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neilestrick

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Everything posted by neilestrick

  1. Grog will bump up the peak temp. Is it a coarse grog or fine? I could see 266 being really nice with fine grog. Also, is the grog visible in the fired clay?
  2. 50F/hr is really slow for a cooling cycle. You'll see a difference with a lot of glazes at 150/hr cooling rate. I'd start with a faster cooling rate and slow it down from there.
  3. If they're going into a wood fired kiln, they'll get ash in the kiln. Why apply it before?
  4. If it has zone control, just distribute the load somewhat evenly, rather than having an empty section. If it doesn't have zone control, leave the bottom empty.
  5. You can make really nice copper reds in oxidation by using silicon carbide for localized reduction. You can also make all sorts of nice iron reds and oranges in oxidation, typically with the addition of bone ash. And yellows and oranges with rutile. You actually have a lot more options for color in cone 6 oxidation than you do in cone 10 reduction, because may colors are more stable at the lower temperature.
  6. Your photo isn't displaying on my computer. Is anyone seeing it? The holes should not affect the structural integrity of the bricks. If they're going to crack, they'll do it with or without the holes. But even if they do, if the compression system is good the cracks won't matter because the bricks can't move anyway. If the holes were an issue, filling them with fiber won't help. You would have to make little rods of brick and mortar them in place.
  7. If you're handy with basic woodworking tools, there are ways of making pedestals so they fold flat. Google it. It makes it a lot easier to transport them. Make them out of 3/8" thick plywood or MDF and they'll last forever.
  8. Elementary teachers tend to do cone 04 work because there has always been an abundance of premixed glazes available for low fire work. Those glazes are easy to use, and have more color options that younger kids like, like bright colors. Until recently, there weren't all that many good cone 6 glazes available. Elementary teachers can do cone 6 or even cone 10 work if they want to, as long as the materials are certified non-toxic and safe for kids to use. Cone 6 and 10 glazes can be certified non-toxic just like 04 glazes.
  9. Only in that we understand them better, and are more focused than before on making glazes that are durable and safe, rather than glazes that just look good and are easy to make.
  10. If I'm understanding the direction of the hole, it won't show when the bricks are used for a kiln wall, correct? I wouldn't even worry about the hole. At 5/8" it's likely not going to affect the insulating properties of the bricks enough to matter. If the hole will show and allow heat to escape, then fiber is probably the best way to go. Wear a respirator when using the fiber.
  11. It is virtually identical to Gerstley of a specific year. It was different every few years as they moved through the deposit. Which year they chose to use as their baseline I do not know. I've been using Gillespie for about 15 years, and it's always been stronger than Gerstley during that period, and I've had several customers says the same thing. Typically you'll need 3-4% less Gillespie than Gerstley.
  12. How fast you need to bisque depends entirely on your clay. The purpose is to harden the clay so it's less fragile for glazing, and to burn out all the organic materials. White stoneware and porcelain bodies can be bisque fired faster since they generally have less stuff to burn out. Brown clays and terra cotta need longer because they aren't as pure. Bisque firing should take anywhere from 5-6 hours to over 12 hours. Most people bisque in the 8-12 hour range.
  13. Even a 6 cu/ft kiln should get up to cone 018 in just a few hours. The problem is that a kiln that size will take longer to cool than a smaller kiln. Did that 20 hours include the cooling segment? Putting that segment in the program isn't necessary. If it's cooling at 9999, that's full speed, cooling at its natural speed. Just take it up to peak temp and let it shut off. Speed up your firing speed. 110F/hr is pretty slow. You can go as fast as your pots will allow without cracking. You also don't need to wait for it to get all the way down to 80F. Open it up at 200. That last 120 degrees could take several hours.
  14. If you've already fired the piece to 1280, it's likely already vitrified, and you'll have a really hard tome getting anything to stick to it. Typically we bisque to cone 06-04 so the piece is still porous for applying the glaze.
  15. The Skutt 181 needs a 30 amp breaker. A 50 amp breaker would not be within code, which says the breaker should be 25% greater than the draw of the kiln, but not more than 50% greater. If I remember correctly the 181 only pulls 22-24 amps, so at 150% a 40 amp breaker would be the largest. The KM818 pulls 27.8 amps, so at 25% greater you'd need a 40 amp breaker. At 50% greater, that gets you to 42 amps, which technically allows for the use of a 50 amp breaker, but I'd stick with the 40 for that, too.
  16. 90 minutes is too fast! You're lucky you didn't blow things up. Does it have a switch that can control the power (lo, med, hi)?
  17. L&L only recommends putting holes in the lid if needed. Try it without first. You can always add them.
  18. If it works as it should with the 4 small belts, I would just stay with that system. Just keep your belts in good working order and you won't have any problems. When you say 'wait for someone to get an order in to Laguna', what do you mean? You can call them directly to order, or you can get them through a number of other clay suppliers like Sheffield, Clay Planet, etc.
  19. If you want an accurate test, then you should wait until it's as cool as you would normally open the kiln. 150 is lower than you really need to go IMO. 200-250F is safe. I open at 300F without any ill effects.
  20. Have you talked with any of the manufacturers to see if they have a method of expanding the nozzle? If you can't find a studio model that is big enough, you'd have to go to an industrial machine, which is a really big jump up in size and cost.
  21. Will the pug be a solid pug, or will you be using a die on the end? If you're using a die to extrude a particular shape, it's possible for the extrusion die width to be greater than the nozzle width, because the clay will squish out to fill the die.
  22. @Nir Dvash Clay can stick to clay even if it's not glazed. If you were firing those to full maturity they would totally stick together.
  23. Thin porcelain pieces can be ripped apart by the glaze when only one side is glazed. Are you using alumina wax on the supporting ring to keep it from sticking to the plate? If not, it could be that they're binding up and causing the cracking.
  24. Standard 365 cone 6 grolleg porcelain throws really well, and is white and translucent. I've used it for years. I've even used it for 4 piece, 50 pound planters with no cracks or warping. If there's a Standard distributor out there, give it a try.
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