Transparent Cone 6 Whiteware Glaze
For Whitewares, Porcelains. Plainsman code G2926B.
Intended for use on M370. It has the lower thermal expansion necessary to fit (without crazing). It sources boron from a frit instead of troublesome Gerstley Borate (you need to see and use this side-by-side with a Gerstley Borate based glaze to appreciate how much better this is). This recipe has good suspension and very good application properties if it is the correct consistency (in our studio about 1.45 specific gravity, this is about 45% water or 2.04 kg of water for each 2.5 kg bag of premixed glaze). If the specific gravity is too high it may settle out.
G2926B Whiteware transparent with various stain additions on a porcelain body. It does not work as well as the G2916F Transparent for chrome-tin stains.
To prepare the transparent glaze for use, adjust the amount of water so you have a specific gravity of 1.45 (see link below). Then add vinegar (if needed) to gel it. You can tell if it is gelled by stirring and then stopping and watching it. It should continue moving for a few seconds, then stop and bounce back slightly (that bounce back is called the thixotropy). For a gallon of glaze it might take 5 cap fulls of vinegar, but stir after each one to see if there is an effect (be careful not to put too much). When it is right you will be able to dip a piece for 1-2 seconds, withdraw it and get an even layer without dripping. Adjust your bisque temperature to get more porosity (if the glaze dries to slow) or less (if it dries too fast).
Still getting crazing, perhaps on P300? Check G3838A.
Screening: We have not ball milled this product, thus it may contain some oversize particles from the constituent materials. We advise sieving the glaze slurry to at least 80 mesh.
The recipe of this glaze is not proprietary. We developed it and sell it premixed but if you want to batch it yourself, please feel free to do so. For more detailed information at the Digitalfire Reference Library (e.g. the recipe, mixing your own, more pictures) click here. The mechanism of the recipe is explained, this may empower you to adjust it to you needs.
Adding the Stains and Opacifiers: Simply multiply the weight of the amount of powder you want to use and divide by 100. For example, if you have 2000 grams of glaze powder and want to add 6% stain: 2000*6/100=120 grams of stain. Or, 10% zircopax: 2000*10/100=200 grams of zircopax. The percentages of stain shown are suggestions. For some colors you may need to use more, others less (your fired results will demonstrate if the glaze is too dark or too light for your liking). If you are glazing a dark-burning body, consider applying a white engobe to areas where you want bright colors. For functional surfaces that you want to be white, consider applying a white engobe to the inside of the ware (at the leather hard stage) and using a transparent, this will give a much cleaner and more homogeneous surface than (white glazes do not cover well over a dark bodyies). If you are new to the use of engobes and fire cone 6, consider starting with this one.
Underglazes with M370 and G2926B transparent. The colors were airbrushed and the clear glaze was sprayed over top.
Safety Data SheetClick here for web view.
|Plainsman Clays Ltd.|
702 Wood Street, Medicine Hat, Alberta T1A 1E9
Phone: 403-527-8535 FAX:403-527-7508