Sunday, 27 October 2013

Next firing.

I've been thinking about the next firing.  The shelves of pots are filling up a bit.

There are a few things there that I wanted to make more of.  The oil bottles and the hanging vases, for a start.  After the last firing, I knew some clays worked better than others.  The Svend Bayer clay worked very well.  Here's a mug, with a wonky rim - I've made another five, although they aren't as wide as this one.

I made a couple of large-ish jugs.  I am still a bit unsure about whether these are good or not.  I put them on facebook and some people said they're fine.  But fine isn't good enough.  I need to make money or won't be making any more pots, and there's no point in firing things that are just 'fine'!  But they'll probably make the cut.

I've also been making these jars.  They don't look much in the photos and are better in real life.  They are thrown out cylinders, and some of them have a texture added before I pull them in to a shape.  I quite like them.  I think the texture should take the soda well.

I have also mixed a clay body based on a slip I used in the last firing, that took the soda in ways I quite liked.  I threw a few small bowls and cylinders as test pieces, to put through out the kiln.  It's nice to throw with - looks alarmingly dark grey but should bisque to white.  I has the magic silica to alumina ratio of 2.7.

And the firing itself will consist of one of these two large pots (which I have bisqued already), the two jugs, and whatever else will fit.  It'll be a bit loose, but I don't mind at the minute.  Whether this is a good plan, I don't know, but it's what I've got.  None of the above pots are anywhere near dry, so it'll be weeks before I fire, probably.

Thursday, 10 October 2013

Soda Kiln - first firing.

It's fair to say I've had some issues with the new kiln.  I did one bisque firing, which went well, then started a soda firing, but had to abandon it as the temperature wouldn't rise past about 1000 degrees.

Well, on Tuesday, we started another one.  It struggled.  But eventually I got the temperature guage to read 1250 degrees, and I added 3kg of soda and soaked for an hour before calling it a day, tired after a 14 hour firing that had used an awful lot of gas.

Anyway, below are some results.  Reds and oranges were forthcoming from various slips - the high nephaline slip being the best probably.  It was hot at the top, cool in the middle and hot at the bottom.  I reckon much of the flame went into the kiln and then straight out the flue, with some travelling up to the pots at the top and then straight down the middle between the stack and into the flue, bypassing the middle shelves.  Put it this way, I have lots of new cat bowls!  But also lots of positives to work on, and a few things to discard (crank clay, even tempered with porcelain, isn't my thing - all those spots!)  Well, there will also have to be some kiln fixes made and some rethinking done.  But first, will need to make some more pots.

Tea pot with grolleg slip - not pretty but best lid I've ever made.

Bowl with shino liner - I like this one.  Toasty on the outside, soda on the rim, coolish shino inside.

A bowl I hadn't meant to put in, but which took the soda quite nicely.  I like the white dots from the molochite grog, and the liner glaze was the blue celedon, which went green, but hey ho.

A beaker, using the Svend Bayer clay.  This clay worked quite well.

Mugs - some better than others.  Spotty ones are crank - the really red one is the high nepheline slip and is lovely - favourite pot, probably.

 Another vase with the Svend Bayer clay.

Big pot with the grolleg slip.  The slip was peeling off though.  Shame.  I made this to make sour kraut.

This tea caddy is quite nice, but where the soda and the slip met, there was a green ash deposit which was starting to come off the pot.  I've seen this before.  Possibly too much soda on this pot.  It was on the bottom shelf, and I think bore the brunt of most of one burner as it entered the flue exit.