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Zero3 L & H Glaze Variants

Description

G2931L is a low expansion adjustment to the Zero3 K Glaze to make it fit Buffstone and Terrastone (without crazing). G2931H is a high expansion adjustment for fit high talc bodies (like L213, L212).

Firing

To get the best defect-free surface please consider using a hold-rise-drop-hold firing schedule (you can find more information about it on this page).

Terrastone with Zero3 L glaze fired at cone 03.

Glazing

We recommend decorating ware using underglazes, then overglazing with this and firing to cone 03. You can fire to 04 but ware will not be as strong and the glaze not melt as well.

If the specific gravity is around 1.43 and it is gelled enough it applies very evenly with little dripping. Ware needs to be absorbent. If your ware is thin it might be necessary to glaze the inside and outside in separate operations (with drying time in between).

Recipe

As of June 2017 these are not yet available as a premixed products. But you can mix (and blend) them yourself. For our lab information on the recipes, how to mix and use them click here.

Thermal Expansion

Low fire glazes are much more difficult to match to the body, crazing and shivering are thus much more common that at higher temperatures. That is why we have three recipes: K, L and H. One of these will fit most bodies, if not they can be blended to fine tune fit.

Do not use the Zero3 L glaze on Zero3 stoneware or on talc bodies (like Plainsman L215, L212, L213), it shivers. This is intended, it has the very low thermal expansion needed to fit non-talc, non-vitreous low fire bodies (like Plainsman Terrastone, Buffstone).

Gallery

Buffstone and L215 with underglaze decoration and G2931 clear glazes. But they are not the same. The G2931L glaze (left) has a lower thermal expansion (to prevent crazing on Buffstone). The G2931K glaze fits L215 because the latter contains some talc (which raises its expansion). Both of these mugs have survived a 300F-to-ice-water thermal shock without crazing or shivering. If you switch the glazes the Buffstone mug would craze it and the L215 would shiver it off in flakes.

Buffstone, L212 and L213. Each has its own clear glaze. G2931L, K and H. L is low expansion (for zero talc porous bodies). K is intermediate (for moderate talc bodies like L215 and Zero3 stoneware and porcelain). H is high expansion (for high talc bodies like L212, L213).

Safety Data Sheet

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Logo Plainsman Clays Ltd.
702 Wood Street, Medicine Hat, Alberta T1A 1E9
Phone: 403-527-8535 FAX:403-527-7508
Email: plainsman@telus.net