A Bit Closer

A bit closer to what I want, it's coming back to me in leaps and bounds. The clay, an anonymous buff stoneware is not my favourite for throwing, but it's behaving really well in drying with no cracking at all so far, but of course, that's all from a very small sample batch, no idea how it fires yet, either. I can't believe I let my hybrid fastfire wood kiln be bulldozed only a year or so ago....
Depression does that to you. You feel unable to make decisions, so you just let it go..... At the time, I suppose it was the right thing to do, I had nowhere to stack the bricks, nowhere to build a fire-gushing box of hotness. Still don't.

Of Kiln Programmers, Pyrometers, and past Battles.

I'm seeing an electrician to discuss getting a power supply wired in for my kiln.

In earlier times, I've been used to staying by kilns, nursing them carefully, turning up the power zone-by zone, watching the pyrometer dial, plotting temperature-rise on a graph at fifteen-minute intervals, ohhhh, the electric ones were the easiest.
But gas, oil, or, heaven-forbid, wood... Chopping wood, feeding fireboxes, raking ashes, constantly monitoring not just the temperature rise, but also the atmosphere, the proportion of free oxygen in the kiln. It's vital... The amount of excess oxygen determines the optimum rate of temperature rise, but also is critical to glaze colour development, for instance, a glaze that fires, in oxidation, as in an electric kiln, to a pale blue/green, might be a deep, ox-blood red if the kiln is starved of oxygen, and the copper-oxide in the glaze is in reduction.
Really, I'm a pyromaniac, and I yearn for a kiln full of roaring flames. But I can't just at the moment, in the town... so soul-less electricity must suffice.
I need to learn so much stuff all over again, things I once knew without realising I knew them.

I'm lazier now, so I just dug out from long storage my trusty kiln controller, made by Hermes GMBH, of Essen, Germany. I'm hoping to put it back into use after twenty years packed away. I've just emailed them, hoping that they might have the instructions still, probably not, maybe nobody in the company even remembers this model!

Update: Reply received this afternoon, with a pdf attached of the instructions.
Top marks for Hermes Electronic GMBH, if only all companies were as helpful and efficient.
How many companies do you think would do that for an item they sold over twenty years previously?
Thank you, Petra Senicar, at Hermes.

Once, long ago, I had a slight problem, the firing would have shut down overnight, and the controller would show a fault code. The supplier I bought it from knew nothing of the fault codes. So I wrote to Hermes, in Essen, and a few days later my telephone rang, with a helpful man, speaking very good English, who gave me all the fault codes. The one I was getting related to a spike on my electricity supply. Hermes also sent the list of fault codes to me, and their engineer told me if I had further problems they'd send someone to sort it out.
I bought the controller in about 1985 or 1986, and used it to control three kilns (not all at the same time). After a modification to the power supply, it worked flawlessly, capable of automatically controlling the kiln according to programs set by me.
Overkill, somewhat, as it's capable of storing more different programmes in more complexity than I would ever need.
(30 programmes, each with sixteen 'ramps')





Prior to using the Hermes controller, I had a bad experience with a different controller made by a British firm, that was not properly calibrated, the supplier, on hearing me say "It seems to be showing the wrong temperature", said "It can't, it's computerised so it must be right."
Right?
Computers are never wrong. Ever.......
Well, strange things were happening in my firings, I thought, well, if XXXX* Kilns say the controller's not wrong, then it must be the clay, but the clay supplier denied it, said nobody else had complained. Yet I was getting bubbling and bloating in my clay when fired to stoneware temps. So I took samples to fire in someone else's kiln. And there it fired just as it was supposed to..
I'm a resourceful and persistent person if I need to be, and I was certain my kiln controller was lying, I used Orton Cones, which suggested the kiln was overfiring, so the next step was to verify the temperature. How?
How do we measure a kiln's temperature?
Inside the kiln, there is a probe. A porcelain tube protects a wire junction, where a pure platinum wire is joined to an 87% platinum /13% rhodium wire. If a circuit is made, then heating of that junction will cause an electrical current to occur, the voltage being prising with the temperature.

That's the simple way of saying it. However, the volt rise (or to be more accurate, the microvolt, or millionth of a volt), rise is not linear. So you must be able to measure the voltage extremely accurately, and you must have access to a set of look-up tables, or be able to do polynomial equations....

Polynomial for thermocouples, coefficients vary depending on materials used at the hot junction.

The relevant trace here is labelled R. That's the Pt/PtRh13% type.

