Matte Crystalline Glaze: Focus - Mondre & Manz 4067 Frit
The first time I saw a matte crystalline glaze was on a piece by Hein Severijns. Both the bottle and the glaze recipe were spotlighted in the book, “Smashing Glazes”, by Professor Susan Peterson. Neither the recipe, nor the corresponding firing schedule looked easy.
It was only a short time later, when John Tilton’s crystalline mattes caught my eye.
Tilton has told me many times how troublesome these glazes are to produce (refer to the relevant Clay Times Article), but those that come out well are extraordinary.
In 2006, while preparing for the Peter Ilsley Workshop, Ilsley referred to the glaze developed by Peter Fröhlich. The glaze recipe is listed in Ilsley’s book, “Macro-Crystalline Glazes”:
Matt - 1260°C
Frit 4067 : 77
Feldspar Potash: 21
Zinc Oxide: 16
Lead bisilicate: 11
Flint: 7
Rutile: 8
The 4067 frit is manufactured by Mondre & Manz in Germany. It is only one of the frits that host Kris Friedrich had shipped in for the Ilsley Workshop.
At the workshop, John Tilton, Marsha Silverman, and Mark & Scott Winner focused on developing Fröhlich’s recipe, with good success.
The chemical formula for MM 4067 is:
K2O: 4.60
ZnO: 12.00
BaO: 37.80
Pb2O3: 11.00
Al2O3: 5.00
SiO2: 29.60
Although MM frit 4067 is not available in North America, a number of people are still experimenting, either by using the frit directly or by substitution. Chris Cantello has discussed some ideas on this site (see the comments section at the bottom of the Ilsley workshop page).
Andreas Widhalm created a frit replacement through a computer program he developed, employing the Seger Method:
Potash Feldspar: 24.411
Lead Mono-silicate: 12.649
Zinc Oxide (Calcined): 10.917
Barium Carbonate: 43.947
325 mesh Silica: 8.077
Bill Campbell has been firing some gorgeous matte crystallines. It employs neither the MM 4067, nor the additional Lead component called for in Fröhlich’s matte recipe.
As for myself, I am working with a glaze (and a process) that doesn’t rely on lead or the German frit as well.
This matte/satin-matte effect is achieved by a combination of chemically altering the base glaze, putting it through a standard crystalline firing, and then re-firing it to just below it’s melting point. It’s tricky, as firing it even a bit hotter than necessary will cause the glaze to soften too much and produce a blistered surface. Glazes fired in this way without the chemical modifications may provide a similar effect, but the loss rate is higher, due to an even smaller heatwork window. A piece must often be put through several firings before it yields the right surface –but once it blisters, it’s ruined.
Needless to say, at this point I’m doing very few of these.
Hi Jesse: This is the glaze that I am testing now to match the M&M glaze from the workshop.
M&M Glaze match {Cantello}
Custer ’spar 15.4
Barium carb. 33.3
Zinc ox. 15.3
Lead monosilicate 20.3
Silica 8.3
Pearl ash 2.9
Glo-max kaolin 4.5
Add:
Rutile .6
Copper carb. .1
Chemical Analysis:
Na20 .02 Al203 .09 Si02 .88
K20 .08 Ti02 .14
Zn0 .39 Fe203 .01
Ba0 .35
Pb0 .15
Cu .02
I fire 275F/hr to 2385F, hold 12min.
It came out a very nice soft satin matte pale lime green color. It had very few and very small crystals on top of the form. My thought is that I over-fired this glaze by about three cones. It’s my guess this glaze should be fired in the cone ^9 range. Anyone care to test? Jesse?
Did Bill give a temp with his glaze ?
___________________________________________
Jesse Hull says:
Chris,
Ramping 275F/hr, with a hold of 12min at 2385F equates to an Orton ^11.
As per a test at ^9, I rarely fire below ^10.5 any more. I may try it –however the only lead I currently have is either in the Bisilicate or Borosilicate forms. Lead (Mono)Silicate is roughly 85% PbO & 15% SiO2. I wouldn’t want to throw Boron into the mix, and the Bisilicate form has 35% SiO2… easily enough to throw the test off without being recalculated.
Bill Campbell doesn’t offer much when it comes to his matte recipe.
I first saw some fine examples in 2006. I had been asked to organize images and send them to Antonio Vivas when Diane Creber’s article was being submitted to Revista Ceramica. Bill sent me some pics for the article, and told me that the formula didn’t include the MM frit or Lead.
All I know from conversations and visits to his facility is that the glazes are gorgeous and fairly consistent.
~jesse.
Comment by chris cantello — March 16, 2008 @ 9:54 am
I was here…
I will send your URL to Smart
Comment by Edouard Bastarache — March 16, 2008 @ 5:30 pm
Thanks Edouard-
~jesse.
Comment by Jesse Hull — March 16, 2008 @ 7:34 pm
M&M Glaze copy 2 no lead {Cantello}
Custer feldspar 11
Kona F-4 feldspar 19
Barium carbonate 38
Zinc oxide 18
Silica 6
Talc 8
Add:
Rutile 7
Copper carbonate 1
Chemical Analysis:
Na2O 0.05 Al2O3 0.10 SiO2 0.93
K2O 0.04 TiO2 0.14
MgO 0.11 Fe2O3 0.01
CaO 0.03
MnO 0.00
CuO 0.01
ZnO 0.40
BaO 0.35
Alumina:Silica ratio is 1.00:9.21
Neutral:Acid ratio is 1.00:10.72
Alk:Neut:Acid ratio is 1.00:0.10:1.08
Expansion: 96.5 x 10e-7 per degree C
Comment by chris cantello — March 16, 2008 @ 8:19 pm
Hi Jesse,
I have an article about refired matt crystalline glazes in Ceramics Review 198 nov-dec 2002.
It is sorry the pictures numbering is made wrong, and there are some failure in the recipes too.
The pictures numbers are correctly from left to right :
6,5,4,7,8,9,1,2,3
K2196 fritt: 72 % BaO + 28 % SiO2
The amount of Quartz in my recipe is 24 g not 2.24 g !
Now I have matt crystalline glazes made with Ba fritt too. ( No any PbO in the recipe )
Ferenc Halmos
Comment by Ferenc Halmos — October 27, 2009 @ 9:22 am