Fredrin Posted August 10, 2016 Report Share Posted August 10, 2016 Hello all, This is my first post here, though I have been stalking these forums for a while! To briefly introduce myself, I have recently started out as a studio potter in Walthamstow, East London (home to William Morris and birthplace of the Arts and Crafts movement way back when). I studied ceramics from 13-18, developing a love for the smoke and drama of Raku and rediscovered the joy of clay just over a year ago - been an addict ever since I'm lucky enough to work with a talented illustrator who puts underglaze designs on some of my porcelain and white stoneware pieces, but I have rather been letting the side down lately by covering her lovely drawings in a rather funky looking transparent (a pre-mix from the local supplier). The effect I'm going for is a perfectly transparent with a very high gloss, but what I'm getting is a milky glaze with a bizarre crinkly textured surface that is neither matt nor shiny! Here's what it looks like: I've fired to cone 6,7 and 8 with varying thicknesses and keep getting similar results. Please can you lovely people recommend a recipe that produces a high sheen and will really bring out an underglaze design on a porcelain/stoneware body. Many thanks! Link to comment Share on other sites More sharing options...
dhPotter Posted August 10, 2016 Report Share Posted August 10, 2016 Try This... https://digitalfire.com/4sight/recipes/cone_6_ultraclear_glaze_for_porcelains_106.html Link to comment Share on other sites More sharing options...
Marcia Selsor Posted August 10, 2016 Report Share Posted August 10, 2016 Wayne Bates Clear cone 6 from PMI F-4 Feldspar 35 Gerstley Borate 23 Whiting 8 Strontium 8 EPK 8 Flint 18 100 OR USE THIS WITHOUT THE COLORANTS Selsor Faux Celedon ^6 Oxidation Whiting 18.5 Neph Syen 25.8 EPK 18.8 Silica 31.1 Gerstley B 4.6 98.8 Copper carb 0.3 Mason #6600 Black 0.02 Link http://community.ceramicartsdaily.org/gallery/image/3541-cone-6-faux-celedon/ Link to comment Share on other sites More sharing options...
Fredrin Posted August 10, 2016 Author Report Share Posted August 10, 2016 Thanks I was about to ask if Matt Fiske's faux celadon (minus colourant) would be suitable. Is it important to give these glazes a long soak? Link to comment Share on other sites More sharing options...
Marcia Selsor Posted August 10, 2016 Report Share Posted August 10, 2016 not really. 15-20 minutes is sufficient. Marcia Link to comment Share on other sites More sharing options...
Min Posted August 10, 2016 Report Share Posted August 10, 2016 My favourite ^6 clear for over underglazes on porcelain is this one https://digitalfire.com/4sight/recipes/low_expansion_glossy_clear_cone_6_45.html. The 3249 frit is ridiculously expensive but I've done a version of this glaze subbing other stuff for it if you want it. Never boron cloudy, super forgiving glaze. (spectrum underglazes) (porcelain kids bowls) Link to comment Share on other sites More sharing options...
Joseph Fireborn Posted August 11, 2016 Report Share Posted August 11, 2016 Thanks I was about to ask if Matt Fiske's faux celadon (minus colourant) would be suitable. Is it important to give these glazes a long soak? I dont think this will work well, Fiske's faux celadon has a beautiful bubble matrix I did a lot of testing with it. He personally likes the bubble matrix in it, as do I. If you put it on really thin though there isn't much of a bubble matrix happening, I think your better off with a real clear recipe. I just worked with that glaze for the better part of 3 months testing and changing it slowly. Link to comment Share on other sites More sharing options...
oldlady Posted August 11, 2016 Report Share Posted August 11, 2016 recipe GLOSSY CLEAR, NO ZINC cone 6 Kona F4 (or minspar) 35 Gerst;ey Borate 23 silica 18 barium carbonate 8 whiting 8 EPK 8 this works very well on my clay. who knows what it will do on yours. i use it because it does not affect underglaze or slip colors under it. very shiny clear. i don't like barium so if anyone knows a perfect substitute for it, please tell me. pic is of a soapdish i made with leftover strips of a cone 6 porcelain and my friend denise did the frog, her trademark. Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted August 11, 2016 Report Share Posted August 11, 2016 Did going hotter improve it at all? Looks under fired. If you want to do a little bit of testing buy a feldspar, china clay, quartz(silica), frit and whiting. If you look at all these recipes that is what they are. Well they use gersbor~ to source boron but I think a frit will work better for clear. Link to comment Share on other sites More sharing options...
Fredrin Posted August 13, 2016 Author Report Share Posted August 13, 2016 Thanks to all for the great advice. I've had a word with the supplier and as High Bridge Potter suggests above, I will go to a higher temp (cone 8) and give it a 30 minute soak. Under-firing seems to be the main problem. I'll try out some of the recipes above but as a shortcut until I've got one fully tweaked, I've bought some Amaco clear celadon Link to comment Share on other sites More sharing options...
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