Glaze Mixes

[Wilboy64]

I am new to mixing glazes and wonder if the formulas I am looking at on most web posting include a base glaze formula with the colorant added to make a complete mixed glaze or if the formula must be mixed and added to a base glaze ? This is an example I copied from Central Clay,

Shino cone 9 to 12 (ox. & red.)

F4 feldspar-15

Spodumene-13

Soda ash-3

Nepheline syenite-50

Ball clay-16

EPK-3

 

 

Help please give me the right direction to follow........ New but trying hard to get it right.

[Marcia Selsor]

Not sure what your question is. The recipe you present doesn't have an addition of a colorant.

 

Shino cone 9 to 12 (ox. & red.)

F4 feldspar- 15

Spodumene- 13

Soda ash- 3

Nepheline syenite- 50

Ball clay- 16

EPK 3

Total 100

You should find most bases add up to 100 per cent.

Then colorants such as copper, iron, cobalt, manganese rutile, nickel, are the more common colorants. Tin is added as an opacifier.

If a recipe calls for 0.5% cobalt carbonate, that would be 1/2% or .5 grams to 100 grams. 2% of a colorant such as Rutile, would be 2 grams of weight. To mix a !000 gram container would require multiplying everything by 10. A 5 gallon bucket can hold 9000 to over 10,000 grams depending on the density of the ingredients. Wood Ash is not dense but fluffy. A five gallon bucket of wood ash would be more like 6000-7000 grams maybe.

I hop this helps. Try to read more about glazes. Take a class or workshop from someone like John Britt or Ian Curry. Follow more discussion on this forum regarding glazes.

Hope this helps.

Marcia

[Marcia Selsor]

Another great help in understanding Glazes , is Mastering Cone 6 Glazes by John Hesselberth and Ron Roy. There is also glaze soft ware that accompanies this book.

There are many glaze software programs where you can manipulate formulas for different temperature, chemicals, etc.

Look into some of these ideas.

 

Marcia

[Wilboy64]

Another great help in understanding Glazes , is Mastering Cone 6 Glazes by John Hesselberth and Ron Roy. There is also glaze soft ware that accompanies this book.

There are many glaze software programs where you can manipulate formulas for different temperature, chemicals, etc.

Look into some of these ideas.

 

Marcia

 

 

 

Thanks Marcia, I am reading more and have the books you suggested. Do I understand that the formula I listed would be considered a base formula and I would add the color to it?

[Marcia Selsor]

This is a Shino glaze. I believe it doesn't need a colorant. You would add colorants to Iron Saturates, or semi matt glaze bases. A clear glaze would not need a colorant.

As "gold" glaze would call for a low percentage of iron or rutile. A copper red would use a small percentage of copper and tin. A green glaze might require a certain type base i.e. soda or potash and maybe 4% iron. There are infinite variations. Most recipes you will find will have a base amount of 100 to which the colorants are mentioned in percentages. Example, here is a link to Alisa Clausen's glaze testing site. She is an avid glaze tester and posts results and insights.

http://www.alisapots.dk/glaze.htm

She works in Denmark, so some of her chemicals are not used in the US.

Another example is one of my favorite glazes. Nice functional glaze. These colorants were for reduction at ^6.

 

 

This one is 99.5. Just use as if 100 when figuring percentages.

 

Marcia Selsor’s ^6 Reduction Semi Matt

 

EPK 20

 

Dolomite 17.5

 

Neph. Syen. 33.5

 

Silica 16

 

Whiting 3.5

 

Ger, Borate 9

 

99.5

 

Takes colors well

 

Blue/lavender 1% cobalt Carb

 

Light green 1.5% Nickel Carb

 

1.5% Rutile

 

Lt. Blue gray .5% cobalt carb.

 

2.5% rutile

 

gray 2.5 rutile +2.5 nickel carb.

 

 

 

 

 

Marcia

[Pres]

I am new to mixing glazes and wonder if the formulas I am looking at on most web posting include a base glaze formula with the colorant added to make a complete mixed glaze or if the formula must be mixed and added to a base glaze ? This is an example I copied from Central Clay,

Shino cone 9 to 12 (ox. & red.)

F4 feldspar-15

Spodumene-13

Soda ash-3

Nepheline syenite-50

Ball clay-16

EPK-3

 

 

Help please give me the right direction to follow........ New but trying hard to get it right.

 

 

This Unity formula is a starting place. I usually put this formula into a spread sheet format with multipliers for each of the materials and a total for the batch. Lets say you wanted to have 1000 grams of glaze. multiply each of the materials by 10 in the spread sheet. Set it up so that totals to 1000. below that total add in any coloring agents included in the unity formula so that they are not included in the 100%. They would also get multiplied by 10. Once the glaze is set up, you can copy and paste the section to other fields to include multiple glazes. I have put all of my glazes in this type of set up, and then all I have to do is change the multiplier to change the size of the batch.

[Guest JBaymore]

This Unity formula is a starting place.

 

 

Purely in the sake of keeping this newer person accurately on track, the listing that has been given is not a "formula" of any kind, it is a "recipe". A formula is the after-firing chemical composition of the glaze expressed in the relationships of the number of moles of the various oxide components to each other, and in that case is often called a "Seger Formula". This is because the most common way of looking at glazes was developed by Herman Seger. When this formula has the sum total of all of the fluxing agents expressed in a format adding up to "1", it is a "Unity Formula". A recipe is raw materials based. A formula is chemistry based.

 

When a recipe adds up to 100 parts, you can say it is a "Percentage Recipe", meaning you can easily use it directly to change the batch size that you might want to mix. Recipes are what you weigh out in the glaze lab.

 

Sometimes accurate terminology is important to developing a solid understanding. Hope this helps to keep things clear.

 

best,

 

....................john

[Marcia Selsor]

This Unity formula is a starting place.

 

 

Purely in the sake of keeping this newer person accurately on track, the listing that has been given is not a "formula" of any kind, it is a "recipe". A formula is the after-firing chemical composition of the glaze expressed in the relationships of the number of moles of the various oxide components to each other, and in that case is often called a "Seger Formula". This is because the most common way of looking at glazes was developed by Herman Seger. When this formula has the sum total of all of the fluxing agents expressed in a format adding up to "1", it is a "Unity Formula". A recipe is raw materials based. A formula is chemistry based.

 

When a recipe adds up to 100 parts, you can say it is a "Percentage Recipe", meaning you can easily use it directly to change the batch size that you might want to mix. Recipes are what you weigh out in the glaze lab.

 

Sometimes accurate terminology is important to developing a solid understanding. Hope this helps to keep things clear.

 

best,

 

....................john

 

 

Yes, that is how I understand unity formulas versus percentage recipes. Two different animals.

Marcia

 

 

[Pres]

This Unity formula is a starting place.

 

 

Purely in the sake of keeping this newer person accurately on track, the listing that has been given is not a "formula" of any kind, it is a "recipe". A formula is the after-firing chemical composition of the glaze expressed in the relationships of the number of moles of the various oxide components to each other, and in that case is often called a "Seger Formula". This is because the most common way of looking at glazes was developed by Herman Seger. When this formula has the sum total of all of the fluxing agents expressed in a format adding up to "1", it is a "Unity Formula". A recipe is raw materials based. A formula is chemistry based.

 

When a recipe adds up to 100 parts, you can say it is a "Percentage Recipe", meaning you can easily use it directly to change the batch size that you might want to mix. Recipes are what you weigh out in the glaze lab.

 

Sometimes accurate terminology is important to developing a solid understanding. Hope this helps to keep things clear.

 

best,

 

....................john

 

 

I stand corrected, I know the difference, but. . . .