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Celia UK

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Everything posted by Celia UK

  1. Given the sharpness of (most) of this design it looks as if it may be done after the glaze firing (on glaze decoration). It looks like a white porcelain clay to me, with a transparent glaze. It would then have a 3rd lower temperature firing. However, it could possibly be as you describe, painted on white-dipped bisqued ware. Someone more knowledgable than me will probably chip in here with their suggestions.
  2. Sell for charity (individually/sets) at local art centre or similar potters' group. Do you have any charities supporting up-and-coming ceramic artists? eBay?
  3. From the album: Winter 2016

    Thrown white earthenware, linear additions, Holes carved then dots added. Wash of copper oxide and cobalt carbonate airbrushed when bone dry. Bisqued to 1000oC. Transparent glaze poured over, fired to 1100oC.
  4. From the album: Winter 2016

    Thrown white earthenware, linear additions, Holes carved then dots added. Wash of copper oxide and cobalt carbonate airbrushed when bone dry. Bisqued to 1000oC. Transparent glaze poured over, fired to 1100oC.
  5. From the album: Winter 2016

    Thrown white earthenware, cut and altered. Slabs textured and added. Copper oxide and cobalt carbonate washes when bone dry. Bisqued to 1000oC. Transparent glaze poured over, fired to 1100oC.
  6. From the album: Winter 2016

    Thrown white earthenware, cut and altered. Slabs textured and added. Copper oxide and cobalt carbonate washes when bone dry. Bisqued to 1000oC. Transparent glaze poured over, fired to 1100oC.
  7. From the album: Winter 2016

