Successful Glazing at Lakeside Pottery’s Studio

Successful glazing is determined by:

2) Knowing how to read the glaze behavior in the tile sample board

3) The amount of glaze used and knowing where & how to apply the glazes

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1) Pot Design - Think of glazing as if your pot is covered with honey. When the kiln reaches the glaze melting temperature the glaze moves down with gravity. Some move more then others (see tile samples to determine glaze movement). Therefore, the surface texture of the pot, it's angles and trimming techniques will determine where glaze will accumulate and where it will run.

a. Surface Texture - impressions, lines and cavities in the clay will accumulate more glaze than smooth surfaces; on edges, the glaze will be thinner. Therefore, the glaze will be more translucent where it is thin and more opaque where it built up thicker glaze. In most glaze types you'll see the difference in color between thin and thick glaze accumulation and in some you will hardly notice (see sample tile board).

b. Trimming Techniques - Too much glaze or when glaze is applies too close to the pot's bottom will cause the glaze to drip to the kiln shelf and ruin your pot and the kiln shelf. The flow to the bottom can be eliminated by applying the right amount of glaze, providing enough glaze "travel" distance before it reaches the bottom and by creating a break in the surface of the pot. See illustrations below:

Good Designs Has a "Break Point"

Undesirable Designs – No “Break Point”

If you made pots with the undesired design illustrated above, please make sure you DO NOT apply glaze at least ¼" from the bottom .

2) How to Read the Glaze Tile - The glaze sample tiles where designed to illustrate what the end result will look like and are divided to three sections: Dipping glazes, brush-on glazes and under-glazes.

a. Determine how much the glaze move when fired by looking for different in color between an "edge" and a "valley" in the test tile. The larger the difference, the more it "moves". You can also tell how much it moves by touching the bottom surface of the glaze on the tile sample. More glaze accumulation on the bottom indicates more movement.

b. Dipping glaze sample tiles show results of approximately 5 seconds dipping. In glazes that do not move much, apply additional 1 second after the first layer dried if more opaque affect is desired.

c. Brush-on glaze sample tiles show results of three glaze layers

d.

Left side – no clear glaze

Right side – w/clear glaze

1 layer

2 layers

3 layers

Under glaze sample tiles shows one layer, two layers and three layers. It also show results with clear glaze and without clear glaze. Two to three brush-on clear glaze coats are required on top of the under glaze. Be careful not to smear your under-glazes.

Under glaze tile sample

3) The Amount of Glaze Used and Knowing Where & How to Apply Glazes

With dipping or brushing glazes, remember to not apply glaze on the bottom of your pot and on a ¼” above the bottom. Not leaving ¼” clearance from the bottom, may result in damaging the pot and kiln’s shelf. Make sure the ceramic piece is clean and free of dust or clay particles. Touch-up with a glaze brush as needed

a. Dipping Glaze - You must first mix the glaze thoroughly. Stir it again before each dip. If the glaze is too hard to mix by hand, use the drill with a mixer blade. Not mixing well will result is disappointing results. Before starting make sure there is enough glaze in the container to cover the pot and that the container is large enough to allow you to maneuver the tongs and pot.

Typical amount of time for dipping is 5 seconds. For darker color, dip additional one second with glazes that do not "move" too much. Using two glaze types dipping is not recommended being that it is hard to determine how liquidy the combination of the two glazes be. If you really wish to "double dip", the second dip should not exceed 1 -2 second and the total time should not exceed 5 - 6 seconds. To avoid glaze contamination, wait for the first dip to dry before dipping the second.

Use dipping tongs to hold the ceramic bisque while dipping. Dip with a smooth motion in and out of the glaze, using wrist action to turn the ware in the glaze. Keep ware from touching the sides and bottom of dipping container as the glaze coating may be rubbed off by contact areas. As you removed the ware from the dipping container, shake any drips off and back into the glaze. Before placing dipped ceramics on a rack to dry, finger-smooth any drips or runs. Clean the bottom of your piece. It should be free of glaze ¼" from the bottom. Wash the tongs after each use to prevent contamination.

Glaze can be poured into a cavity and poured out after 5 seconds. Do the inside first and then dip the outside surfaces (see illustrations below).

Matte or crackled glazes are not recommended for use on food containers (can build up bacteria and may be hard to clean).

b. Brush-on Glaze - Shake the container and apply 3 coats. Start with the inside first. Wait for glaze to dry before applying the next layer. Apply the layers informally to prevent "spotty" look end results. Clean the bottom of your piece. It should be free of glaze 1/4" from the bottom. Read all notes for the specific glazes before applying (e.g., some move so much and cannot be used on the outside surfaces of a pot). Matte or crackled glazes are not recommended for use on food containers (can build up bacteria and may be hard to clean).

c. Under glaze is generally used for detail painting, though it can be used to cover the entire piece if you so desire. Paint flowing coats of under glaze on your piece, being careful of brushstrokes which could show up after the firing. After painting your detail on the piece you should sponge or lightly brush on the first coat of clear glaze, then paint on two more coats, being careful not to smear your detail paint. Wait for the under glaze or clear glaze to dry before applying the next layer. Clean the bottom of your piece. Under glazes are not considered to be safe for dinnerware until they are sealed with clear glaze.

Glazing a Small Pot Using Glazing Tongs

	Fig 1. Grip the pot firmly between the prongs of the tongs. It is important that the grip is not only secure but will enable you to manipulate the pot in the glaze container. Practice the movements needed in the air before actually dipping the pot in the glaze.
	Fig 2. Lower the pot into the glaze with the rim tilted slightly upward. This will prevent air being trapped in the pot if the neck is narrower that the rest of the pot.
	Fig 3. With a smooth rapid action push the pot down into the glaze.
	Fig 4. Hold the pot submerged long enough to build up the required layer of glaze.
	Fig 5. Remove the pot smoothly from the glaze, tilting the bottom of the pot upward to allow the glaze to run out of the pot as it is lifted.
	Fig 6. Hold the pot over the glaze container with the bottom tilted upward to allow the surplus glaze to collect at the rim and drop into the container. Gently shake off the last drop from the rim (or touch it with a small soft brush already wetted with glaze) and place the pot on a suitable stilt to dry.

Glazing a Small Pot by Pouring and Dipping

	Fig 1. The glaze is poured into the pot. The glaze is less likely to dribble over the outside of the pot if it is filled to not much above half way, although this does depend on the shape of the pot and the edge.
	Fig 2. The pot is tilted and rotated as the glaze is poured out, making sure the whole of the inside is coated. Tilting and emptying begins as soon as the glaze has been poured in. The aim is to end up with an even coat of glaze with a neat edge and no glaze on the outside. The pot is left for the short time it takes for the glaze to become touch dry.
	Fig 3. As soon as the inside is touch dry, the edge is dipped into the glaze to a depth of about half an inch.
	Fig 4. The pot is then put down immediately and picked up by the dry part of the inside using firm pressure of the finger tips, avoiding touching the wet rim.
	Fig 5. The pot is pushed into the glaze to slightly overlap the dipped edge. Ideally the top edge should still be wet when the main outside dip is carried out so that there is no obvious thickening of the glaze at the overlap. The pot is held in the glaze long enough for an adequate thickness of glaze to form and is then lifted out and placed on a suitable stilt to dry.