Presentation on theme: "Glaze What you need to know before you apply. What is Glaze? Glaze: –a vitreous coating to a ceramic material whose primary purposes are decoration or."— Presentation transcript:
Glaze What you need to know before you apply
What is Glaze? Glaze: –a vitreous coating to a ceramic material whose primary purposes are decoration or protection –consists of ground glass and color pigments that when heated to extreme temperatures in a kiln create a non-porous surface.
What is in glaze? Silica: Finely ground glass, has a high melting point Flux: Lowers melting point of silica. I.e. Lead Alumina: Gives glaze stability and adhesion. Coloring oxide additives: Tin: White Iron: Brown Cobalt: Blue Copper: Green Vanadium: Yellow
Glaze Preparation Dry ingredients and water are mixed together to form a smooth, even consistency. Similar in appearance to a very thick cream.
Proper glaze mixing Stir the glaze thoroughly with a whisk or your hand in the bucket before applying. Check the bottom of the bucket to check to feel if the glaze is thoroughly mixed from top to bottom. The mixed glaze should be the consistency of thick cream. If Lumpy, continue to mix or strain If thin, ask for my assistance
Before glazing… Wax Resist! Creates a barrier that resists glaze adhesion to the bisque ware. –Why is this important? Rules: –Wax bottom 1/4 of piece –After glazing, wipe excess glaze from waxed area with sponge
Technique 1 Dipping Immersing piece directly into glaze –Wax foot –Dip and hold for 3 seconds (Single color dipping only requires one dip) –Let drain, fill finger (tong) marks when dry –Wipe excess glaze off of foot
Window dipping Double window dipping okay Be careful with triple window dipping!
Technique 2 Brushing Best technique for hand-built work Nice for piece with multiple areas of different colors 3 medium coats as a rule Some glazes may require up to 6 coats We will use mostly this method of applying glaze
Technique 3 Pouring Best for large bowls, platters, and plates Must use a container to collect excess glaze This is an advanced technique and we will generally have no need for it in C/S/3D I
Technique 4 Spraying Sprayed on glaze with specialized equipment in spray booth After applied, do not touch! Nice for fading colors together We used to have a spray booth!
Special Techniques Sponge Patterning A sponge can be cut to give a raised pattern look Pattern the piece with a contrasting glaze
Special Techniques Wax Resist Design Brush design on bisque ware with wax Dip, paint, pour, or sponge on the color over the wax design
Special Techniques Underglaze Brush multi color design on bisque ware with sumi brush and cover with clear or semi- opaque glaze
Special Techniques Sumi Overglaze Brush single color design on glazed piece with sumi brush Use banding wheel to paint straight lines
Special Techniques Oxide decoration Red or Black iron oxide wash can enhance the texture of the piece. Not a glaze, and is not glossy Apply, and then wash off of highlights
Special Techniques Lusters Very low fire metallic Applied over previously glazed work Expensive!