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Clear Stiff ^6 Majolica Glaze Please


docweathers

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Dear Doc,

Here is one. But there is no such animal as a Clear majolica. Majolica is opaque . Also colors are added with overglaze on top of the white.

 

 

cone 6 majolica updated thu 31 oct 96   small%20potters%20logo.gif Linda Arbuckle on tue 2 jul 96


Richard Burkett on tue 22 oct 96

 
I've been meaning to post this for a while but the recipe was at school and 
I usually read my mail from home. Here's a cone 6 majolica recipe that one 
of my students developed in the glaze class last semester. It has very 
low amounts of boron (in the form of gerstley borate) so it better supports 
a wide range of stain colors, even pinks, lavenders and other somewhat 
fugitive colors. It should fit most clay bodies, but you may have to adjust 
it to fit yours with out crazing or shivering. 

Glaze name: Midrange Majolica 96 
Cone: 4 - 5 - 6 
Color: Opaque White 
Testing: Tested 
Surface texture: Shiny or Glossy 
Firing: Ox. or Red. 

Recipe: Percent Batch 
Gerstley borate 4.85 242 
Nepheline Sye. 30.09 1504 
EPK 4.20 210 
Dolomite 2.07 103 
Whiting 8.49 424 
Flint 41.09 2054 
Zircopax 9.21 460 
Totals: 100.00 % 5000 Gm 

Also add: 
Bentonite 3.00 150 
Epsom salts 0.50 25 

Comments: 
From Linda Litteral - SDSU Glaze class 1996. She called it 'A-7 
Chinese.' Tested for new Midrange majolica for class use. Almost boron 
free - good for stain colors that are subject to dissolving in boron 
glazes. Very stable, does not move during firing unless quite thick. 
Will crawl slightly if very thick. Applies well either by dipping or 
brushing. Works well with almost all Duncan EZ-Stroke underglaze 
colors as majolica washes, as do Amaco velvet red versions of the 
zirconium encapsulted red stains. Probably most stains would work well 
also. Color possibities: Use mason stains mixed 50/50 with Pemco frit 
P-25 or Ferro Frit 3124, or use 70 stain/30 gerstley borate in a 
watery mix for colors over glaze or some combination of gerstley 
borate and frit. Using too much gerstley borate may make the stain 
change color or become pastel. Purple stains may need to have more 
flux added up to 3 parts flux to 1 part stain. If you use all frit, 
add liquid starch or CMC to colors for easier brushing and to minimize 
smearing before they're fired. Use these Duncan EZ-stroke transparent 
underglazes as overglaze wash for color: EZ003, EZ004, EZ007, EZ012, 
EZ014, EZ019, EZ020, EZ021, EZ024, EZ025, EZ027, EZ028, EZ030, EZ032, 
EZ161. Almost all the other EZstrokes will work, especially if thinned 
slightly. The darker blues and the Sierra Yellow EZstrokes will 
wrinkle and get rough if applied too thickly. CoverCoat CC 154 should 
work as well. Most other CoverCoat colors will work when thinly 
applied, but may be dry if thick. Try adding a teaspoonful of frit or 
gerstley borate to a jar of CC underglaze for glossier color. Other 
color possibilities include washes of the common colorants (mix chrome 
and rutile 50/50 with gerstley borate or frit). A thin red iron or red 
earthenware slip or possibly a red terra sigillata on the foot or 
other exposed clay areas makes a nice contrast if used on a white clay 
body. Other color possibilities: A nice dark blue green with: 2% 
cobalt carb + 3% chrome oxide + 2% black iron oxide added to the 
glaze. 

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Marcia

 

Thanks for your help on this. Your expertise is far beyond mine.

 

I may have been a little too cryptic in describing what I'm looking for. I need a very stiff ^6 glaze that takes colorants well. As you'd expect high zircopax glazes make all of my colors very pastel, which is not what I want.

 

What happens if I leave out the zircopax...Or put much less of it? Would this give me a more clear glaze... In the recipe you offer or the one below. Which of the two glazes do you think would be better. I do have a good supply of the original  Gerstley borate.

 

I found this in one of Linda's handouts (the one in Mastering cone 6...looks like it could move a bit??)

 

San Diego State U Majolica - C 6
Dolomite 2.3
Whiting 8.7
Feldspar 35.8
 EPK 5.8
Flint 35.7
Frit 3124 10.5
  +Zircopax 1
+Bentonite 2
 +Epsom salts 0.6
 Use 50 stain/50 frit over. Add CMC
gum soln. for better brushing and

harder raw surface.  

 

Thanks Larry

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doc, i use a white glaze that does not move.   sorry, i do not understand the word "stiff" as a descriptor of a glaze so i do not know if you are interested in the recipe or not.  let me know.

 

in re-reading your original post i see that you are asking for a clear glaze.  the recipe i mentioned is a clear base to which i add zircopax to make it white.

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doc, this is from George and Nancy Wettlaufer's great book "getting into pots".   page 127 has lots of great glazes that might work on your clay.

 

extra shiny clear  cone 6

 

soda spar                              40

whiting                                    20

ball clay (i use c&c)              10

zinc oxide                               5

silica (i use 325)                    20            

yes, i know it is 95 not 100

 

my personal addition is bentonite,2%    if you want to make it white, use 20% zircopax.  on my white clay, the white is blinding.  there are some empty bowls in my gallery that show how stroke & coat colors work on top of the white.  the flowers are applied with cut foam rubber teardrop shapes and repeated to form petals.

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  • 2 years later...
On 9/25/2016 at 3:27 PM, Marcia Selsor said:

Linda Arbuckle on tue 2 jul 96

 

Richard Burkett on tue 22 oct 96

 

This one quoted above by Marcia works very well. It will hold a very sharp edged piped shape at: ^6 oxidation.


I made one modification I substituted FF 3134  1 to 1 for the gerstley borate. I also found that if you want even stiffer adding up to 20% alumina hydrate will make it very stiff when it is mat finish at that point

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