelf.