News & Events

Clayfest 2018



Remember that we’ll be firing alot of pots so it’s really important that you keep to the guidelines below so everyone gets a fair share

Maximum of two pots with one reserve each, no larger than 20 cm. in diameter and 30 cm. tall and smaller if at all possible. We cannot manage flat pieces such as tiles as they take too much room in the kilns. If you have jewellery on a frame the maximum is one frame.

Clay and biscuit firing.
Please use a raku clay. I use Ashraf Hanna clay from CTM. You’ll need to biscuit fire all your pots before you bring them. Do make sure you don’t trap any air in your pots when making them as raku firing is much more rapid than normal firing and will expose flaws in making sometimes resulting in pots blowing up in the kiln. Also, if you make fully enclosed forms like pebbles, make sure that the air escape hole is larger than normal.

For naked raku, horse hair decoration and obvara decoration you should burnish the surface to as high a sheen as you can or use terra sigillata. Many people put several coats of a fine slip on the surface of their leather hard pots before burnishing. I use a slip made of 50% porcelain and 50% body clay sieved using a 200 grade sieve. I then burnish when nearly bone dry using a flat plastic spatula before biscuit firing to 960 degrees. You do not need to burnish for glazed raku pots.

Bringing ready glazed pots
If you have experience of raku work and have your own glazes it can be useful for you to bring your biscuited pot[s] with glaze already applied if you wish to. This has the advantage that we can start firing more quickly on the day.

Whatever you do – Happy Potting!

John Watson

Obvara technique. Please look up obvara on You-tube and Facebook
Books you might like to look at if you want to read further:
“Raku” Tim Andrews. A & C Black
“The Ceramics Handbooks” by John Mathieson. Raku. A & C Black. London ISBN 1-57498-166-8 Page 70-71 shows Sue Luker’s work hand building & burnishing.
“Raku. Investigations into Fire”. David Jones. The Crowood Press
“Alternative Kilns & Firing Techniques”. James C Watkins & Paul Andrew Wandless. Lark Books. New York
Knops, Ine & Ed. (2003). Rakuvaria 2. English version: ISBN 90-77266-03-8


Steps marked * must be done by one of the demonstrators/kiln operators Horse hair decoration. [Strictly not raku but smoked]
I’ve started with this because it is the easiest & you can get going quickly.
Start with a well burnished biscuit fired pot.

  • Heat the pot in the kiln to about 900 degrees [actual temp not critical].
  • Take pot from kiln with tongs & place on a solid, non-flammable surface.
    Hold horse hair at ends using gloves & hold it down onto your pot surface. This will give a black line. Repeat using your imagination to get the effect you want.
    Try also with small feathers or dry plant material, raffia etc.
    If you can, bring gardening gloves, long horse hair, feathers etc.
    Glazed raku.
    Start with a biscuit fired pot. Burnishing not needed. Apply resist if you wish [see 4. Below]

Apply glaze or glazes to the surface of your pot. See glaze list attached which gives you the glazes we will have available and the number of coats recommended. Use your imagination to create patterns if you wish.
Leave your pot in a warm place to dry..

Bring to appropriate table for firing.

  • After firing to approx. 980 and initial cooling to about 850 put it in sawdust.
  • Remove from sawdust after approx. ½ hour, cool with water if wished
    When cool, clean with water and scouring pad & admire.

Naked raku
There are more steps to this so start this one first if you are doing it.
Start with a well burnished biscuit fired pot.
Apply resist if you wish [see 4 below].
Apply a liberal coating of resist slip [number 7 in the recipes] using a brush . This stops the glaze from adhering to the pot.
Leave to dry until the surface feels dry to touch [about an hour].
Apply a liberal coat of Susan Luker Glaze [number 6 on the glaze list] with a brush.
Dry in a warm place.
Bring to appropriate table for firing.

*After firing to approx. 900 and initial cooling to about 850 put it in sawdust. *Remove from sawdust after approx. ½ hour.
Spray or splash with water. The glaze should peel off like eggshell.
When cool enough to handle pick the remaining glaze off. CARESHARP CUTTING EDGES.
Scrub with water and scouring pad & admire.
When dry [possibly at home] polish using a clear beeswax based furniture polish & admire still further.

Any areas of pot which do not have glaze on will end up smoked black. If you want controlled black lines or other marks on your pot there are a number of ways of doing this:
Before putting on glaze in 2 or slip & glaze in 3:
Make the marks you want using wax resist &/or
Mask the areas you want using tape.
After putting glaze or slip plus glaze on your pot, scratch through the glaze or slip plus glaze with a sharp instrument. Cocktail sticks work well for this. CAREAVOID BREATHING GLAZE DUST PRODUCED AND DO THIS OVER WATER TO REDUCE DUST.

Copper flashing [reduction]
Glazes containing copper [numbers 3, 4 & 5 on my list can produce attractive copper flashing if they are reduced in the sawdust. This means that the burning sawdust takes away oxygen and “reduces” the copper compounds in the glazes to pure copper. In order for this to happen the pot needs to be put into the sawdust as soon as possible after reaching 980 but after the glaze has to harden and quickly covered with a small airtight can.