Instructions

1. Determine the size of glaze batch you want to make.

For testing, I recommend a 400 +/- gram batch which is enough to easily dip test tiles into and enough material where you are not dealing with super small portions of material. This fits easily into a 32 oz deli container.

For production use, a bucket for 5,000 – 10,000 grams, depending on size.

2. Calculate on paper how much of each material you will need prior to starting. Double check your numbers. Do not do this on the fly!

To calculate my 400 gram test batch, I am technically going to make it 416 grams. This keeps the math and weighing simple. To do this, everything in the materials and additions needs to be multiplied by 4.

Thus:

Custer Feldspar – 144

Gerstley Borate – 88

Flint – 108

Whiting – 44

Dolomite – 16

Copper Carbonate – 12

Bentonite* – 4

3. Put on your PPE at all times when you are working with glazes and their materials.

*The night before mixing your glaze, weigh the bentonite out and emulsify with water to create a slip. Let this sit overnight to get the full benefits. (Tip from Val Cushing’s Handbook, Notes on Bentonite)

4. Using an accurate gram scale, measure carefully. I zero out my scale in between each material, and also I make sure I get all the material in the bucket. Taking your time will ensure the best results. Make sure to mark off the measurements as you go. Place bowl on scale, zero out scale, measure material, mark off list, dump in bucket, place bowl on scale, zero out scale, measure material, mark off list, dump in bucket…and so on and so forth.

5. Once you have all your material weighed out, use a whisk and mix the materials together.

6. Time to hydrate! Put your water first in a separate bucket. Typically this is about the same volume of materials you have, but err on the side of caution and use less – it is easier to slowly add water than wait for it to evaporate! Add the dry material on top of this and let it sit for about 30 minutes. (For test batches the order isn’t as important, but with production batches, this will help hydrate the material with less effort mixing to get all the dry materials stuck at the bottom.)

7. Hand whisk to incorporate all the material into the water. You can adjust the water if it seems too thick. If it is too thin, you can leave it uncovered for a few days and let it thicken. (Again, it is easier to add more than take it away!)

8. (Optional but Recommended): If you have time, let this sit again overnight to let the materials hydrate.

9. Once everything is incorporated and well hydrated, you will blend the material with a drill mixer bit attachment (production batches) or an emulsion blender (test batches).

10. Time to Sieve! Sieve through a 60 mesh sieve into another bucket. Then take a 80 mesh sieve, and sieve it into the original bucket. Make sure you get all the material through the sieves so that the end result is as consistent as possible. Use the dish scrubber to work the material through quickly!

11. Label your glaze with the name of the glaze and the cone it fires to (Example: Val’s Turquoise, Cone 6). It is a good idea to also keep a glaze journal. Some information to include would be: date, material sources, substitutions or changes, shortcuts (skipping the hydrating processes) – the more information the better!

12. Last, make sure to dip a test tile to test before using in full production. I like to dip it three times; once almost to the bottom of the tile, then 2/3 the way down and then again with just the lip of your tile. This will give you a lot of good information in a small space!