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TribeCreations

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About TribeCreations

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    http://tribecreations.wix.com/pottery

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    Birmingham, United Kingdom
  1. WOW ... those bowls are simply stunning Jo-Ann. I see you also take a generous amount away (cut/carve out) as I do. Do you have many that slump/warp after firing? What's the top temperature you fire these babies to in your glaze firing? They truly are quite beautiful.
  2. Oh WOW ... those yarn bowls look stunning! I think I'm being too extravagant with the cut-out design, but in saying that, there is a woman who makes similar one's and her's come out fine - no issues what-so-ever. Go figure! I also dry my bowls upside down, and only carve the shape out when its leather hard. I leave a bit on the top and middle to act as 'supports' as clay has a memory. When it's really bone dry, I remove those supports; or depending on the cut-out design, I bisque fire them with the 'supports' in and just grind down the bits with a tool - very time consuming though.
  3. Firing to maturity (or vitrified) temperature makes absolute sense for functional ware; you don't want your vase seeping water. Knitting bowls are not functional ware in the sense they need to be fired to maturity to hold water or liquids. Glaze firing to a lower temperature will reduce the likelihood of warping. The only downside is the lower fired clay will not have the hardness of clay fired to vitrification. But, for knitting bowls, your stoneware glazed at low fire temps might be the solution. Yes, good point - I never thought of it like that before. I will try a lower temp and do some tests to see which method works best. Thanks for your input.
  4. Thanks a ton Min - much appreciated. The bowls keep their shape even after I have carved them in their leather hard state, and even before they are bisque fired - none warp in the bisque firing. It's only in the glaze firing that they warp, which I can only presume its because of the high heat. I will run a few tests at different temps to see which works best. I read something today and it made total sense: "As anyone who has worked with clay for a while knows, a method that works for one potter, may not work for another". That pretty much sums it up! Chilly: ^06 glazes will give a good result ... I just fire to ^6 because I use stoneware clay and ^6 glaze. I think I should lower the temp and see what the result it. The thing is; I'm told that stoneware clay matures at 1230Ëšc to 1300Ëš and if I fire under that threshold, then the clay won't be properly vitrified - if that makes any sense!
  5. Can I ask another question please Min? What clay do you use to make your bowls? I'm having endless issues trying to find the right clay body that will hold up without slumping/warping. Do you have any 'slumping/warping' issues with your bowls at all?
  6. Well, thank you all for the helpful replies. The supplier I bought the kiln from suggested those firing schedules, and they programmed it in for me. They asked me what clay and glaze I was generally using, and they based the schedules on that information. So I presumed all was OK!? I dry the greenware out very well before bisque firing, so there's no way moisture can still be present. Before applying glaze to the bisque ware, I wipe each piece with a damp sponge (wearing surgical gloves) to remove any dust or debris. I then apply underglaze or glaze with a brush - ensuring even strokes, and not too thick either. I then leave the glazed items to rest for a day or two, and then I load the kiln and glaze fire. Reply to Diesel Clay: Yes, it's a 7 cone, and I agree, it's way too hot. I did make other yarn bowls with a thin 'upside down question mark' cut-out, and those even slumped too. I've tried many designs, and the majority slump. Reply to Min: Yes, I used a metal rib after trimming the pots to smooth out the bits of grogg. The glazes I'm using are all cone 6 (1222Ëšc/2232ËšF) - this is the top temperature I'm aiming for. My controller is programmed to reach that, but the cones are showing the headwork is going way over that. After chatting to many suppliers about which clay to use for the yarn bowls, it was suggested I use groggy clay, which I tried ... but it still slumped. I did try earthenware, but that too slumped. Reply to Celia: Now there's an idea - bisque firing upside down. Didn't think of that. I tried earthenware, but that slumped slightly too, and its more expensive than the stoneware clay I usually use. I'm very particular when preparing for glazing - I wear surgical gloves, wipe each item well, and ensure there's no dust or greasy hand marks on the items before applying glaze. I add water to the glaze to thin it out (single cream consistency) otherwise its too thick to apply. Maybe that's the problem - using water? If the glaze is too thick, it doesn't brush on evenly, so that's why I thin it out. Reply to bciskepottery: Good suggestion about slowing down the last 200Ëš. I will try and figure out how to do that and give it a go. I have done various cut-out experiments; from basic thin cuts to this extravagant one, and regardless of what clay I use, they all slump to a degree. So that leaves me to think it's the heatwork? Reply to MatthewV: Oh right, yes I see the weak point area. A few people suggested making the walls thicker than normal to possibly add strength, which is what I did. I did think about maybe creating an outward flared bowl as apposed to curved to see if that helps. I really don't understand why I'm having issues; when quite clearly, other potters are making yarn bowls with similar designs and cut-out's successfully.
