Raku vs. Electric Glaze Firing Ceramics Raku vs. Electric Glaze Firing

Clay A form of mud that can be built by And then baked into Hand or Thrown on a wheel And then baked into Decorative pieces or Functional pieces

First Firing Bisque Firing This is called the Your newly formed piece must dry for 24 hours Then it is placed in an electric kiln and heated to make sure all the water is out of it. Bisque Firing

Glaze A complex mixture of minerals Your piece is painted with, dabbed on, or dipped in glaze To make it functional To decorate a piece

Glaze Firing Vitrified The glaze must have time to and be heated in order to be vitrified The ingredients reaction to each other by heat and fusion Vitrified

Electric Kiln Pyrometric Cones Heat is generated by special coils built into the walls placed on the kiln shelf so that they can be seen through tiny holes in the wall. When the kiln reaches the appropriate temperature, the cones will start to bend to indicate the end of the firing session Pyrometric Cones

Raku Comes from Japan Began in the 16th century Creates unpredictable Smoke patterns Spectacular metallic effects Crackle effect

Raku Uses a special glaze that won’t seal the piece from water Glaze will react to combustible materials while it is hot The pieces are heated in the kiln for 15-20 min. at a temperature between 1500 and 1800 degrees.

Raku The pieces are then taken out and placed into a prearranged bucket of combustible materials 15-20 min. later the pieces are dunked in cold water A 50 % chance that the piece will crack due to the rapid change of temperature Wear thick gloves and use tongs when handling the burning hot pieces

Resources http://www.mediterranean-interiors.com/en/pictures_raku.htm Copyright® 2002-2004 - Mediterranean Interiors - all rights reserved http://www.clayexpression.com/raku.firing.htm http://en.wikipedia.org/wiki/Raku http://www.dalzell.net/ceramics/firingtips1.htm