glazenerd Posted March 4, 2016 Report Share Posted March 4, 2016 For three years I have been trying to perfect a no-run Cone 6 crystalline glaze recipe. There is less than a half of teaspoon of glaze run off in the catcher. There is none on the sides or the rear. I think this side only has it because I applied a little too thick towards the bottom. I can make it completely run free, but that hinders crystal development too much. For those unfamiliar with this glaze: losing up to 1/3rd of the glaze in the catcher is normal. My next step is to send it out to 5-6 other potters that have never worked with it before to see how it field test for them. Needs a touch more SiO2 to heal the crazing issue. Nerd Link to comment Share on other sites More sharing options...
Mark C. Posted March 4, 2016 Report Share Posted March 4, 2016 And I thought soft brick pads where used to soak up the runs? Nerd do those glaze catchers get reused much before breaking or getting tossed? Link to comment Share on other sites More sharing options...
glazenerd Posted March 4, 2016 Author Report Share Posted March 4, 2016 Mark: Normally I can get 6-8 firings from one catcher, sometimes more. The trick is to use a 50/50 EPK/Alumina paste to set the piece onto the catcher. The COE of this mix is way off from porcelain, so a simple tap on the catcher usually makes it release. I put a 6" carbide wheel on my bench grinder: in less than 30 seconds I have a nice smooth bottom. Actually if you took a scrap tile and put it under the piece with a thick coating of dry silica: tap it and throw it all out works too. There is no reason why this glaze cannot be more user friendly. Nerd Link to comment Share on other sites More sharing options...
MatthewV Posted March 4, 2016 Report Share Posted March 4, 2016 I would love to try it. But a fair warning: I am not good at keeping recipes secret. I haven't done crystal glazes yet but it is on my to try list. Crazing in a crystal glaze doesn't seem all bad for many forms. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 4, 2016 Report Share Posted March 4, 2016 When I made crystalline glazes, (my thesis in 1973) I used a 1/2" slice of soft brick cut to fit the pot which was bisqued to ^9 and kiln washed with high alumina mix. The whole premise of growing the crystals is the excessive fluidity for "freezing" the surface by a fast temp. drop and hold to grow the crystals. Your test piece looks like successful crystals forming and the excessive flow isn't so bad. Good job with the experiments. Marcia Link to comment Share on other sites More sharing options...
flowerdry Posted March 4, 2016 Report Share Posted March 4, 2016 I like the look of the crazing on that piece. Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted March 4, 2016 Report Share Posted March 4, 2016 Very impressive work, I am sure it would be even more awesome if I had ever fired a crystal glaze and had seen the aftermath personally. Link to comment Share on other sites More sharing options...
Joseph Fireborn Posted March 4, 2016 Report Share Posted March 4, 2016 Very impressive work, I am sure it would be even more awesome if I had ever fired a crystal glaze and had seen the aftermath personally. When I first started. I didn't know much. I bought some commercial crystal glazes and read the firing schedule and programmed it in and fired it. I promptly threw away the kiln shelve afterwords with the pot stuck to it and decided to throw away the crystal glaze as well. Talk about a mess. I didn't even want to attempt to grind that. Link to comment Share on other sites More sharing options...
glazenerd Posted March 4, 2016 Author Report Share Posted March 4, 2016 Thanks all for the comments and compliments. Marcia: There is a trade off for controlling the glaze run off: the crystal development is different than a cone 9-10. Matthew: I will be sending out premixed samples, not the recipe. Cone 10 crystal: Marcia: in 1973 you were probably using Pemco 283 Frit. The zinc was probably 75% pure and roughly the same for silica. The technology changes in kilns and in products has changed our ability to deal with this glaze. Zinc is 98.9%, and the same for silica. These purity levels require less fluidity and less heat to accomplish a full melt. I will be posting another type of crystal glaze here shortly. To my knowledge it has not been introduced before: again I stress to my knowledge. (the world is a big place.) Nerd (Tom Anderson)... but don't tell anyone.. I am lurking. Link to comment Share on other sites More sharing options...
MatthewV Posted March 4, 2016 Report Share Posted March 4, 2016 Matthew: I will be sending out premixed samples, not the recipe. I cannot blame you! I would still be willing to make a sample piece with the ∆6 clay I use and provide feedback. Link to comment Share on other sites More sharing options...
glazenerd Posted March 4, 2016 Author Report Share Posted March 4, 2016 Matthew: send me an address via PM....Will send you 150-200 grams; should be enough to do two smalls pieces. Will send you the rutile/Nic ox shown above, and a medium green. lite tan field. Instructions for application and mixing will be enclosed. Will be another two weeks, sold my office/warehouse and am under the gun to get it cleared out and have a massive tool auction. After 42 years of swinging a hammer, doing something easier- like glaze. Nerd Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 5, 2016 Report Share Posted March 5, 2016 Glazenerd, Here is a youtube about kiln karma and crystalline glaze. Thought you might enjoy this. https://www.facebook.com/groups/503156473036283/1143464432338814/?notif_t=group_activity Marcia Link to comment Share on other sites More sharing options...
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