Mudfish Posted February 15 Report Share Posted February 15 out of dolomite at the moment and looking for a good matte/satin matte white-ish base glaze. Does anyone have any insight into this cone 10 glaze "Horsely's Satin Matte White? * Custer 49.19 * Whiting 29.95 *Om4 21.62 * EPK 3.24, Zirco 12%, Titanium 4.8%, zinc 4.8% How does this formulation react over colored slips, especially? I sometimes have trouble with shivering. Shivering happening on rims and over slip/colored slip applications. I use stoneware. Standard #153, cone 10, and sometimes I use Standard stoneware white #181. Thanks, everyone Quote Link to comment Share on other sites More sharing options...
Min Posted February 16 Report Share Posted February 16 If nobody here has used that glaze maybe it's worthwhile contacting him and asking about it. Just looking at the materials it's going to be an opacified calcium alumina semi matte. Calcium tends to bleach out iron a bit. I'm sure you already know this but some people think zinc in a reduction firing helps get the melt started but then given it's volitility is gone by the end of the firing. Your dolomite glaze shivered? Pat Horsley's website and contact form here. Mudfish 1 Quote Link to comment Share on other sites More sharing options...
Mudfish Posted February 16 Author Report Share Posted February 16 No, the glaze that shivered is not a matte. I subbed the 22 parts dolomite in the formula with 10 parts bone ash, and 12 parts talc. The rest of the formula called for 48.3 parts custer, 25 parts EPK, (which I used about half calcined Epk for that), and 3.8 parts whiting. I'm just guessing that it was the materials I subbed for the dolomite that made it shiver, and it was also much more glossy than I expected Quote Link to comment Share on other sites More sharing options...
Min Posted February 16 Report Share Posted February 16 The talc is going to have a lower COE than the dolomite, that might be it? Do you have a big bucket of it? Mudfish 1 Quote Link to comment Share on other sites More sharing options...
Mudfish Posted February 16 Author Report Share Posted February 16 Yes, it must have been the talc, and yes, I got a 5 gallon bucket full. Is there anything I could add that might help? Quote Link to comment Share on other sites More sharing options...
Min Posted February 16 Report Share Posted February 16 This is going to be a long shot. Recipe? Quote Link to comment Share on other sites More sharing options...
Mudfish Posted February 16 Author Report Share Posted February 16 Custer 48.3 Epk 25 (used calcined for a third of this) 3.8 parts whiting Original formula called for 22 parts dolomite, which I subbed the talc/bone ash, because I am out of dolomite. Also, I added 3 percent manganese carb, and 3 percent titanium. It shivered on the rim of a few mugs, and I'm assuming it was from a light application of white slip that I applied at the greenware stage Quote Link to comment Share on other sites More sharing options...
Min Posted February 16 Report Share Posted February 16 3 hours ago, Mudfish said: It shivered on the rim of a few mugs, and I'm assuming it was from a light application of white slip that I applied at the greenware stage Is it shivering on rims that don't have the white slip? I'm wondering if the slip is shelling off the pot on the rims and taking the glaze with it. Have you used this slip with the original dolomite version of the glaze successfully? Any chance you have a piece you could put in the glaze fire with the slip but without any glaze on it? I had a look at the formulas for the dolomite version compared to the bone ash + talc version, while there are differences they are not a world apart. There is a fair bit more silica in the bone ash + talc could explain the glossiness. Quote Link to comment Share on other sites More sharing options...
Mudfish Posted February 17 Author Report Share Posted February 17 Thanks, Min. This glaze only shivered over the rims that had the slip application. So, my next question, are some slips more compatible with various glazes than others ? Also, is it better to formulate slip/colored slips using my clay body slurry? This seems like a solution to me Quote Link to comment Share on other sites More sharing options...
Min Posted February 17 Report Share Posted February 17 2 hours ago, Mudfish said: So, my next question, are some slips more compatible with various glazes than others ? Also, is it better to formulate slip/colored slips using my clay body slurry? This seems like a solution to me Yes to both questions. I would suggest just putting that 5 gallon bucket of glaze to one side for now without trying to adjust it. Make up some slip with your claybody and try that with your colouring oxides or stains. Your altered glaze might be just fine the way it is. Mudfish and Callie Beller Diesel 2 Quote Link to comment Share on other sites More sharing options...
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