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Dick White

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  1. I have found with hump molds that often the very edge of the slab needs to be gently picked loose from the edge of the mold/form so that the slab is not hooked over the edge and can slide upward slightly as the overall slab shrinks while drying. Usually the rest of the slab will release easily when it has dried slightly, but don't take it off until it is dry and strong enough to hold its shape on its own.
  2. Pyrometer Usage?

    I agree with the recommendation for a protection tube. First, as noted, it will protect the thermocouple both from striking it with a shelf and from the corrosive fumes so it will last longer. But it is protection in the other direction too. The exposed tip will corrode and a rusty powder will begin to flake off, landing on and contaminating any glazeware underneath it. Before I installed protection tubes, I had to leave that segment of each shelf empty. However, there is another thing to keep in mind with protection tubes. They do have a slight insulating value, so the thermocouple will read cooler than the actual kiln temperature. This will also introduce lag, meaning that during a heating or cooling ramp the temperature change sensed by the thermocouple is running behind the actual performance. Electronic kiln controls typically have offsets and adjustments that can be programmed, but with a handheld pyrometer, you are the computer.
  3. Prediction required

    Looking at it in Glazemaster, it should be ok, though different as Mark correctly predicts... The alkali level is higher (.26 now vs. .22), but not out of range. However, now the alkali content is dominated by sodium from the frit vs. lithium from the spod, and this changes the expansion quite a bit so there might be a glaze fit problem. The Si:Al ratio is lower (6.5 now vs 7.2) because of the added clay, but not completely out of range. The big change is in the boron - now .28 vs. .07. That will add some melting and gloss. Let us know how it looks when it comes out of the kiln.
  4. L&L Kiln - E22 & 26 Error Codes

    Get the refurb Genesis. You're paying half what I paid for mine directly from Barlett. I wonder if they will sell me a refurb, I have 2 other kilns that could use an upgrade at half price...
  5. Relay Life Update

    Thank you Neil for stepping up.
  6. Too short to throw standing up

    First, decide if you are more comfortable throwing while sitting (in the adjustable chair) or standing (on some sort of platform). When you have settled on a comfortable position to work, attach a block of wood to the footpad of the pedal to raise it to the appropriate height for wherever your foot happens to be.
  7. The E-1 code means the kiln is not able to generate enough heat to raise the temperature any higher. Typically this will happen when either all the elements are getting old and can't generate enough heat anymore, or one element is broken and the other good elements can't generate enough heat to compensate for the broken one. It takes less energy to raise the temperature at lower temperatures, so the E-1 error usually does not appear until later in the firing. It is possible that a shard from the bisque explosion remained lodged in the element coil despite your careful vacuuming, and that might have caused the element to overheat at that spot and break? Empty the kiln when it is cool and carefully inspect the elements for any breaks. A quick test to find a nonfunctioning element is slip a small piece of paper behind each element coil and turn the kiln on to a fast cone anything. Let it run for a few minutes and then shut it off. The slips of paper behind each element should begin to char as the element turned on. If any of the papers are not charred, that element is not functioning.
  8. Crystalline Glaze Chemstry

    OMG, ASDF, or whatever initials the kids use these days to say that's awesome! Have you tested the body with other glaze formulations, e.g., different frit combinations, additions of alkaline earth fluxes, and, just as important, variations of colorant?
  9. Frit 3110 issue

    Are you sure it is 3110, as others have said? If you got it from a crystallier, could it be Fusion 644, which despite its other benefits, has the sad behavior of solidifying in the bag. (I break chunks out with a hammer and chisel, and then grind it in a coffee mill before I can use it.)
  10. Glazes That Break

    Actually, the opposite. Illmenite is a raw source that is refined into rutile, which in turn is further refined into titanium. The illmenite is roughly 50:50 iron and titanium oxides; rutile is roughly 10:90 iron and titanium.
  11. Zinc in glazes

    First, can you identify the strong acids in your glaze recipe? If not, then the problem of zinc solubility in the presence of strong acids isn't a problem. I don't know about your glazes, but mine tend not to have strong acidic properties. The bigger problem with zinc glazes is the unattractive way it interacts with chrome as a colorant. If you are in total control of the oxide colorants in your glazes, just keep chrome away from a zinc-bearing glaze. If you use stains, either in the glaze or in an underlying slip, you need to learn what oxides were used by the manufacturer to achieve that color. Mason publishes a reference guide, but other sources are a mystery. As for replacing zinc, that is a challenge. Zinc performs as one of the RO fluxes. But it also imparts other qualities to the glaze (opacity, surface durability) which are not easily replicated by swapping with other fluxes.
  12. Table top fountain design

    I agree with Neil, don't have any openings in the main vessel that will be below the water level in the reservoir. It will leak when you least expect it, and in the worst possible location. As part of the overall design, develop some sculptural elements around the edge of the vessel that can hide the cord. The particular element that will house the cord must be designed so that the cord tucks under it somehow, out of sight but still removable. The small pump will need to be removed periodically to clean the gunk that will inevitable clog the filter inlet.
  13. Genesis Controller

    I really like my Genesis. I bought it direct from Bartlett and built my own external wall-hung controller with it. The additional features and ease of use over the earlier V6-CF are worth the extra cost. The only thing I don't like about it is that Bartlett doesn't seem to have any idea how the customer side of a software company operates, in that they don't offer any information about the changes that are in each firmware update. The version number of the user document on their website can only be determined by the download filename, not printed on the cover page, and is an older version than was most recently installed, and thus I have no clue what new features are being installed in my controller when it updates itself other than a page-by-page line-by-line comparison of this document vs. the last one I happened to have collected. Neil, what can you tell us about the availability of this new mobile app?
  14. Why Calcine China Clay?

    China Clay and Kaolin are generic names that are often used interchangably. There are some specific technical/chemical differences between brands of kaolin, e.g., EPK, Tile6, Grollegg, but unless you are working with a highly nuanced recipe or situation, it probably won't matter which brand of kaolin/china clay was calcined and put in that bag.
  15. Updating kilns

    The power side of it is easy, though expensive, with an appropriately rated transfer switch. We have 2 of them in the community center studio where I teach. Handle up, 60A kiln plug on the left has power; handle down, 60A kiln plug on the right has power. We do that not for control purposes, but because there isn't enough power/circuits in the building to run both at the same time. A shared digital controller is going to be the issue. The thermocouple driving the controller must be in the kiln that is being powered by the controller. We can swap the power from one to the other with a switch (or manually unplug kiln A from the receptacle on the side of the wall controller and plug kiln B in), but swapping thermocouples from one kiln to the other (or installing a switch to change between 2 thermocouples in different kilns all the while ensuring that the thermocouple switch position matches the power direction) is a another kettle of fish.
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