PottaFella Posted February 5, 2015 Report Share Posted February 5, 2015 Trying to achieve a very pale, subtle cream glaze effect – a sort of cool/warm off-white is what I'm after. I would also like to get a bit of speckle in it if I can (though that may have to come from the clay). The base glaze is a satin-matt, the recipe is below (on its own it gives a not unpleasant stoney grey/white). I am about to do some test tiles and would appreciate any ideas of what I can throw into the mix and possible starting percentages. I was going to try the following in various small percentages (say from half percent up to 2 or three percent) and mixtures: Rutile (I tried 5% of this in an earlier test and it was far too yellow/strong) Titanium Dioxide Manganese Dioxide Tin Oxide Red Iron Oxide – too powerful? Am I missing anything here? Any to avoid or definitely try? This is my base glaze: Soda Feldspar 70 China clay 13 Dolomite 5 Whiting 4 Zinc Oxide 5 Quartz 3 Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted February 5, 2015 Report Share Posted February 5, 2015 You could try a different feldspar, I find cornish stone gives a much creamier glass. Maybe swap out 50% of the soda for that. Increasing the china clay could also get closer to the off white but it will become more refractory.. Maybe a darker ball clay could work too. Not sure about the colourants, a very low percentage could give you what you want. Here are some of my melt tests, if you look at the feldspars across the top it goes soda, potash, cornish stone. Cornish stone to me looks the most off white. Do you have any photos of your tests? Link to comment Share on other sites More sharing options...
bciskepottery Posted February 5, 2015 Report Share Posted February 5, 2015 So, this is the third time I've typed and uploaded this post . . . and the last time I'll try. Here is a glaze called Antique White -- Cone 6, oxidation. The bowl is a dark brown stoneware (Standard 266). Antique White Nepheline Syenite, 41.7% Silica, 16.7% Gerstley Borate, 25% EPK Kaolin, 8.3% Whiting, 8.3% Total, 100% Bentonite, 2.2% Tin Oxide, 8.3% Red Iron Oxide, 0.9% The dash of RIO takes the harshness off the white of the Tin Oxide. Those two may work with your base glaze. Link to comment Share on other sites More sharing options...
neilestrick Posted February 5, 2015 Report Share Posted February 5, 2015 The alumina in your glaze is out of limits, assuming that's a cone 6 glaze. It's probably not really giving a good melt, which is why it's somewhat matte. I would bring down the alumina to get a better melt, and increase the magnesium to bring back the matteness. Color wise, rutile should work for a cream color, but start at 1%. Small percents of iron oxide may work, too. Link to comment Share on other sites More sharing options...
dhPotter Posted February 5, 2015 Report Share Posted February 5, 2015 This glaze is called Butterscotch. It came from the DigitalFire Website. This glaze uses Gerstley Borate. Cone 6 oxidation. CaO......................... 12.08 Li2O........................ 0.48 MgO......................... 1.94 K2O......................... 0.30 Na2O........................ 2.39 TiO2........................ 4.37 Al2O3....................... 7.87 B2O3........................ 15.89 SiO2........................ 50.04 Fe2O3....................... 4.63 ========= 100.00 CaO 0.67* Li2O 0.05* MgO 0.15* K2O 0.01* Na2O 0.12* TiO2 0.17 Al2O3 0.24 B2O3 0.71 SiO2 2.59 Fe2O3 0.09 I reworked the formula to use Boraq instead of GB. Boraq....................... 31.50 Lithium Carbonate........... 1.10 Magnesium Carbonate......... 2.20 EP Kaolin................... 10.20 Silica...................... 25.70 Ferro Frit 3195............. 16.30 Vansil W-30 Wollastonite.... 4.90 Iron Oxide Red.............. 4.20 Ceramic Rutile.............. 4.00 ========= 100.10 CaO 0.67* Li2O 0.05* MgO 0.15* K2O 0.01* Na2O 0.12* P2O5 0.00* TiO2 0.17 Al2O3 0.23 B2O3 0.65 SiO2 2.57 Cr2O3 0.00 Fe2O3 0.09 MnO 0.00* V2O5 0.00 ZrO 0.00 The Boraq Butterscotch is the liner and top half of the mugs. Link to comment Share on other sites More sharing options...
TJR Posted February 5, 2015 Report Share Posted February 5, 2015 I used 2% rutile in a Mamo Matt and got a nice creamy white. Mang. Dioxide is too dark. Tin is an opacifier but very expensive. You would be better using 10% zircopax gto make a white. You could also increase the dolomite in your glaze. You are only at 5%. Try 10%, then 15%. Red Iron Oxide I wouldn't use either. TJR. Link to comment Share on other sites More sharing options...
Mark C. Posted February 5, 2015 Report Share Posted February 5, 2015 What cone are you firing this to?? Mark Link to comment Share on other sites More sharing options...
Benzine Posted February 6, 2015 Report Share Posted February 6, 2015 Bruce, that glaze is excellent. Is it stable or "food safe"? Link to comment Share on other sites More sharing options...
bciskepottery Posted February 6, 2015 Report Share Posted February 6, 2015 Is it stable or "food safe"? Have been using it for going on 6 years with no issues. My cat has been drinking from that particular bowl everyday for past year or so. I've seen no degrading of the glaze from having tap water in it constantly. It was a studio glaze from the community studio I took lessons and taught. Link to comment Share on other sites More sharing options...
PottaFella Posted February 6, 2015 Author Report Share Posted February 6, 2015 What cone are you firing this to?? Mark It is supposed to be cone 6 but with the longer cooling cycle I have instigated, it is actually cone 7+ (at least, cone 7 is fully over!). I'm considering reducing the top temperature but keep the longer cooling. Link to comment Share on other sites More sharing options...
Joseph Fireborn Posted February 7, 2015 Report Share Posted February 7, 2015 antique_white.JPG So, this is the third time I've typed and uploaded this post . . . and the last time I'll try. Here is a glaze called Antique White -- Cone 6, oxidation. The bowl is a dark brown stoneware (Standard 266). Antique White Nepheline Syenite, 41.7% Silica, 16.7% Gerstley Borate, 25% EPK Kaolin, 8.3% Whiting, 8.3% Total, 100% Bentonite, 2.2% Tin Oxide, 8.3% Red Iron Oxide, 0.9% The dash of RIO takes the harshness off the white of the Tin Oxide. Those two may work with your base glaze. Thanks for this glaze recipe and picture. I am obsessed with whites and I have all the ingredients for this one. Plan on mixing it for my next test batch! Link to comment Share on other sites More sharing options...
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