Showing posts with label pottery glazing. Show all posts
Showing posts with label pottery glazing. Show all posts

Sunday, January 20, 2019

Studio time...


We've had a busy past few months, and our fair share of ups and downs, but just this past couple of weeks or so, since Christmas and the school holidays, things seem to tentatively be looking up. It's still too early, too fragile, to think much of this in the long term, because we've been here before, and this is bug season, and the school term has only just begun, but we are feeling hopeful and just a little lighter, so we are trying to just enjoy this for now.

In the spirit of this uplift I've clocked some much-needed pottery studio time. I've been dreadfully slow with this, because I knew my next task was glaze testing, and there always seemed to be some reason or other to delay - it was too cold (but my new heater is in now, so this is not an excuse anymore), I didn't have enough time to get started (mixing glazes is time-consuming), I am still waiting for some glaze component or other to arrive in the mail (it's amazing how much stuff you need if you are testing, because there are so many different ways of putting together a working glaze), my studio is too chaotic (this was a bit of an issue for a while, because stuff had migrated in there on a temporary basis, but it's mostly sorted now)... So many excuses!


There are still fairly important things to sort out to make my little studio space work - I don't have a source of running water, so that is an issue,  because I don't like the idea of bringing potentially toxic pottery materials into the house via brushes or buckets. We are now considering installing a washing-up sink outside with a trap to catch heavy particles that I don't want going down the drain. Hopefully this summer...  I also need to repaint the concrete floor in my pottery space, because it's crumbling and therefore generating dust. This also does not allow me to mop the floor, meaning that any spillages will also dry and generate dust, which is a potential health hazard, particularly long-term. I also want to paint the brick-work on the walls because I get so much dirt falling down and contaminating my work space.

That said, it's a good little studio by now. My lighting is sorted out, and I have my awesome little heater, which means I feel less like an extra from La Boheme when I'm working in there at any time other than high summer.

I've even managed to get some of the dreaded test glazes mixed up the other day and I managed to pour only half a bucket of glaze over myself. I call that a win!

Now hopefully one of these testers will generate the glaze that I'm after, because I'm still struggling with that. I want a pure white glossy glaze that covers well and doesn't break over the edges of the little houses that I make. Once I've achieved that I want to make a big badge of glaze and create enough houses to put on Etsy or Folksy to sell so my pottery endeavours become a bit more cost-neutral at least.



I even managed to motivate boy #2 to help me paint the planters that he got for his birthday so they can be moved out of my studio onto the patio. Boy#2 is our green-fingered child, and he loves planting things, so we are hoping to grow some vegetables in his new boxes.
 

Wednesday, September 12, 2018

Glaze Firing...

It's been a long time since I've done a glaze firing. I did a couple of biscuit firings but that meant that things were really piling up in the workshop and I was pretty much running out of space to even put things down. I needed to get on with it and glaze some things so I could make some room, you know? 

Glazing is not my favourite task. I obviously love the look of nicely glazed ceramics, but it's such a fiddly job, and so prone to going wrong, that I dread it just a little, because the danger of ruining a much-loved item is so very real. 

Take that, and add to it that glazing materials are hazardous and best not used around children, and you've got the perfect playground for some heavy procrastination. ;)    It's taken me months to get to the point where I could shut the heavy kiln door and programme my controller.

That said, once it's done and everything is loaded, it's all very exciting. A kiln firing takes a good 12 hours, and after that it takes another 48 hours or so for the kiln to cool down to ambient so it can be opened safely and without danger of cracking any pottery or glazes due to thermal shock. That's a whole lot of nervous waiting, because you never quite know what you are going to find once you crack that kiln door open - is it all going to  be shattered, or will it have worked?!

This firing was to stoneware,1220 degrees C. I switched the kiln on at around 8am in the morning and because Betty is quite an old kiln I checked on her several times that day to see if she was doing her job. She was, and by the afternoon when I checked once more, there was the tell-tale glow from the air hole at the top where I'd removed the bung to help the kiln breathe. Can you see it? 


Closer look...


The temperature at that point was 1147 degrees and rising.


It's always fascinating to me how the inside of the kiln starts to glow once it gets to the really high temperatures. This is the glow through one of the ceramic bungs in the door, which, by the way, are not normally transparent. 



Betty reached temperature at around 8pm that evening and then started to cool down. It was a loooong wait, because after the initial fairly quick drop in temperature down to around 600 degrees, which she managed overnight, things slowed down and it took a further day and a half to get to around 45 degrees, at which point I couldn't take it anymore and cracked the kiln door open. It was still a little early, and there were a few ominous pings (that's the glaze cracking...), but nothing too dramatic happened, and I don't have anything in there where a few minor cracks in the glaze should matter in the least. 

I forgot to take a shot of the kiln right when it was opened, so in this picture a few items have already been moved. 

 

Overall it was a  very successful firing, but a few things did go wrong - right on the top shelf I had a big plate that I had glazed in white, with small chips of blue glass to melt in all the little indentations in the plate. That part went well, but apparently I had not taken off enough glaze at the bottom of the plate and the whole thing got stuck to the kiln shelf and, because it couldn't expand and contract the way it needed to during firing, cracked in several places...



Ah well, you win some, you lose some...

On the other hand I had a few things that turned out quite lovely:










I think, overall, I'm pretty pleased with this glaze firing! 

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