  7. Righty-ho! A bit of an update and still confused; seeking input. Not sure if this is still the right place for this topic anymore? After chatting to the pottery supplier and showing them the yarn bowls that warped, and the clay that I used, they questioned whether my kiln was possibly over firing? To check all options, I got samples of about ten different clay types to see which would be the best for making yarn bowls - withstand warping. Two came out OK, but the others warped ... and they shouldn't have because its stoneware clay and can handle high temperates over and above what I fired to. Here's the firing schedule I used in my electric kiln which has a controller. Bisque Firing: 1st ramp: 90 degrees celsius - 600 degrees celsius 2nd ramp: Full - 1000 degrees celsius - soak 10 mins - Glaze Firing: 1st ramp: 150 degrees celsius - 600 degrees 2nd ramp: Full - 1220 degrees celsius - soak 10 mins - Cones used to measure the heat work: Cone 6: 1222 degrees celsius (melted) Cone 7: 1240 degrees celsius (half melted) Cone 8: 1263 degrees celsius (quarter melted) I put the cones on the middle shelf in the centre of the kiln. Attached is a pic of how the cones melted. This tells me the kiln is over firing, but to exactly what, I have no idea? And how to adjust the programme controller - I also have no idea what temperature to set it to in future? The glaze firing result: Most of the yarn bowls warped, glaze blistering/bubbles, holes, colours faded/darkened, uneven glaze distribution (even though it was glazed evenly). All the items are a waste Now, from the cone results, I presume the heat work in the kiln is higher than what the temperate is entered into the controller? Does this mean I need to lower the temperatures programmed in the controller? And if so, to what? I have no idea. I'm new to pottery and have absolutely no clue when it comes to kiln firing ... but I'm keen and willing to learn. So any input will be greatly appreciated. Sorry for all the pics, but I wanted to provide as much information as possible.
  8. Sure, no problem Anne. I don't mind sharing at all. Its Spectrum Cone 4-6 Bright Purple brush on glaze.
  9. Hi Min. Can I ask a question please? The colours you have used in your yarn bowls ... are they stains mixed with clear glaze? Spectrum underglazes on dry greenware, diluted a fair bit, thin but not drippy, 3 coats. I now bisque to ^06 since some of the colours flux at ^04. Clear glaze overtop. Super, thanks for sharing your technique Min. They look stunning. So what you're doing is almost like applying slip to greenware. Do you bisque fire the underglaze pot, and then glaze fire the clear on a second firing? Or do you do it all in the bisque firing? Sorry for asking so many questions ... I'm just curious to know.
  10. Not quite sure what you mean Chris? What area/s should be waxed? I cut the spiral out when its leather hard, and I usually leave thin clay bits in-between as supports, which I grind away after its bisque fired. After doing some reading, it seems a lower firing temp will be better, and perhaps I should think about using Earthenware clay as apposed to stoneware as it doesn't need to be waterproof.
  11. Hi Min. Can I ask a question please? The colours you have used in your yarn bowls ... are they stains mixed with clear glaze?
  12. Thank you Min. I will have a look at the thread link you posted. Marc - thanks for your input. Hmm, that does make sense. The yarn bowl I saw, that inspired me to have a go; was almost the same as mine - same amount of clay removed, with a big chunk out the top. But looking at the clay the person used, it looks like its got quite a bit of grain in it. Maybe I need to use a different clay?
  13. Hello everyone. I'm new to this forum - read many interesting posts and gained a lot of tips from many of you. Really nice to know there's a place to reference things, and hopefully get some help now and again. I'm also quite new to pottery. I have a wheel and kiln, and I make stuff purely for the therapeutic affect. Anyway, back to the topic that I need help with. I started making yarn/wool holders: basically a pot with a spiral cut out, with some holes (have attached pics). I used professional white stoneware clay, with a cone 6 glaze. When I bisque fired them, I noticed that some of the spiral bits warped. So when I bisque fired the second lot, I left clay support bits in-between the spiral area to stop it from warping. This method worked - I just needed to grind those bits away before applying glaze (as illustrated in pic). But sadly, after the glaze firing, all the spirals warped/collapsed. Does anybody know why? I thought that after the pots were bisque fired, they wouldn't warp again? Am I using the wrong clay? Or should the pots be higher with a narrower cut spiral section? Any input will be greatly appreciated. Thank you.
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