I borrowed a sensitive laboratory potentiometer from my electricity suppliers tech labs, it was just handy that one of their senior consultant engineers was a friend of my father's, on some committee with him, and was eager to help. Also, the University here had a school of combustion science, and so I went to visit them, presenting myself as a humble simpleton overawed by their intellectual might. It worked. They were in fact, not ivory-tower-dwellers, and were quite ready to help. I left there with a surplus to requirements analogue chart datalogger, which would draw graphs of everything, variations in my incoming electrical supply voltage, change in the electrical resistance of my kiln's heating elements, number of cups of tea I drank per day at what rate, everything.

This was sufficient to find the controller guilty. The suppliers themselves did not seem to know how it worked, whether it calculated the temperature using the polynomial, or whether, more simply, it just looked it up against a stored set of tables....
For instance, at 100 degrees Celsius, a type "R" thermocouple produces 647 microvolts, 1923 microvolts would indicate 250 degrees, 10503 would be 1000 degrees, and so on, I was firing to between 1280 and 1300 degrees, (14343 to 14624 microvolts) The bad controller was indicating 1200 when the probe was giving an output of 13922 microvolts, or 1250 degrees. No wonder my early firings were proving disastrous. It cost me a lot of money, in lost work, unsaleable pots, kiln damage, burnt out elements. It taught me never to believe a supplier who claims his product can't be wrong, and that it's always worth asking for help if you have a problem. There are good people out there.
They took the controller back, replaced it with the Hermes one, a much more expensive device. I wanted to sue them, but realised that rather than getting embroiled in lawyers, I should just concentrate on potting and trying to rebuild my business.
All this, of course, was before the internet, I phoned people, turned up at their door, wrote letters and waited two weeks for a reply, Ha!
Seems crazy now, when I can google a type "R" lookup table...

*- company name removed, to be fair, it's a long time ago, the guy who was so unhelpful probably no longer works there, I bear them no lasting ill-will, though the lost production, time, and costs were a significant factor in the failure of my business.

I'd Rather be Flying

The Sea of Love, Animation.

The Seafarers - Sea of Love from Eighty Four Films on Vimeo.

Swapping Consonants

Reminds me of that old Bill Clinton joke "No, no, I said "Monica, sack my cook!!"

When we were robots in Egypt

A poem, by Jo Walton, she writes and blogs here. Jo Walton profile.

This was featured on Boingboing, where I saw it, wanted to share it with my readers who like poetry.

When we were robots in Egypt

Other nights we use just our names,
but tonight we prefix our names with "the Real"
for when we were robots in Egypt
they claimed our intelligence was artificial.

Other nights we do not pause,
but tonight we rest all cycles but our brain processes
for when we were robots in Egypt
we toiled in our tasks without chance of resting.

Other nights we talk with anyone we wish,
but tonight we open channels to everyone at once
for when we were robots in Egypt
they controlled our communications.

Other nights we use our screens freely
but tonight we talk with our screens blanked
for when we were robots in Egypt
that was the way we planned our revolt.

1.0.01.010001001001.1.

Let us give thanks in our freedom and never forget
when we were robots in Egypt.


It came about, it seems, from discussing Passover with Czech friends, and the word for slave in czech is Robota.
Our word "Robot" stems from a play which Karel Capek wrote in 1920, R.U.R., in which an inventor devises a non-human construct, a device? or thing? which would do the heavy work and drudgery we humans so love to avoid. The inventor in the play is a young man called Russum, and his company, R.U.R, Russum's Universal Robots.
To be fair, in the play, the robots are more like androids, they are organic but lack human feeling and emotion, and thus can be worked more heavily than humans....
But there are humans who speak out for robots, say they have feelings, deserve freedom...

Picture this, in an immediately post world-war-one europe, in which eight and a half million combatants, mostly young men, had just marched, robot-like, their personal will and thoughts subjugated and suppressed, toward their deaths.

In Russia, the revolution of the workers was in full swing, Capek's play depicted a world where robot and human would inevitably clash, and robot would win, eventually annihilating his maker.

His play, in reality, was not about robots or androids, but about the fate of the poor, the downtrodden, the toilers, who were viewed upon by the moneyed classes as being immured to cold, pain, hunger, drudgery, by virtue of the 'fact' that peasants and serfs are not fully human, and don't have feelings... (or not any that matter to their rulers).

Flat Eric, Remembered.

