Monthly Tech-Tip | No tracking! No ads! |
These mugs are Plainsman H443. The bamboo glaze on the left (A) has 3.5% rutile and 10% Zircopax added to the base G2571A dolomite matte. The one on the right (B) has the same addition but in a base having slightly less MgO and slightly more KNaO. B stains badly (as can be seen from the felt marker residue that could not be removed using lacquer thinner). Why does A stain only slightly? It has an additional 4% Gerstley Borate (GB). GB is a powerful flux that develops the glass better, making the surface more silky. The differences in the recipe provide another advantage: (A) has a lower thermal expansion and is less likely to craze.
Troubles |
Staining of Fired Ceramic Glazes
Ceramic glazes are glass. That means they are always easy to clean, right? Wrong. If the surface is not developed it will be difficult or impossible to clean. |
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Recipes |
GR10-J1 - Ravenscrag Cone 10R Bamboo Matte
Plainsman Cone 10R Ravenscrag Slip based glaze. It can be found among others at http://ravenscrag.com. |
Recipes |
G2571A - Cone 10 Silky Dolomite Matte glaze
A cone 10R dolomite matte having a pleasant silky surface, it does not cutlery mark, stain or craze on common bodies |
Glossary |
Bamboo Glaze
A high temperature reduction glaze made by adding a small amount of iron oxide to a magnesia matte base glaze |
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