Monday, November 23, 2009

The Big One

The time has come;
I'm firing the first batch of crystal pots in my gas kiln. I reached top temp half an hour ago,trying hard not to let the kiln reduce [difficult when trying simultaneously to maintain a decent rate of rise of temperature],turned the kiln off,and have just relit it at 1080 degrees for the first 45 min. soak of six,each at a lower temperature. This is how I used to fire the crystals [for 20 years or so] until my old gas kiln couldn't take the strain,which just coincided with the time I learned to throw big[ger] pieces in porcelain. My small electric kiln has been a wonderful learning tool,and has produced some little gems,but it's small. I'm hoping that my new-ish gas kiln will give good results and justify the effort of manual firing - there are 4-6 hours now of sitting with one hand on the gas pressure tap making occasional minute adjustments to keep the temperature stable.
Only the top half of the kiln has pots in - the bottom is invariably too cold in an oxidised firing - and one of those is one of the sinks,which,as you are aware,are prone to cracking: I may have taken too long to reach temperature,or allowed a whiff of reduction to sneak in,either of which will wipe out the crystals: some of the tall pots were glazed with the charmingly-named fou-fou[a breath-powered spray] with which I have little experience,others in a tall length of plastic drain-pipe,both methods making the critical glaze-thickness hard to judge - in other words,I may well be wasting my time for the next few hours,not to mention the gas it's consuming. On the other hand,if my guesses and gambles pay turn out to be near the mark,we may see some fireworks tomorrow...

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