Cone 6 Glaze Testing & Reporting


Cone 6 Glaze Testing & Reporting

Collaborate on building an online list of well documented glaze recipes, with application and firing methods. Strong photo documentation. Only glazes that are mature at cone 6 will be included.

Testing the glazes, and identifying their problems and fixing them. Also, if there are obvious issues just by looking at a glaze recipe (like high barium, insufficient clay to suspend or harden, too much feldspar (which causes crazing), too much clay (causing crawling, peeling), hard-to-get materials, non-specific materials, etc) then it needs to be fixed as part of the testing I would say.

Tony Hansen included links below to procedures for a few glaze tests that could be done. Another good one would be to appraise the rate at which it settles, how hard is the dry layer, the water content of the slurry, the viscosity, these could be measured with commonly available tools.


Thermal shock test

Melt flow test

Glaze hardness test

Glaze leaching test

Members: 131
Latest Activity: Jan 30, 2022


Discussion Forum

Waterfall Brown with a typo.....

Started by Gina Skillings Feb 23, 2018. 0 Replies

I'm setting up my new studio, mixing some glazes and get my first glazes unloaded. I was shocked at the Waterfall Brown as it wasn't anything like it had always been and I hadn't bought new…Continue

Tags: Brown, Waterfall

A few hundred glaze recipes for Ye"all

Started by Lawrence Weathers. Last reply by Lawrence Weathers Jun 21, 2017. 3 Replies

I found that I had a 2013 glazechem database.There are hundreds of recipes. I extracted the recipes for you folk. The files were so large that this software would not accept even one of them as…Continue

What causes glazes to react with each other

Started by Brent Farler. Last reply by Brent Farler May 18, 2017. 4 Replies

I have noticed that glazes often tend to either react when layered or are quite stable and do not mix.  If anyone has any insights into the chemical reactions I would like hear.  It seems like there…Continue

Ian Currie Grid Glaze Test Method

Started by Joseph Fireborn. Last reply by Joseph Fireborn Jun 6, 2016. 3 Replies

This is the place for all things Ian Currie Grid Test Method.Feel free to post:1. Questions2. Tiles you have made and interesting things you discovered3. Alternate methods4. Anything related to this…Continue

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Comment by Lawrence Weathers on January 28, 2017 at 10:48am

I have the GlazeChem database from about 2013. Tony says that I can upload it to Insightlive. Do you folks want me to do that via C6P.

I have no idea what's in it since I don't have GlazeChem.

Comment by Tom Anderson on July 24, 2016 at 3:24pm

Hi George:

I read through the posts/comments in this section, hopefully I did not miss any of them. The testing parameters shown are certainly welcomed and should be used by those mixing their own glazes.

From some of the comments, I also noticed there was no discussion on glaze formulation criteria: unity formula, formula limits, and acid index. From the post on  the currie grid test: the SI/AL topic has not come up either. Everyone has their  own priorities for glaze mixing: for me it is SI/AL. Although I focus on crystalline glaze, I have spent a fair amount of time researching these glaze fundamentals.

Also looked through the glaze recipe you referenced: as a rule of thumb any time I see a recipe with more than 70% flux I automatically check the COE. Even more so when sodium and potassium are the primary fluxes.

Seeing as though this is a cone 6 dedicated site: I think it is important for members to know what fluxes are doing at this temp. Sodium and potassium are in a gaseous state at 2232F. Lithium, magnesium, calcium, and strontium are in a liquid state at this same temp. I am sure everyone has noticed that pin-holing almost always occurs when sodium and potassium are the primary fluxes in glaze; and in some cases the clay. Obviously there are many parameters governing this problem; but recipes with Na or K should always be suspect for the reasons stated.

Tom Anderson

Comment by Joseph Fireborn on June 6, 2016 at 7:57am

I created the currie discussion board, lets move all future chat there. 

Comment by Joseph Fireborn on June 6, 2016 at 7:52am


Neat ideas. I will start a currie thread as I don't want to get confused either with this being the discussions for general group. I am excited that so many people have done the currie method on cone6pots. Cause I haven't tried it yet as my mold is drying but I am excited. I have got to order some volumetric cylinders and find some cups to use for mixing.

Comment by Bill Schannen on June 6, 2016 at 6:11am


I am new to this and have not figured out how to see the whole thread so pardon me if this is redundant or ends up on the wrong thread.

I have done several Currie tests. Two thoughts:

1. Test tiles. I use a plywood form to make my tiles. The raised ridges can be formed by cuts into the surface. I use WD 40 as the release. I use a rubber mallet to press the form into my slab. Bisque takes care of any oil residue.

2. The Currie method uses equal volumes of the 4 base glazes and mixes by volume. An alternative I used was equal weights. Add approximately 100 gms (ml) of water to each 100gms of base batch. Vary as necessary; some glazes need more, some less.

You can then do the individual tile mixtures by weight using the same ratios as the volume method. I use little plastic bathroom cups with numbers on them, a balance and I dispense the mixtures from squeeze bottles. With a little practice this can be very quick. Don’t be afraid to toss whoopses and redo if necessary.

Comment by Joseph Fireborn on June 5, 2016 at 6:19am


Yea my tile squares are 1.25 inches x 1.25inches. The picture might not look like it, but I am hoping after shrinking they are close to 1 inch. 

Comment by John McClure on June 4, 2016 at 8:16pm

not fold but form

Comment by John McClure on June 4, 2016 at 8:13pm

Joseph Fireborn, I see you are making a fold to press test tiles, just remember you will have the form shrink when you bisque fire and then your test tiles will also shrink. So you may want to check on the size of the mold form.  It is great fun to work on the grid for testing. I also found it easier to mark the bisque form with letters and numbers for making test tiles. John

Comment by Joseph Fireborn on June 4, 2016 at 7:39pm

Gearing up to start doing currie grid test! Working on a celadon for porcelain, and a black matte to go with it.

Anyone else on here conduct currie test?

Comment by Kabe Burleson on September 1, 2014 at 6:29pm

Question? I have the book "The Glaze Book" by Stephen Murfitt. Nice book ,great photos. The recipes seem to jump from cone 05 to cone 9/10 with very few cone 6 recipes in between . Has any one tried to modify any of the higher temp glazes to put them in the cone 6 range? I know it can take more than just upping the flux. Just wondered if anyone has tried or if the rest of you just know better. Happy Firing


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