Question:

How do I decorate my ware?

Once-fire glaze

An addition of about 8% bentonite will easily convert a conventional glaze into a once-fire glaze.

Glaze Selection

As we become better at making beautiful forms we don't necessarily become better at achieving great glaze results. It seems so unfair! If you are serious about achieving great results your first step is to begin your own glaze journal today. It's important to do many different things right before you can be successful at glazing. First, consider what textures and colors you want the glaze to contribute to your finished form. Many art centers and community labs have test tiles you can observe before you commit to glazing with them. (If you are at a home studio, you will want to create your own test tile pattern with some of your favorite glazes.) We recommend you test one coat or two to see if it runs or changes colors when applied thicker. Also, test glazes on different clay bodies. If your facility has tiles, they probably indicate which glazes are stable and which glazes run. Glazes that run are not suitable for the outside of a piece. A glaze that runs can run off the pot and onto the kiln shelf making a huge mess. The same glaze can look very different on various clay bodies. Also, it may look different when applied thin vs. thick. An example is a copper red glaze called Oxblood, it's white when applied thin, red when applied thick - quite a difference.
The next step is choosing a suitable glaze for your clay body.

Recipe: Semi matt dark blue

Crystal glazes: Semi matt dark blue
A glaze with zinc. You must not apply it too thick. 1260-1280oC with one hour at the top temperature. Does not need a slow cooling. Small or no crystals.
potash feldspar NR 65,90
dolomite 16,15
zinc oxide 17,95
red ferric oxide 5,00
cobalt oxide 2,00

Handy glaze pourer

Handy Glaze Pourer: The green straight handled cups that come with dry
detergent can have the
handle bent straight down by heating over a flame. They then will hang over
the edge of your glaze
bucket, and they pour a nice small stream from the corners of the cup.

Grinding pots

Sharpening stones can be put to great effect by using them to grind off by hand left over bits of grog or alumina on the feet of pots and bowls or other surfaces.

Access to a kiln

The glazes will be fired, and thus permanent. But that means you need access to a kiln. One place to check is with contemporary ceramics studios. Often they will fire your own pieces for a fee. Another is to check the Kiln Time-sharing listings at BigCeramicStore.com. There may be a potter in your area who will sell you space in their kiln. Another approach would be to enrol in a community class that has a kiln. And finally, you can buy your own kiln. A small kiln can be had for only a few hundred dollars, and is much more convenient that trying to find space elsewhere. You also have the benefit of total control over the process, so someone else doesn't smudge your design, or drop your piece, for example. These small kilns plug into normal household power, and if you upgrade to a larger kiln later they can be used as test kilns to test glazes.

How to make a test seive

Test Sieve:
A small test seive is a must, for experimenting with glazes and oxides.
They are very easy to make and become invaluable.
Purchase a strong plastic container approx 1 ltr capacity. with a rim
on the base, the rim gives the sieve strength. Also purchase 200 mesh wire, it is expensive but only a tiny circle is required.
cut around the rim with a stanley knife, heat a long handled knife in an
open flame (a gas kiln is great), and gently melt the plastic around the
hole and stick the mesh to the molton plastic.
This technique can be used on a bucket seive as well for large batches
of glaze.

Alkalis

What are Alkalis?
Alkalis are the opposite of acids, potters call the glaze and body fluxes their alkalis. These are the non-colouring metal oxides which react with the acids in the presence of heat to produce silicates(glasses).
The so-called strong alkalis are:
Lithium oxide
Sodium oxide
Potassium oxide
Which are soluble in water. The weaker alkalis are partly referred to as aldaline earths or by the more general name of bases. They are:
Beryllium oxide
Magnesium oxide
Calcium oxide
Strontium oxide
Barium oxide
Zinc oxide
Cadmium oxide
Lead oxide
Bismuth oxide
They are not necessarily weaker in ceramic fusions but are less actively soluble in water.
They do not give the same bright colour response in glazes as the strong alkalis.
Alkalis release negatively-charged hydroxyl ions when dissolved in water. They have a sting and a re corrosive in a similar way to acids whilst being neutralized by the substances they meet. The soluble alkalis, soda ash and sodium silicate, are used to deflocculate clay for slip casting.

Crackle glazes: varieties

Crackle glazes are available in a variety of colours and may be in matte, gloss or transparent varieties.

Semi matt cobalt green with yellow crystals

Crystal Glaze: Semi matt cobalt green with yellow crystals.
This glaze use to be very safe. It is a green semi matt glaze with more or less bright yellow crystals. 1270oC with one hour at top temperature. Not too thick.
nepheline syenite 66,05
zinc oxide 4,82
dolomite 4,51
whiting 4,82
ball clay 4,51
quarts 6,91
rutile 8,41
copper oxide 0,30
cobalt oxide 2,00
red ferric oxide 0,60

Liquid Glazes: commercial

Commercial Liquid Glazes: You can purchase commercial glazes and underglazes in liquid form, which are usually formulated for brushing. All you need to apply the glaze is a brush. Some glazes are difficult to brush on smoothly, you will see brush marks. Others will melt enough to erase the brush marks.

Ashes in ceramics

What are Ashes in ceramics?

Ashes are the noncombustible remains of animal (bone) and vegetable matter used by the potter as a source of body and glaze fluxes. The commonest uses are of bone ash in bone china body and vegetable and wood ashes in stoneware ash glazes.
The ashes provide fluxing and other oxides. The main oxides involved are those of calcium, phosphorus, potassium, sodium and aluminium with silica and many trace oxides. Although the original matter is organic (that is, with carbon being the most important element and hydrogen,
Nitrogen and sulfur also involved) the potter is seeking the inorganic content. Thus from a large bulk of wood the potter collects a relatively small amount of ash.

The ash needs to be washed well to remove all unwanted compounds and firing takes care of the rest.

Dry Glazing description

Dry glazing: In the context of single firing, dry glazing is the practice of applying glaze to dry, unfired ware.

To prevent glazes from settling

To prevent glazes from settling rock hard, add a small amount of Epsom Salts (Magnesium Sulfate) to the glaze. Depending on the glaze composition, it may hardly settle at all, or if it does, be easily stirred again.