Wyndham Posted June 15, 2013 Report Share Posted June 15, 2013 Jim posted earlier in the thread I think that one is okay. Here's what I have for SCM Warm Custer ... 39.6 Whiting ... 14.9 Strontium Carb ... 10.9 EPK ... 12.9 Frit 3124 ... 3.9 Lithium Carb ... 3.9 Titanium Diox ... 11.9 Bentonite ... 2.0 Yellow Iron Ox ... 2.5 Something that was passed on to me that might be worth trying is using calcined epk for about half of clay in the recipe and regular epk for the rest. This will cut down on the peeling off of some glazes when a second layer is dipped or sprayed. I use this idea when my glaze calls for 10% or more of clay and it has always helped. Hope this helps Wyndham Link to comment Share on other sites More sharing options...
OffCenter Posted June 15, 2013 Report Share Posted June 15, 2013 Jim posted earlier in the thread I think that one is okay. Here's what I have for SCM Warm Custer ... 39.6 Whiting ... 14.9 Strontium Carb ... 10.9 EPK ... 12.9 Frit 3124 ... 3.9 Lithium Carb ... 3.9 Titanium Diox ... 11.9 Bentonite ... 2.0 Yellow Iron Ox ... 2.5 Something that was passed on to me that might be worth trying is using calcined epk for about half of clay in the recipe and regular epk for the rest. This will cut down on the peeling off of some glazes when a second layer is dipped or sprayed. I use this idea when my glaze calls for 10% or more of clay and it has always helped. Hope this helps Wyndham Good post, Wyndham. That's very helpful. I suggested that the guy who started the following thread about glazes over SCM peeling check out your post here. http://ceramicartsdaily.org/community/topic/4247-multi-layer-glazes-peeling/page__pid__36899__st__0entry36899. Jim Link to comment Share on other sites More sharing options...
John255 Posted June 15, 2013 Author Report Share Posted June 15, 2013 Clay Lover, The advice Jim is posting about dipping vs. spraying for SCM is right on. I found it necessary to go to much larger pieces, and spraying. See attached. At present I'm almost ready to go for another kiln load with SCM sprayed much thinner than before with companion glazes that contain more RiO, but I have a house full of company. Changing glazes with a single gun can be a pain, but with a written plan the underglazes can all be done first then all the greens/browns/reds etc. combinations are done in sequence one color at a time to minimize changing. Hang in there. John255 Link to comment Share on other sites More sharing options...
docweathers Posted June 15, 2013 Report Share Posted June 15, 2013 From summer of 2011 his schedule for glaze firing if he used bisqued not raw pots: segment 1 - 200F/hr - 220 - hold 30 mins if you have raw cone packs in the firing segment 2 - 400F/hr - 2100 - 0 hold segment 3 - 100F/hr - 2170 - 30 to 60 min hold until ^6 falls, tweaking required segment 4 - 9999F/hr - 1700 - 0 hold segment 5 - 50F/hr - 1600 - 60 min hold segment 6 - 50F/hr - 1500 - Off He says that since kilns are calibrated differently and he doesn't use bisque pots that the above schedule would be some approximation of what he would use. Min Here is a little more recent and slightly different version Steven Hill 2/13/12: Ramp 1: 200ºF/hour to 220ºF Hold 1 - 3 hours, depending on the dampness and or thickness of the work. Ramp 2: 100ºF/hour to 500ºF No hold Ramp 3: 400ºF to 500ºF/hour to 2100ºF No hold Ramp 4: 100ºF/hour to 2160ºF-2190ºF 60 Minutes—this temperature is about cone 5, with an hour soak Cone 6 should fall. Not all kilns are calibrated the same, some adjustment may be necessary. Ramp 5: 9999ºF/hour to 1700ºF No hold Ramp 6: 50ºF/hour to 1600ºF 45 - 60 minutes Ramp 7: 50ºF/hour to 1500ºF No hold, kiln off. Link to comment Share on other sites More sharing options...
