Glaze- glass like minerals, clay and water. A thin coat is applied to bisqueware. After firing, it is permanently bonded

to ceramics.

Glazing

1. Seals your pottery-Otherwise leaky and bacteria can grow in it, hard to clean, frozen water can make ceramics crack.

2. Decorates- many different colors and effects

3. Makes ceramics stronger

Why Glaze?

Glazes change colors when fired – Must look at sample chips to know outcome!

Opaque or Transparent? (know the meaning)Matte or Gloss? (know the meaning)Could your piece be used for food or drink?

Look for this fork and knife symbol . It means it will be safe after firing to eat or drink out of, so it is a “food safe” glaze.

Codes on jar: LG, LM, O, CTL, TP, LT, A- know what they mean!

Selecting a Glaze

Other Symbols on JarAP- (Approved Product) Non Toxic- Safest to use. This does not mean that you will not get sick if you eat it!!

CL (Caution Label) Must be in 7th grade or older to use. Contains chemicals that are dangerous to ingest (swallow), inhale, or have on your skin for a long time. Follow guidelines for safety.

Even food-safe or Glazes are dangerous when inhaled, ingested, or on skin. Long time exposure can cause cancer, liver damage, damages developing fetuses. (in liquid, unfired form)

Even in “Food Safe” glazes…

Causes Brain Damage in people and developing fetuses.

Look for “Lead Free” on the jar. Most should have it.

Lead Poisoning

PWHS tries not to buy glazes with lead, but keep an eye out, we might have some for special applications.

Another reason to read the label!

. Glaze on newspaper. (easier to throw out, than to clean) DO NOT glaze on bare table, boards or cloth.

DO NOT create glaze Dust: Do not flake off dry drips of glaze. Wipe tables well after

glazing with a wet rag.

No Eating, Drinking, Gum chewing, or putting fingers in/near your mouth

when glazes are being used in the room.

Wash hands well. Use care.

Safety Guidelines:

Select color- look at sample chipsUse soft brush(dark bristles better)Dip directly into glaze jar- never pour into cap or another container. Why?

Makes cap hard to close/open-then glaze dries.

Wastes expensive glazeMore to clean up

Keep track of lid- don’t mix upNever mix wet glazes, Use clean brush.

How to glaze at PWHS:

Each coat must dry between coats (5-10 minutes). Will look caulky when dry

Go in different directions for each layer

Never glaze on the bottom of a pot. Leave 1/8” unglazed at bottom edge .

Otherwise it will stick to the kiln shelf / Drip onto the kiln self.

Three Coats of Glaze

Prevent CrawlingWipe or rinse out bisqueware to remove all dust.

Yes you can put it in water, but then it has to dry. No oil on surface -Make sure no greesy fingerprints

are on bisquware No lotion before touchingWash hands after lunch/eating chips, etc. Grease

will keep glaze from sticking.

Consistancy- should be the thickness of latex paint, drinkable yogurt, or heavy cream. Mix with fork. See your teacher before adding water.

Getting Started:

The separation of a glaze coating from the clay body during the firing caused by excessive coats of glaze, or dust /oil on the bisqueware . This results in exposed areas of unglazed or bare clay.

Crawling

Undesirable cracks in the glaze. Caused by excessive coats of glaze or cooling too fast .

Crazing

Keep track of how many coats are applied where. –You or your teacher cannot tell by looking at it later. Write it in your notebook!

Make sure all areas covered with 3 coats. Overlap areas where glaze colors change a little (common mistake – thin or bare spots where colors change)

1-2 coats= streaky, light colors, not shinny, not fully sealed.

Common Mistakes:

Used for inside of a large pot/vessel only. Clear glaze often used- especially if area is

not seen. Get help the first time.

1. Pour in 1-2 cups of glaze (liquidy, not lumpy)2. Twist and roll around3. Roll as you slowly pour out (back into glaze jar so you do not waste it)4. Once is enough, 3 coats not necessary.

Pour and Roll Technique

Large VesselsAlways an optionMust earn “C” or better for privilege to glaze.

Acyrlic Paint and Wax

technique

Layering glaze