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Claybot

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  1. Awesome! That's just what I was hoping for, but a thousands times better. Thank you!
  2. Haha, I love the bolded red "no." I followed your link; that book looks great. Bookmarked for purchase. Regarding my grog question, after accidentally clinking my pots together a few times, I discovered that my whitish earthenware pots chip too easily. So I switched to terracotta earthenware after having heard that it was the toughest, most chip-resistant low-fire clay. It does seem tougher, but I haven't clinked any pots together lately to find out. Then I read here that having no grog makes fired terracotta more chip-resistant than having grog. Then an experienced potter contradicted that info. She said that grog makes ceramic tougher, like straw in bricks. So...I don't know what to think. Maybe grog makes no difference?
  3. Thanks for answering, Chris Campbell. Yeh, I meant kiln shelf. I had a feeling that I didn't need to use the kiln wash, so I'm happy to know I can stop. Yay, no more going outside and sanding white powder onto the lawn. Ah, I bet that was the problem. My kiln wash was very thick. Regarding grog strengthening or weakening the clay, I read on this forum that grog weakens clay. But then an experienced potter told me it strengthens it. I'm guessing it weakens it, as nobody corrected the person on this forum.
  4. Do I need to use kiln/bat wash on a bat if this is my process: fire my dry greenware pot; paint the pot with underglaze; fire the pot again? I thought maybe the kiln wash on a bat might only be necessary if a pot was covered with glaze, not underglaze. (Low fire clay and underglazes, if that makes a difference.) If a bat already has kiln wash on it and my pots are only underglazed, never glazed, do I need to sand the bat after the underglaze firings and paint on new kiln wash? I imagine the bat would eventually be covered with lots of rings if I didn't, like coffee mug stains, but is that a bad thing? (Low fire clay and underglazes, if that makes a difference.) If I wipe the kiln wash on my bat with my hand, a cloud of powder puffs into the air. Is that normal, or did I do something wrong when I mixed it? Which is harder and less susceptible to chipping: clay with grog or clay without grog? If the answer depends on the clay, then low-fire terracotta clay. Thanks for your help!
  5. My self-supporting cone should not have bent over to the 4 o'clock position? I don't understand. To summarize and add some extra information: My self-supporting cone is 2 1/4" tall and is for temperature 04. My pyrometric bar for the kiln sitter is 04. My box of clay reads "RED CLAY W/ GROG C/06-4." I wanted the kiln to get to 04 hotness because I used 04 underglazes. The witness cone bent to 3:30, indicating that the kiln didn't get hot enough. Also, as far as I know, I can't fire by temperature because my kiln has only a kiln sitter. Thanks for posting. I didn't know there were different sized witness cones with the same numbers that do not coordinate their temperatures (which doesn't make sense to me).
  6. I read the PDF. Yikes. I don't like the idea of parts of my eyeball heating up. I'll stop looking through the peephole until I get some goggles.
  7. Thanks for the extra information. I have so much to learn. This forum is such an excellent resource for inexperienced kiln-users like me because of people like you and all the other posting potters.
  8. Thanks! Why safety glasses? Can looking through a peephole be any more dangerous than looking at a glowing element in an oven? I've heard this a couple times now and don't understand the need for caution.
  9. Hm. After reading your post, I did some research. I think I placed the pyrometric bar too close to the kiln wall on the two support prongs, where it's extra-hot. I'm going to place the next bar outward a little, level with the edge of the prongs, and re-fire the pots. Hopefully that will get me the correct angle on my next witness cone. If that doesn't work, then I'll try a one-increment-hotter bar for the kiln sitter, like Chris and Pres suggested. Thanks for all the help!
  10. Hi. I fired underglazed earthenware bisqueware in my kiln to 04 hotness. Unfortunately, after my kiln had cooled and I looked inside, my 04 witness cone had bent only to a clock-angle of 3:30. It should have bent to a clock-angle of 4:00 at minimum, according to Ortonceramic.com. It typically takes 15 to 25 minutes for a cone to bend, depending upon the cone number. The cone bends slowly at first but once it reaches the halfway point, it bends quickly. When the cone tip reaches a point level with the base, it is considered properly fired; however, the difference between a cone touching the shelf and a cone at the 4 o'clock position is small and rarely affects the fired results . To make sure my kiln heats to 04, should I start using an 03 pyrometric bar under the kiln sitter's actuating rod, like it mentions below (also from Ortonceramic.com)? Is there a downside to that solution? The Kiln Sitter® shuts off the kiln when a small cone (or bar) placed under the sensing rod receives enough heat for it to fully bend. Bending is caused by the weight of the sensing rod. Because the cone in the Kiln Sitter® is located at the kiln wall (closer to the heating elements), it frequently receives more heat than witness cones, causing the kiln to shut off early. Using the next hotter cone/bar may be necessary. One more thing: my kiln has no timer, just a kiln sitter, so I can't add extra minutes to a firing. I'm assuming adding extra minutes would solve this sort of problem. Thanks for any help!
  11. Thanks, pottery people. I am going to abandon my five ugly pots and move on. And I deeply appreciate all the excellent reasons given for doing so.
  12. Hi. I have a few pots that were ruined by dipping them into too-thick clear glaze, matte finish. The glaze pooled in the pot's decorative textures during firing and now the recesses look milky - like the pots were dipped in a watery Elmer's Glue. The pots were fired again in an attempt to reduce the milkiness, and re-firing did help, but the pots still look terrible. I like using 04 underglazes. Can I paint underglazes over the milky clear glaze and refire the pots, thus hiding the milky clear coat? Each pot took about a day to fashion and I really want to rescue them. Or should I refire the pots again and maybe again, and hope the milkiness diminishes enough to the point where the pots look okay? Is there some other solution better than the ones I mentioned? Can anything at all be applied over a clear coat? Or is a clear coat the final step in the pottery-making process, like varnish on an oil painting?
  13. Thanks for the helpful replies. By the way, I'm going to start marking the cone on my bags of clay with a Sharpee before de-boxing the bags. Another potter told me she does that. Also, tragically, I can't find my receipt for the clay. I searched for it before making the thread.
  14. I thought my clay was 06 earthenware. I made some pots, let them dry, painted them with 04 underglaze and fired them at cone 04. The bisqueware pots seem okay and normal. However, I'm new to firing clay and when I bought the box of clay at a ceramics supply store a couple months ago, I think I may have mistakenly asked for stoneware instead of earthenware. I threw away the box that the clay came in, so I can't check, and now I'm concerned that the clay was stoneware and my pots should've been fired at a much higher temperature, like cone 5. The pots make the typical "tink" noise when I flick them with my fingernail, if that means anything. And they seem hard like they should be. Is there a way to tell if my pots have been fired to the proper temperature? If the clay was stoneware, would the pots still be fragile? I also have several bags of clay that were given to me. They are probably cone 06 earthenware clays, but I don't know; I'm just guessing. The person sometimes used stoneware clay, I recall. Is there a way to check these bags of clay to determine if they are earthenware? Do I make a tiny pinch pot and tap on it kinda hard? What would you do with unknown clay? Thanks for any responses.
  15. Whoa, thanks for anticipating my questions before I asked them, Arnold! I was going to make a post about witness cones. By the way, THE CALIBRATED KILN FIRED PERFECTLY! Well, maybe it fired a little too hot, as the tip dropped lower than the top of the base, but that's better than not hot enough! And it did not bend all the way to the bottom. Incidentally, this was the best YouTube video I found on the subject of calibrating the kiln sitter with a gage: http://www.youtu.be/...feature=mh_lolz Happiness is a properly bent witness cone.
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