Tuesday, December 27, 2011

Cone 6 soda test tile results

The cone 6 soda test tile firing looks very promising. I will need to re-fire tiles because we only reached cone 6 just starting to soften. Cone 7 looked like it was at 3 o'clock; but it turned out that it was just in the process of toppling over. Guess I didn't seat it well enough in it's little house. With only one cone pack visible I asked John to just shut it down, rather than risk over-firing, which was a good call, since I was more interested in getting a true picture of the flashing slip at cone 6, not cone 7.

These tiles look more promising than the tiles from the Energy Exchange's wood/soda firing. They're brighter, and with the new soda mix, it looks like they will flux more at a full cone 6. They also showed more flashing potential in this firing with this new soda mix. As I suspected, the wood in the Energy Exchange firing made the tiles drier. The yellow slip was a great example to show the difference. It was buttery on all 3 tiles but dry at higher temperature in the Energy Exchange firing.

The draw rings were very good and some of the glazes are good at cone 5. One oribe is a beautiful, rich, dark green and the turquoise oribe also looks promising. A matt white was under fired at cone 5 as was Reeves green, and another oribe.

I'll make new tiles for the shinos and a few others and start body reduction a bit earlier next time and do it a bit heavier,reduction next time. Two of the of the shinos were mature at cone 5 and look good as potential liners. They just need more and earlier reduction to shine. The one temmoku in the firing was brown; but re-firing might help. I think I'll also do another version. I have to check which Iron I used, but I thought I used a very high purity iron and was expecting black, not dark brown. John has one C 6 temmoku that I'll try as well. I forgot to put my celadon liner in this firing, so that will go in with the re-fires along with another one from John.

My new gloss base looked good, but some of the tiles got hit with too much soda - difficult to avoid in a small kiln with only test tiles. My yellow slip (Linda's yellow with my revisions) turned out great on all bodies tested. Another really nice surprise was 2 versions of a known glaze called Juicy fruit - better at cone 5 in soda and light reduction than in my full cone 6 oxidation firing using Steven Hills firing schedule.

I'll be spending another day or two making some charts, cataloging these with follow up notes, then it will take another couple of weeks after the holidays to make, bisque and dip new tiles and then wait for two days of consecutive good weather to fire them; but I'm very happy with all the information and more potential good results with some tweaking and re-firing.

I also want to batch some new revisions of a couple of flashing slips using Ronans excellent suggestion of replacing Grolleg with EPK and Newman red with Redart.

Time now, to get a cup of herbal tea and start cataloging the other two shelves of tests.

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