Babs Posted April 17, 2015 Report Share Posted April 17, 2015 I've been reading an old Ceramics Monthly mag, highly recommended so informative, and onglaze recipes by John Fassbinder had me wondering . The colourants are written up as %s and I can't see what they are percentages of......Be kind to old ladies. Eg Blue/Brown: 2% Manganese Dioxide; 1% Cobalt Oxide; 1/2%Rutile and 1/2% talc. This was fired to a Cone 10 reduction. Another question. Can Talc be used as an onglaze ingredient at lower temps? he revives them by adding water. So what are these chemicals percentages of? Or are they written as this incase someone wants to use them as colourants in glazes? His onglazes melt into the glazes beautifully Babs Link to comment Share on other sites More sharing options...
bciskepottery Posted April 17, 2015 Report Share Posted April 17, 2015 Sounds like there should be a base glaze recipe in the article, then they listed the colorants for various color options. They could also be colorant percentages for a wash used for decoration. Link to comment Share on other sites More sharing options...
TJR Posted April 17, 2015 Report Share Posted April 17, 2015 It's a percentage of the total glaze that you are mixing. If you have a glaze test of 100 grams-2% manganese would be 2 grams. That is if you were adding it to a glaze. I would try it at 1% assuming it was a glaze test. Mix it up in a cup based on a total of 100 grams, then brush it on. The talc is there as a flux to cause it to melt into the glaze surface. TJR. Link to comment Share on other sites More sharing options...
Babs Posted April 17, 2015 Author Report Share Posted April 17, 2015 bciske, no base glaze... just the onglaze recipes. It stated that he just kept his onglazes in old coffee mugs and added water as he needed...I thought initiallly that it would be in 100ml water, but wouldn't matter and I gues this is the case. TJR I am taking from your comment that I'd mix a ratio of 1:2:0.5:0.5 in order of listings which is what I usually do for onglazing So the talc is ok as a flux at C6? I usually use neph syn or a frit. Link to comment Share on other sites More sharing options...
Magnolia Mud Researdh Posted April 17, 2015 Report Share Posted April 17, 2015 Question: Which "old" CM issue has this article? Without more details about the article, my take is that %s means percent solids in the water-solids mixture. 100 grams water + x %s grams of the specific ingredients. In effect the onglaze decoration is an oxide wash over the glaze already applied to the pot (cups in this case). Unlike a single component oxide wash, his onglaze concoction needs several oxides (or ingredients) in a particular ratio to produce his desired effect. The %s nomenclature assures that the wash, when thoroughly suspended, provides the ingredients in the needed ratios. Link to comment Share on other sites More sharing options...
bciskepottery Posted April 17, 2015 Report Share Posted April 17, 2015 bciske, no base glaze... just the onglaze recipes. It stated that he just kept his onglazes in old coffee mugs and added water as he needed...I thought initiallly that it would be in 100ml water, but wouldn't matter and I gues this is the case. TJR I am taking from your comment that I'd mix a ratio of 1:2:0.5:0.5 in order of listings which is what I usually do for onglazing So the talc is ok as a flux at C6? I usually use neph syn or a frit. Looking at his work, I'm inclined to think it for an oxide wash or for decorating . . . Link to comment Share on other sites More sharing options...
Babs Posted April 18, 2015 Author Report Share Posted April 18, 2015 The Ceramics Monthly is November 1979. Thanks everyone. I think the amount of water will be variable and JF , as he allows it to sit in old coffee mugs, just knows what consistency he needs. He uses these mixes for onglaze dec. which melt into the glaze, I'll post a pic later. IS it ok to photo out of a mag to post here? This guy throws/threw one piece goblets from the hump. solid stem and foot, does anyone do this now? Link to comment Share on other sites More sharing options...
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