John255 Posted June 16, 2013 Author Report Share Posted June 16, 2013 From summer of 2011 his schedule for glaze firing if he used bisqued not raw pots: segment 1 - 200F/hr - 220 - hold 30 mins if you have raw cone packs in the firing segment 2 - 400F/hr - 2100 - 0 hold segment 3 - 100F/hr - 2170 - 30 to 60 min hold until ^6 falls, tweaking required segment 4 - 9999F/hr - 1700 - 0 hold segment 5 - 50F/hr - 1600 - 60 min hold segment 6 - 50F/hr - 1500 - Off He says that since kilns are calibrated differently and he doesn't use bisque pots that the above schedule would be some approximation of what he would use. Min Here is a little more recent and slightly different version Steven Hill 2/13/12: Ramp 1: 200ºF/hour to 220ºF Hold 1 - 3 hours, depending on the dampness and or thickness of the work. Ramp 2: 100ºF/hour to 500ºF No hold Ramp 3: 400ºF to 500ºF/hour to 2100ºF No hold Ramp 4: 100ºF/hour to 2160ºF-2190ºF 60 Minutes—this temperature is about cone 5, with an hour soak Cone 6 should fall. Not all kilns are calibrated the same, some adjustment may be necessary. Ramp 5: 9999ºF/hour to 1700ºF No hold Ramp 6: 50ºF/hour to 1600ºF 45 - 60 minutes Ramp 7: 50ºF/hour to 1500ºF No hold, kiln off. Doc, Thanks for posting the latest SH schedule. Looks like he's lengthening the 2nd ramp probably for issues with his single-fire ware in that temperature range? With bisqued ware I had to slow down the 3rd ramp to off-set a slight amount of bloating on the surface of the self-supporting cones. 375F/hour to 2100F cleared up the problem in my small test kiln. Regards, John255 Link to comment Share on other sites More sharing options...
Min Posted June 16, 2013 Report Share Posted June 16, 2013 Jim, Thank you for the comments on the photography. I've been at it for a very long time. Yes, it seems we are dealing with a subject that has been very easy to overlook; the purity of RiO. I have you and Min to thank for this revelation. I had a similar experience with RiO going birds-egg speckled. See attached Interesting to note that the normally white tin was colored dark ivory overall in addition to the dark crystal clusters. The iron and tin were used in a high-calcium mat formula. I'm not sure if the result is from the quality of iron or the combination of iron and calcium. John255 Ball milling will take care of the speckles. Min Link to comment Share on other sites More sharing options...
clay lover Posted June 17, 2013 Report Share Posted June 17, 2013 Thanks for the dipping suggestions, OC. I will get into trying these glazes again this summer. I mixed several of them after taking a workshop with SH about a year ago. I will make beefier test tiles and have another go. SH says SCM should be 60% of the total glaze thickness, so I was operating off that. My spraying tests worked well, just would like a more efficient way to try lots of combos. It's good to know others that are working with these glazes, hope we can continue to support each other's efforts. There is a web group about this, but it seems dead and is very difficult to navigate. John, thanks for the pictures, nice results. Link to comment Share on other sites More sharing options...
John255 Posted June 17, 2013 Author Report Share Posted June 17, 2013 Ball milling will take care of the speckles. Min Min, That would possibly be an excellent fix if you had a huge batch of RiO that need to be used up. However I think I'd be looking for another source of Rio with better quality control. The orifice on my touch-up gun is .6mm so I have to sieve all of my glazes through 100 mesh screen. The only thing I pick up and have to compensate for is lithium, even the "fine" variety. Another aspect is I only get the speckling from one bag of RiO with one glaze formula. If you believe in kiln gods that speckling my be perfect for something, and when its used up, its gone forever. Regards, John255 Link to comment Share on other sites More sharing options...
John255 Posted June 17, 2013 Author Report Share Posted June 17, 2013 Thanks for the dipping suggestions, OC. I will get into trying these glazes again this summer. I mixed several of them after taking a workshop with SH about a year ago. I will make beefier test tiles and have another go. SH says SCM should be 60% of the total glaze thickness, so I was operating off that. My spraying tests worked well, just would like a more efficient way to try lots of combos. It's good to know others that are working with these glazes, hope we can continue to support each other's efforts. There is a web group about this, but it seems dead and is very difficult to navigate. John, thanks for the pictures, nice results. Clay Lover, OK, I know the forum you are speaking of and I agree it is dead. SH makes that statement on the DVD about 60% SCM underglaze. When I do that it slides off the pot with a very dry surface. I'll be firing another approach this week. Yes, it is great to have this discussion. I wish now I had chosen another name for this thread. There are so many variables in the work we do it is amazing we can share meaningful detail at all. Regards, John255 Link to comment Share on other sites More sharing options...
OffCenter Posted June 17, 2013 Report Share Posted June 17, 2013 Thanks for the dipping suggestions, OC. I will get into trying these glazes again this summer. I mixed several of them after taking a workshop with SH about a year ago. I will make beefier test tiles and have another go. SH says SCM should be 60% of the total glaze thickness, so I was operating off that. My spraying tests worked well, just would like a more efficient way to try lots of combos. It's good to know others that are working with these glazes, hope we can continue to support each other's efforts. There is a web group about this, but it seems dead and is very difficult to navigate. John, thanks for the pictures, nice results. Obviously, Steven Hill knows more about his glazes and techniques than I do, but when SCM is thicker than the glaze over it (in my case often Juicy Fruit) I tend to get a muddy yellowish color. When I reverse it and the SCM is thinner than the glaze or glazes over it, I get better reds and golds. I guess it depends on the glazes, and only tests will determine what works. Jim Link to comment Share on other sites More sharing options...
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