Gillespie Borate

Note: Currently not available for delivery to Europe, World Zone A, World Zone 2 and World Zone 1.

Description
Health & Safety & Disposal
Customer Reviews

Description

Gillespie Borate also know as Gerstleys Borate, Gillespie Borate is a blended borate mineral for use in glaze formulas replacing Gerstley Borate.

Consistency - Manufactured from high purity refined raw materials, Gillespie Borate™ is highly consistent from batch to batch.
Oxide Match - Virtually identical to Gerstley Borate, this product requires no adjustment to formula and no extra additives are needed.
Mineral Match - Gillespie Borate™ provides the same minerals to the glaze as Gerstley Borate, thus imparting the same glaze activity, texture and effects.
Particle Size Match - As a -200 mesh material, Gillespie Borate™ combines well with other glaze raw materials.
Plasticity Match - A high colloid and clay content gives the plasticity necessary for many applications.
Reduced Glaze Defects - Our laboratory studies indicate that Gillespie Borate™ gives increased glaze surface smoothness and a reduction in crawling and pinhole defects.
Lower In Off-Color Impurities - As a refined blended material, Gillespie Borate™ contains few impurities and produces brighter glazes and colors.

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Health & Safety & Disposal

When handling powdered ceramic materials, you must wear an FFP3/P2 face mask and nitrile gloves to prevent inhalation and skin contact.
Wear a wipeable apron, polyester overalls, or similar. Clean or wash frequently.
Always clean your studio with a wet sponge rather than sweeping to stop dust from becoming airborne.
When preparing glazes, add the dry material to water, not vice-versa, to minimise dust formation.
Do not allow eating and drinking in the studio and thoroughly wash hands when leaving.
Never eat, drink, or apply cosmetics in areas where clay or glazes are handled.
Ensure emergency eye-washing facilities are available in the room.
Review official guidelines regarding studio ventilation and chemical management routinely.

Gillespie Borate is generally safe for short-term studio use, but it contains trace components that pose long-term health risks if inhaled. Because of these hazards, you must handle the raw powder with specific personal protective equipment (PPE) and proper ventilation.

Dispose of as normal industrial waste, in accordance with local/regional/national/international regulations.

Customer Reviews

By Julie Peel on 20th July 2025

"Using the Ceramic Materials Workshop spreadsheet I did find it necessary to adjust the formula for a clear glaze for which I'd previously used Gerstley Borate. See Emmanuel Cooper Potter's Book #140. Neverthless the revised glaze bubbled ie became translucent over black slip and seemed more prone to pinholing and crawling. Glaze used on Audrey Blackman fired to cone 7/8 - as advised in Bath Potters catalogue"