Sorry, it's been a while since my last post. I've been having a whole series of family commitments - which are far from resolved :(( - and they've been keeping me well and truly out of the studio.
Last week, though, I made the time to mix some more glazes - a painstaking task that takes hours! I wanted to test a new cream stoneware recipe along with a blue/green one and a third described as 'tin red'.
I find glazing seriously stressful. There's so much to go wrong. First, you need a decent mix, applying it to the bisqued pots can also prove quite tricky. Before Christmas I mixed up a new recipe that developed huge blisters during firing which popped in the kiln leaving behind raser-sharp edges. Another glaze produced small lumps that sprouted like acne ruining some jugs I'd made.
Then there are those fun nightmares the night I do the glaze firing with visions of the stuff running like water off the pots I made destroying the inside of that rather pricey kiln of mine.
But before I totally give way to self-pity .... more often than not it's good news when the new pots emerge from the sweatbox. Take a look at this week's results ...
First the cream glaze, an ingredient in the mix (rutile) is responsible for those flecks which I rather like. A particularly thick layer around the rim results in fewer flecks. If someone knows why, I'd love to find out!
The tin red applied externally to the bottom part of the goblets and the outside of the bowls shown below didn't turn out as expected AT ALL. I do like the result. Obviously, my hunt for a red glaze continues.
The weirdest results I got when combining cream (inside and around the rim) with blue green on the bottom parts of both goblets and bowls with tin red !!! on the upper outside sections. I also added cobalt oxide to part of the bowls' rims. I haven't got the foggiest why the tin red glaze turned to light blue over the blue/green whereas it produced a rusty kind of almost red and even cerise when applied over cream in the pictures above.
All in all, I am pleased though. All glazes did behave themselves during firing. No blisters, no craters, no creeping away from the surface. Another nightmare averted.
Time to fill a bowl with crumble and cream, put the goblet to the intended use (I choose a cream-coloured one as it looks rather nice against that blood red Sicilian wine), kick off my shoes and do what I know I do well ... celebrate :))))
Looks like you are unraveling this mystery! Your pots look great. Interesting about the rutile! I worked on some rutile a couple of months ago, but in a completely different context. I was looking at the crystal structure of rutile nanowires. Rutile is one of the crystal forms of titanium dioxide, which is actually white. However, by introducing other atoms into the crystal you can produce different colours. Fascinating ;)
ReplyDeleteThat's weird. So it would seem then that the titanium dioxide crystal is affected by other atoms maybe from the other glaze ingredients or even the clay itself which then produces those speckles? The mind boggles yet again ;))).
DeleteIncidentally, there's also tin oxide in the glaze which is supposed to produce white. The cream colour presumably would become ever lighter, the more tin oxide is added....
wow, i really like the bottom bowls (well I like everything but these stand out to me)
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That's interesting. To me, the bottom ones take the most getting used to. If I don't manage that, I will just have to pass them onto you. ;)))
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