    Thrown white earthenware, cut and altered. Slabs textured and added. Copper oxide and cobalt carbonate washes when bone dry. Bisqued to 1000oC. Transparent glaze poured over, fired to 1100oC.
  8. My experience of low fire glazes is that they have quite a wide range, often beyond that stated. 06 fired to 04 - no problem with any of mine! It would have to be a very 'picky' glaze. But probably not worth risking anything precious without testing first, as Johnny says.
  9. Definitely can do this - I regularly fire both together. (Keep on different shelves!) Downside is that your finished ware will not be as strong as it hasn't been taken up to maturity. You want to find the highest your glaze can go to and try that! Good luck.
  10. My small kilns - 40 litre and 60 litre (less than 2.5 cu ft) are in the garage. I only ever run one at a time. Worst thing I notice is fumes around the 250-350oC (480-650 oF) mark. I'm not paranoid about venting and have none except normal garage draughts or sometimes leaving door propped open. However - I totally avoid going into the garage at the above temperatures because I suspect these fumes aren't good ones! (Think I may have read carbon monoxide somewhere, but I might have imagined that!) I wouldn't think they'd do much good inside the house, even if you're not working in the room at the same time. I think you'd want something extracting them out so they don't leak into the house. This is only my experience - for all I know they may smell awful but be safe enough.
  11. My advice would be to make some 'damp boxes' to store pieces from one week to the next. Large, lidded plastic box with about a 1" thick layer of plaster in the bottom. Several of these can stack and the work can be stored for weeks without drying out. Saves all that wrapping in polythene and spraying - I only discovered these after I retired from teaching and wished I'd known about them before. I have several in my home studio so I don't have to worry about pieces drying out before I can get back to finishing them. Google 'magic box for clay' and/or Tim See for YouTube video showing how to make. Red/brown earthenware is a nightmare to clean up and stains everything! I'd stick to clay if I were you. You definitely need some one session projects so that the students get to see results quickly - certainly in the beginning! It keeps them interested if they get to see a finished pieces quite quickly initially. They'll be happier to take longer over subsequent projects. Try every idea out yourself first - you'll work out the difficulties in advance AND have a finished product as a teaching aid and motivator for the students! Have an 'extension' activity/idea up your sleeve for students who whizz through at a record pace - there's always one! Don't underestimate the time it takes to clear up - get the students into good habits and be a good timekeeper yourself, otherwise you'll spend more time clearing up than you do teaching! Agree with the 'candling' in the kiln suggested above. The one and only time I had work 'explode' in the kiln was because I'd been in too much of a hurry and a piece wasn't completely dry. Good luck and enjoy!
  12. Oly - if you give Valentines a ring they're always very happy to advise. Similarly Potclays and Potterycrafts. I'm just firing some stoneware B17C to 1200oC with a 30 minute soak. I don't usually use stoneware, this was from a throwing weekend I attended a few months back. Hopefully they'll survive AND be leakproof as there are some mugs and a vase in there. Having read your post I'll definitely do a leak test before using any of them!
  13. Incidentally, where I have used this glaze but with addition of very small amounts of oxides (nickel and cobalt), I seem to have escaped without the crazing. Oxides definitely make a difference to the glaze formula - others will know if it's the expansion - that will be why they didn't craze. This glazing business is very frustrating....I sympathise Oly.
  14. I don't generally consider my pots to be functional because of the way I alter them - cut, distort, carve holes etc. but a friend sent me this photo of two pieces she won as prizes at the golf club. Quite ingenious to use plants that grow in gravel I thought!
  15. The COE of clay is significantly higher when it is immature: rather than vitrified. Silica primarily, but most all materials expand when heated until the flux melt begins to happen. COE values given for clay usually apply to the final product. Visual aid: A slice of bread is filled with air and expanded. When you press down in the center you force the air out: and the bread flattens to less than half the original thickness. Same thing is happening in clay: but not as dramatic. Nerd Not sure where your post (above) disappeared to Nerd - pasted here from my notification email! Thank you for the explanation - it makes me think a refire might well be successful. I'll try it for sure.
  16. Thanks Giselle - I like the idea of a 'secret' stamp - I could make something tiny that only I understand. Or possibly a tiny motif in an oxide perhaps? I'm on to it!
  17. Thanks all - I don't think I was clear expressing my thoughts! I'm sure the glaze will survive as I've fired it higher before but I was wondering if the the glaze fit would be better if the clay was fired to maturity - alleviating the pinging and cracking of the glaze. OR will the glaze fit be poor irrespective of the firing temperature? Would a slow cool help at all? Ann, I agree I've nothing to lose by trying - was just picking everyone's brain before putting them in with the next stoneware firing! I am trying to develop a system to ensure I keep track of which clay is which - labelled my damp boxes and shelves but it's when pieces go into the bisque firing that I sometimes lose track - my white earthenware and stoneware clays look pretty similar when they come out and even the feel is much same! I mostly use the white earthenware, but had some stoneware pieces from a throwing workshop lying around. JUST in case anyone was wonder how on earth I could mix them up!!!
  18. I've just taken a glaze firing out of the kiln - 1080oC (cone 04) transparent glaze on (mostly) a white earthenware clay. I can see that 2 pieces were in fact stoneware, which wasn't obvious after the bisque firing as my other pieces were white earthenware. The two stoneware bowls are pinging like mad and I can see the linear glaze cracks going round the bowls. The glaze can be pretty forgiving at higher temperatures and I'm wondering if these pieces might 'work' if refired to the clay's maturity temperature, or will the glaze fit always be a problem?
  19. Any kind of repetitive (new) exercise / positioning can bring this sort of thing on. Once it has settled, some stretching exercises and shoulder/ upper back mobilisation before you start throwing should help wake things up and prevent damage/tightening. I find Pilates to be brilliant for the older body - maintaining/improving joint mobility and strengthening where necessary to support vulnerable areas like the back & hips. In the short term a physical therapist might be able to manipulate the shoulder/ upper back and release things - physiotherapist / chiropractor whatever works for you. Good luck!
  20. I had the same problem a few months back Sputty - couldn't imagine what a sponge holder was. Not sure what I have by my sink that I'd put in one! Domestic goddess I am NOT. I've been trying to think of what would go down as well in the UK, a small item that everyone thinks they need. The only things I thought of were - used teabag dish and a spoon rest. Anyone got any other ideas?
  21. Yay! Not a crack in sight! Thank you all😀😀😀
  22. How I love this forum - wake up to find all this advice, it's great! I washed off the old glaze last night. The pot is drying off in the airing cupboard. I added a small quantity of sodium silicate to my bucket of glaze. First time round I did wipe the pot before pouring the inside - and NOW .... I'll try dipping a test tile as you suggest Babs and will dampen the pot by wiping again before a second pouring attempt. That means I've followed the advice of everyone above. Watch this space!
  23. Thanks Joseph. Do you know the UK equivalent of Darvans?
  24. I have just poured the inside of a stoneware cylinder (test piece bisqued to 1000oC) with a transparent glaze that crawled horribly in a previous batch. This is a commercially mixed dipping glaze - very reliable by all accounts! Following advice here and elsewhere I let it stand and drew the excess water off the top. The glaze is now like pouring cream consistency. 100ml weighs 153g. I've poured the inside - about 3 seconds. As it dried the glaze cracked - see photo. What does this indicate? Can I just finger-sand it and dip the outside or am I destined for more disappointment?
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