Are Gerstley borate and Gillespie borate the same?

In the fired state, Gillespie borate is virtually identical to Gerstley borate by virtue of the chemical match of oxide content. The special behavior of Gerstley and Gillespie borates that produces the unusual glaze effects results from two mechanisms: immiscibility and solubility.

What is Gerstley borate in glaze?

GERSTLEY BORATE (real) A sodium-calcium-borate compound used as a low and mid-range glaze flux. This is a conglomerate mineral made up primarily of Colemanite, Ulexite and Hectorite. Gerstley is a natural borate similar to but not interchangeable with Colemanite on a 1 to 1 basis.

Where does Gerstley borate come from?

Gerstley borate is named after James Gerstley, former managing director of Borax Consolidated Ltd. It is manufactured by U.S. Borax and Chemical Corp.; the mine is located near Death Valley, CA. G.B. is an inexpensive source of B2O3 and CaO in glazes. It is often used in place of colemanite.

Is Gerstley borate a clay?

Thus it is common to find Gerstley-Borate-based recipes having no clay content. GB natural source of boron that was mined in southern California for many years. Mineralogically it is a combination of colemanite, ulexite and high plasticity clay (likely hectorite).

What can I use instead of calcium borate frit?

American substitute: Gerstley Borate.

Help for Long-time Gerstley Borate Sufferers!

What is a substitute for Gerstley borate?

IMCO Borate is a blended product that is a direct substitute for Gerstley Borate. They say it "has the same physical properties as Gerstley Borate.

What is Gillespie borate?

Gillespie Borate™ is a blended borate mineral for use in glaze formulas replacing Gerstley Borate on a pound for pound basis. Gillespie borate was developed through a careful formulation process that has resulted in a virtual chemical match to Gerstely borate. Gillespie Borate is a mixture of ulexite (Na2O. 2CaO.

What is Gerstley borate used for?

Gerstley Borate is a sodium-calcium-borate compound used in ceramics as a low and mid-range temperature flux. It is essentially a source of boron in glazes, and acts as a melting agent. It also can act somewhat as an opacifier and prevent crazing.

What is Laguna borate?

A specially formulated flux containing a high percentage of boron. This material mimics the fluxing characteristics of Gerstley Borate.

What is Custer Feldspar?

Custer Feldspar (NaKO. Al2O3. 6SiO2 ) is a one of the primary feldspars used in ceramics. It is used in both clay (up to 25%) and glaze (up to 100%) formulas and is made up of silica and alumina combined with sodium and potassium oxides. Feldspar custer is mined in Custer, South Dakota.

What is EPK kaolin?

EPK (Kaolin)

Edgar Plastic Kaolin - is one of the most popular kaolins used in glazes for its suspening capability, EPK is a water washed kaolin mined in Edgar Florida. It is fairly plastic and very white firing compared with most other American kaolins.

What is the difference between frit 3124 and 3134?

Fortunately, these frits are similar. Except for one thing: Frit 3134 has almost no Al2O3 (3124 has lots) and significantly less SiO2. That is a game changer, making it melt dramatically more and lower. Not surprisingly then, her glaze melted way too much, running off the ware.

What does Zircopax do in a glaze?

Zircopax affects glaze melt viscosity, surface smoothness, thermal expansion and color development and can be implicated in a range of glazes faults associated with these.

What is whiting in ceramic glaze?

Whiting- Calcium Carbonate – CaCO₃ (m.p. 4650^o F/2570^o C) is a finely ground powder composed essentially of pure Calcium Carbonate derived from Limestone, Chalk, or Marble. It is the most common source of Calcium in a glaze and clay body.

How do you make calcium borate?

It can be prepared by reacting calcium metal with boric acid. The resulting precipitate is calcium borate. A hydrated form occurs naturally as the minerals colemanite, nobleite and priceite. Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Where is Ulexite found?

It is found principally in California and Nevada, US; Tarapacá Region in Chile, and Kazakhstan. Ulexite is also found in a vein-like bedding habit composed of closely packed fibrous crystals. Ulexite is also known as TV rock due to its unusual optical characteristics.

What is the formula of Colemanite?

Colemanite | B4CaO7 - PubChem.

What is a frit in pottery?

A frit is a type of ceramic glass. It is a combination of materials that, when melted together, are rendered insoluble and resistant to acid attack. They are, therefore, a means of introducing certain materials into a glaze which would otherwise be toxic.

Is Minspar a soda feldspar?

FELDSPAR MINSPAR 200 (Soda) is a soda feldspar used in glazes and clay bodies if a soda flux is wanted. 2010 - now the substitute for Kona F-4, which is no longer being mined.

What is Cornwall stone?

Cornwall stone is a low iron feldspar material used primarily as a flux in clay bodies and glazes. It has a more diversified selection of fluxes than other feldspars but also has one of the highest silica contents.

What is the difference between Zircopax and Zircopax plus?

The designation 'Plus' refers to the particle size, it is a finer grained version zirconium silicate (also known as Superpax). This material is a more potent opacifier than Zircopax, testing will be required to determine how much less to use when substituting.

Is Zircopax the same as Superpax?

Zircopax is a brand name of zirconium silicate (or zircon). It is primarily used in ceramics to opacify glazes. In North America, the most popular zirconium opacifiers fall under the brand names of Zircopax Plus, Superpax, Zircosil and Excelopax.

Is Ultrox the same as Zircopax?

Ultrox is zirconium silicate, thus the same as Zircopax Plus or Superpax.