Red Hunt

A few days ago I was talking to another potter about RED glaze (which is notoriously hard to get) and that I had mixed up a glaze recipe described as tin red which turned brown during firing. She'd read that the ingredient chromium oxide which is to produce the red fails to perform if the temperature is too high. 

So I did another firing reducing the top temperature from 1260 degrees to 1240. The results were interesting:

Left hand cup: red glaze under cream. Right hand cup: red glaze over cream.

Towards the bottom of the kiln, the insides of two teacups turned kind of raspberry whilst the outsides stayed mainly cream (the other glaze colour I'd applied) even though the tin red glaze had been equally applied to half the insides and outsides of the cups.

Towards the top of the kiln, the tin red glaze applied to the outside of the pictured bowl continued to fire to a brown finish.

Cream glaze inside bowl and on outside rim. Tin red glaze on lower outside.

So what went on? Did the red inside the teacups in the lower part of the kiln come about because the temperature was lower? That seems to make sense.

But why is there only a hint of red on the outsides of the teacups? Did greater airflow around them interfere with the performance of the chromium oxide? 

Did the bowl that turned brown in the top half of the kiln do so because it was hotter up there? Were the firing conditions towards the top of the kiln more like those during the previous firing which only yielded brown results? I wished I knew the answers!

Whilst I continue to scratch my head, I am rather chuffed with the colour I've managed to get. Fingers crossed, I can do it again!!!


Sculpture Courage

I first got my hands onto clay during art classes at school. One of the projects was to make a mask. I tried to model it on my dad. It ended up looking like the face of an Indian - no family likeness whatsoever. I've often been on the verge of flinging it in the bin. One day I probably will but I thought I'd show it here to illustrate a potter's sad first effort.

I much prefer the sculpture my son made at primary school. 'What is it?' I asked as he brought it home. 'A monster', was his reply. Stupid question! It also stands in my bookcase now - in a much more prominent position. Its future is secure unlike that of him above.

Today, I primarily throw on the wheel. I shy away from making sculptural pieces. Maybe because of that dismal early effort. I did have a go at a couple of raku birds.

Not my last attempt, I'm sure. I just need to pluck up new courage ;)))


glaze mystery

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 :))))


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