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Celia UK

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Everything posted by Celia UK

  1. Glaze firing on - mostly transparent over oxides and tissue transfers with my v reliable glossy glaze. On the shelf is a batch of stoneware pieces from a throwing workshop I attended - after 2 failed stoneware glaze firings I'm very reluctant to get on with these. Have tweaked the glaze and will do just one test piece before sacrificing the rest to the kiln gods

    1. Celia UK

      Celia UK

      Current firing is white earthenware - didn't make that clear! I too am no lover of glazing - after various disasters!

  2. [What temperature do you fire to, so I can be a bit more specific? Are you against lead because of risks to yourself? If you are doing functional ware then you can keep the lead out of the area in contact with food - e.g. on the outside of jugs - and use a lead free glaze inside. Or, so long as you don't use copper, you can make food safe lead free glazes - you can get the same lead leaching test kits on eBay that the FDA field workers in the US use (I forget the name, the seller is somewhere round Poole), or if you do a lot it is only about £40 to get a test house to do a more accurate and official test for you. Thanks Tim - glaze firing to around 1100oC. I appreciate that I can keep the lead glaze to the exterior, but I do like copper!!! I'll look for the leaching test kit - worth knowing about thank you! I've been to the ceramics suppliers today and talked this lead issue through with various technicians - then priced up the ingredients cost and there was little savings to be had over buying one of their glaze mixes! The only benefit seems to be that you know the exact contents if you mix your own, which is helpful if things don't turn out well and you're then trying to troubleshoot. Sputty - don't think I'll need to worry about EU regulations - one of the few benefits of being 'out'!!! I'm going to try an alternative recipe that Gerry at Potterycrafts suggested (using ingredients I already have) and see how I go! Re AP - the recipe above was from a glaze workshop I did with John Masterson (AP Chairman), who, along with most others I've spoken to would similarly not be overly concerned if used on outside of ware and suggested testing if I wanted to seek reassurance. Interesting comment about endocrine disrupters - especially as one ceramic supplier expert tells me that Lead bisilicate has been removed from the list of toxic substances - can't remember the name, but it no longer bears the skull & crossbones symbol, but food standards have apparently yet to catch up. I expect that will promote a flurry of posts here!
  3. I have a low fire transparent glaze recipe that makes a nice glossy glaze with a good colour response to various oxides. It has crazed slightly and would be even better for me if that didn't happen. I know the lead bisilicate helps with the colour response but am not sure about sticking with this as my 'go to' recipe because of the lead. This is for use on a smooth, white earthenware, sometimes just as a transparent over underglazes or oxide washes, but also as a base with oxide/stain additions. Can anyone suggest a possible substitute? And if it helps with crazing that would be even better! I know I'll have to re-test, but a starting point would be helpful. The recipe is - Lead bisilicate 65 Whiting 10 Potash feldspar 15 China clay 10
  4. In my experience you still have to dremel off the 3 points from the tripod ceramic stilts. One potter I know, teaches students to put 3 small dots of wax on the base, for the 3 stilt points to rest on. This stops the stilts fusing on to the base and you are left with 3 neat unglazed dots. Trickiest thing is to align the stilt on the dots and then place it all on the shelf without moving the stilt. Works if you can do it!
  5. So you win some and you lose some Oly - at least you have a functional pot now!
  6. Celia: I find it very hard to believe this clay matures at 1200C [ 2192F] The silica % is lowered, which is the usual protocol for cone 10 to prevent dunting due to free silica/cristobalite formation. The alumina is on the low side as well for a stoneware body- more in line with earthenware. The primary flux is potassium: which is in line with cone 8-9 range. Some comparisons: Generic C10 stoneware body: 64.97 silica, 28.31 alumina, total fluxes: 3.71 >> I would estimate the maturing temp of the body shown above in the cone 8-9 range at minimum. (total fluxes 3.81%) Iron can only be counted as a flux if it is fired in reduction. Nerd It was Scarva's reply to a customer's question that said it matures at 1200oC - I didn't find that anywhere else and haven't heard it from Vaentines. With my limited knowledge, the ingredients mean absolutely nothing to me, but I guessed it would be informative to some of you out there! I have to say, I always thought of a firing 'range' as the range within which it would be 'cooked'! - mature from the lower temperature upwards with a risk of melting beyond the upper! Even if there is a wide range, also giving the maturing temperature would help - or does this actually depend on heat work rather than actually being a fixed point temperature???? Why is it that in the UK clays and glazes are given temperature ranges and in the U.S. are more often given 'cones'? With the digital controllers on both my kilns using degrees centigrade, I have an ongoing mental exercise getting my head round the correlation between temperatures and heat work (cones). I've got all the charts and so know the theory, but then, there's what my kilns actually do..... I've been quite envious when reading posts that say e.g. 'I programmed my kiln for Cone 5 - 'fast''. Makes it sound so straightforward.
  7. I don't think it's the same clay as schoolware buff Joel. Scar a says ES5 vitrifies at 1200oC. It's a very popular clay amongst Anglian Potters Association - around 400 members from hobby potters to professional. We have 3 clay stores across the region and buy in bulk for our members and this is one of the best sellers. Not sure if the composition tells anyone with the knowledge any more about it:- 64.84% SiO2 1.05% TiO2 23.57% AL2O3 0.75% Fe2O3 0.08% P2O5 0.22% CaO 0.31% MgO 2.57% K2O 0.72% Na2O Total contraction at 1200oC - 13.80% Thermal expansion 500oC - 0.260 600oC - 0.320 But no absorption listed.
  8. Ring dishes. Don't need the heart shaped hole - these are wedding favours that will have a name tag! Thin slab, cookie cutter, something to add textured feature. Or roll out slab on a texture. Easy peasy!
  9. +1 on NOT having canvas. It really is about breathing in the dust (though also produces far more than you'd imagine which settles on all your flat surfaces, jars, containers etc. and just makes for a mucky working environment.) I work on a wooden table - surface has several coats of satin varnish. I use small ware boards and pieces of dry wall for building on and a plaster slab for wedging & rolling.
  10. Definitely get back to the supplier - Shimpos are known for their quietness and this definitely sound faulty. They SHOULD offer straight replacement.
  11. It depends on how detailed the designs are. Some very detailed stamps, with little space between the lines will only give a very superficial image (2 on the left of the photo). Bolder, more 'open' designs work well (2 on the right).
  12. Thank you! Will take a look in Sainsburys next time I'm in town. Molasses also not something I've seen in UK.
  13. Karo syrup? Anyone know a UK equivalent?
  14. Ditto - even to my inexperienced eye!
  15. Visiting Kingsbridge Devon this weekend any UK potters nearby up for a visit?