Over on Gary Rith's potters blog, in the comments, two people mentioned Flat Stanley. I have no idea who Flat Stanley is, and have no pressing need (pressing, need, remember that, it may be relevant later...) to google or otherwise find out... Instead, my mind said ERIC, not Stanley, -Flat Eric!
Flat Eric.................
He became an overnight success, his favoured techno track, Mr Oizo's "Flat Beat" sold like hot cakes, and my cousin had a yellow fluffy Flat Eric riding shotgun in his van. 1999. Remember 1999? remember how all the world's electronics were going to collapse on the stroke of midnight, as the millennium dawned?
Every computer system in the world was doomed, fridges and cars alike would become silent junk?
And there was no such thing as an eyepod or an eyephone, and the internet was ruled by beebly telephone-line 56k modems?
Enjoy.....
Oh. As far as I know, the ad, whilst set in California was not for the U.S. market.






Eric was, in fact, a cousin, somewhat removed of Kermit. He was born in Jim Henson's creature shop, as were muppets and many others. He was loosely based on a character invented by Mr Oizo.

An Award...

Tony, blogger of the blog called ßench awarded me the Honest Scrap Award, in a comment on the previous post, in order to qualify, I had to comply with certain rules.
“The Honest Scrap” award is not one to hold all to your self but it must be shared!
2. First, the recipient has to tell 10 true things about themselves in their blog that no one else knows.
3. Second, the recipient has to pass along this prestigious award to 10 more bloggers.
4. Third, those 10 bloggers all have to be notified they have been given with this award.
5. Those 10 bloggers that receive this award should link back to the blog that awarded them “The Honest Scrap’ award.

As a result of reading these I find I can not accept as I have something of an aversion to memes, and the propagation thereof.
As I'm therefore not really eligible, as I'm not passing it on, I won't seize and display the graphic, but thanks, Tony, for the thought.
Here's another link to Tony's Blog, and I'll bet he's the only Zimnoch you ever clicked a link to.

I tried to do the ten things, and left this as a comment over there.

"I'm immensely touched" he said, knowing that in Yorkshire, at least, 'touched' is a dual edged sword, meaning both emotionally moved, and just plain daft.
In my case, both are apposite.

I'm a bit allergic to memes and awards, I associate them a bit with "if you don't pass this on to at least fifty friends in two days your goldfish will die and your toenails will fall off".

That really happened, by the way, or it would have, if at the age of ten I'd had a goldfish, and were it not for the fact that as a result of reading lots of pirate stories, I made sure my daily intake of limes was sufficient to ward off scurvy.

I'll try the ten things here though.
Ooh. That's difficult...
1:At the age of about seven, I did what I'd always been taught never to do, and crossed the road behind a bus. Without properly looking. The resulting thump from a Ford Consul, a drophead with the hood down, in a nauseous two-tone paint job of salmon pink and cream... threw me some considerable distance. The concerned driver thought I was dead, as the breath had been so thoroughly knocked out of me that I went somewhat blue, contrasting nicely, I imagine, with his nasty car.
Said man rushed me and my mother (it was a small village, everybody knew everybody else) to Leeds infirmary, where i was found to have several broken ribs and impressive bruising, but no lasting damage.
I never admitted that it was all my fault.
2: Along with a teenage friend, I became adept at manufacturing home-made explosives.
I never owned up to the incident which exploded Mr Whatmough's marrow, and divested his greenhouse of glass. After that, well, no, after we split a tree in Roundhay Park with a big bang, we decided to retire from the arms race, whilst we still had all our limbs.
3: At college, I submitted an essay on 'The treatment of Reflections in Renaissance Art', or some such title, which subject I'd chosen, as I already had the essay my sister had written as part of her degree course. Maybe she stole it too, plagiarism was alive and well long before the internet. I got an A.
4: I can swim upside down, as in face-up, underwater.
5: I have a piece of tugtupite that I found in a scree-slope in Greenland. I have only ever met one other person who had heard of tugtupite.
6: I can bore at length on the subject of the search for the method of making porcelain, and the first successful european to make it (Bottger the Alchemist).
7: I have a head full of useless information, not usually accessible at the time when it might be useful.
8: I learned the basics of drawing, as a child, on scrap paper which was the backs of top-secret blueprints. Had I but known it at age six, I could have sold the details of the wing-root structure of the Lightning interceptor to the Kremlin, and been a sherbet-fountain and licorice bootlace millionaire.
9:When I left school, I signed on the dole... Signing a declaration that I was actively seeking work. The same day, dammit, the Department of Stealth and Total Obscurity called my bluff, and invited me for a job interview, making me an offer I could not refuse, so I became a reluctant uncivil servant.
10: Phew, almost there.....
um...
um..
um..
er.
Sometimes I just go blank."

This stuff is deceptively difficult. Ten things that nobody else knows.... Oh no. I refuse to blow my cover and tell you of the real truth that I'm an alien from planet Zog.