I had the strangest thing happen in my last firing--before the celebrations began! I mentioned making some dinner plates as a test to see if I could make a set that was at least similar. Well, they looked similar when I put them into the kiln--but not when they came out! There were 3 that were very much alike and one that was more bowl-like. I glazed all 4 with the same glaze and in the same manner. But, of course, they were in different spots in the kiln: one on the very bottom shelf, two on the shelf above that and one on the next to the top shelf. Each shelf produced a different product. The photos don't show the differences as well as the eye--but you can see what I got, this is the piece that was the lowest in the kiln.
I don't have a good photo of the two what were in the middle of the kiln but they were the darkest--and were almost identical.
This plate was the highest in the kiln (though not on the top shelf).
The cone packs show the variation in the heat-work. The top shelf is on the left and the bottom pack is on the right. I've been using this glaze for a long time. I never realized how heat-work sensitive it is. I had seen variations in the fired pieces but attributed it to glaze application (or thickness) but that is not the explanation this time!
I am not so confident about making 'sets' now!
10 comments:
Is the glaze Jade Green? I have had this happen to me with Jade, it is such a fussy glaze with heat.
Pretty plates though
No, it is not Jade Green--though the inside of the piece on the lowest (coolest) part of the kiln does look similar to Jade Green. It is a glaze I got from June Perry's ^6 collection on the web that I altered, accidently, but liked the result.
Thanks, I like the plates but now see I won't have as much control over them as I thought. That is probably a good thing!
I like the color on both of these. I think sets are over rated anyhow. Similar is good. Identical is boring. (for me anyhow) I do want to say you'd get an A++ from me for having cones in the kiln!!! I like the texture on the rim too.
Ron, yes, I get the boring part of sets but I was very surprised at the extreme differences in these pieces. Not to say I'd be opposed to using them together but still amazed at the differences. Are you not surprised? Perhaps the difference does not show up so much in the photos...I need to take Joy's photo workshop!
Among my small group of ^6 potter friends I am always pushing the use of cone packs--but mostly just get blown off. I'd be lost without them.
I like both of the color variations you have shown very much, and the texture on the rim. If it was me and I wanted to make sets I would fire several times, the middle shelf ones would be one set and the other ones another set. I'd go with the flow of the kiln and glaze. Wonder if you fire another set if the different shelves will end up being similar to the ones you just fired.
Linda, I will try that. I had not thought of trying to make sets of 'bottom shelf' and of 'middle shelf' and so on. But, that is a great idea! I keep records of the firing schedules as well as use the cone packs--some might say I am bit obsessive! But it is a great aid. It will be a test of my kiln and of my record keeping!
I would say that your glaze color is reacting to the temp difference in that one kiln section. I would work on getting temp consistency within your kiln. I always use witness cones because my kiln temp varies drastically when I load the shelves different or even when I have a light load vs a full load. So many variables to keep track of.
Yes, Cindy, that is my conculsion, too. Originally, my kiln fired incredibly even--top to bottom. But it is not now. I have been trying to control it with adjusting the load and the depth of the shelves--but have not gotten there yet. Linda's suggestion sounded more achievable! But that may not be as easy as it seems!
Hi Gay,
I agree that the color difference is do to temperature differences. I have a glaze I love, seafoam green, that I use in the ^10 soda kiln. And boy does it vary from locations in the kiln. Here reduction has more to do with it besides temp. The more oxygen in the enviro. the more green. It if gets a lot of reduction, a good soak and a slow cool it comes out red! Or if I fire it twice I get red in interesting patterns. Be mindful though of green glaze on food ware. Usually no more than 6% in the recipe. You can test it by letting a plate or bowl sit with vinegar overnight or a lemon and see if there is a color change from the acid. Good luck. The pieces are beautiful, well done! rachelle
Thanks, Rachelle. I have tested the glaze with lemon and it does hold up OK! I use it a lot. Guess I'm off on a new level of work with it now. Nothing boring about working with clay!
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