GLAZING 101 Essential Question: What is glazing and why is it an important process in Ceramics? What are the different glazing techniques?

GLAZE IS… A liquid suspension of finely ground minerals which is applied on the surface of bisque fired clay. The glaze ingredients will melt together when fired to form a glossy glass-like surface.

GLAZE The purpose of a glaze is to: 1. Decorate or add color to a ceramic piece. 2. Waterproof a ceramic object. A clay body should be glazed in order to seal pores and make it water-tight. Glazing is generally done by brushing, pouring, dipping or spraying.

GLAZE Many different colors are possible using minerals and elements as a basis for colorant. The color of the liquid glaze IS NOT necessarily the color it will be when fired. (Check glaze chart or color tiles for an idea of glaze color) When firing, the objects should be placed about ¼” apart and from the sides of the kiln to prevent the two surfaces from bonding together.

CLAY FOR DECORATING The color and texture of clay will have a great impact on the glaze. A light colored clay will have a better color response. The texture of the clay surface can make a nice contrast in the over-all effect of glazing. Glaze in a way to enhance the design of your work, not detract from what should be a well-planned project.

ADVICE So that the decoration works as a whole with the ceramic piece and that it looks convincing, plan your approach to materials and how to apply them right from the beginning. Often, a piece can be PAINTED with acrylic paints. There are many more choices of colors when using paints.

DECORATION TECHNIQUES Stencil - stippling Wax Resist Use of Oxides in combination with glaze Spraying Combing Banding Trailing Scraffito Washing back IF you want to try some advance glazing techniques, ask for some help. 

CAUSES OF DEFECTS BLISTERS AND PINHOLES: BLISTERS IN THE CLAY: Caused by bisque not being moistened before glazing. Glaze trapped in the pours of the clay. BLISTERS IN THE CLAY: A second glaze was applied over a completely dry first coat. CRAWLING OR SCALY SURFACE: Dust or oil on the clay surface. RUNNING GLAZE: Glaze was applied too heavily.

CAUSES OF DEFECTS (cont.) CRACKS IN THE GLAZE: Glaze applied too heavily – the glaze will pull apart at the cracks when fired. POOR SURFACE OR DULL SHEEN: Glaze applied too thin.

Glazing Commandments I. Rinse bisque vessel off. Make certain you are glazing ONLY bisque ware and not green ware.  II. Shake (make sure lid is tight)/stir glaze well. Should be tomato soup consistency. Check that it is food safe/ glossy/ or stone III. Glaze inside of vessel first unless it is a plate or shallow bowl. Keep fingers and hands out of glaze.

IV. 2-3 coats of Glaze. 1 coat if it is a clear glaze. V IV. 2-3 coats of Glaze. 1 coat if it is a clear glaze. V. Use a large WET sponge to clean (dry foot) bottom of vessel and up the side 1/16th of an inch. Clean lids and galleythat the lid sits in so they won’t stick together.

VI. If glaze cracks when drying, it’s too thick VI. If glaze cracks when drying, it’s too thick. Wash it off, let dry, and re-glaze vessel. VII. Wipe up glaze spills, drips, or rings left from vessels.   VIII. Place glazed vessels on the proper glaze- firing shelves.

IX. If you put glaze in a small container, pour it back into its original glaze container when finished. X. Rinse out brushes and put them back in brush holder, bristles up. Throw out any newspaper you used to glaze on.

Glazing Pinch Pots Step 1: Sketch and color to plan glazes Step 2: Pick out glazes and record glazes by sketch Step 3: Rinse off Bisque ware Step 4: Shake/ Mix Glaze (tomato soup consistency) Step 5: Apply 2-3 Layers of Glaze Step 6. Clean up work area, wash off brushes (bristles up), and return glaze to correct spot. Step 7: Place Glazed pottery on shelves outside

Pinch Pot Glaze examples

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