    1. High Bridge Pottery

      High Bridge Pottery

      Only if you're going via Newcastle!

       

    2. Celia UK

      Celia UK

      HaHa! Joel - with a 5 hr drive in the opposite direction - I think not! You still working from home? Got a shed in the garden?

  16. I've known underglazes flux too - a friend was most surprised at the shine on her 'bisqued' pieces with blue underglazed surface. I suspect your bisque went a bit high. There seems to be a narrow margin here.
  17. Posted Yesterday, 03:14 PM Your setbacks (Spacing) are more than you need for both kilns. It will not hurt anything but it does waste space. I would raise the test kiln to a hieght that is easier to load a well +1 for Mark C's post above.
  18. Sorry...no idea what a k cup is and don't really recognise it in the photo! With the clue from Joseph, above - is it a coffee pod for a coffee maker?
  19. Hugs across the miles Evelyne. It's a really tough time but you're doing an amazing thing for your loved ones. There will be better times ahead. X
  20. Stuff everywhere at the moment - I say I'm multi-tasking but you could say I currently lack focus! Testing letter stamps for my niece's wedding favours (130 different name tags to go on the heart-shaped dishes in the 2nd photo). Green ware waiting to go into the kiln. Bisqued pieces with tissue transfer decoration waiting to be glazed... Plus 3 damp boxes of thrown bowls - 1 more to trim, then decisions re decorating all 9 bowls. This is quantity for me Mark!
  21. ah Babs - now I read that as the bottle had been used as a spray bottle - to spray water....Never occurred to me that JonesAK might have used it as a former. Let's see what comes back.
  22. Celia UK

    Creamers

    Thanks Min - will post again once glazed and fired. Think I need to be a bit careful with this one, as my original image was based on an Orla Kiely print!
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