Jump to content

Bill Kielb

Members
  • Content Count

    240
  • Joined

  • Last visited

Everything posted by Bill Kielb

  1. Looks like the default cone 6 value in the cone table is 2199. If you are checking thermocouples when you remove them snap a picture of the first inch or two and post. I will look through the manual tonight and see if anything stands out.
  2. This is not uncommon and on FAST GlAZE which is less accurate. Some things that affect this the kiln was loaded with lots of wares the shelving was spaced so as to restrict the radiant energy, ( not offset) The kiln exhaust pulls more air or through the course of the entire firing the shelves are a tad large for the kiln with only 1” or less spacing between the wall and shelf. many shelves installed for low flat wares the elements have a considerable number of firings on them kiln voltage calibration is not current kiln calibration has not been done for cone value offsets automatic controllers are great but not infallible. The difference between cone 6 and cone 7 is 30 degrees if fired at 108 degrees per hour in approximately the last 250 degrees of firing. Quetiinsmto be answered how long did you Fire? how many firings on the elements? how well packed was the kiln? single zone or multi zone control ?
  3. Bill Kielb

    Hardening of glaze

    Wonderful Artisty, I love it! Thanks!
  4. Bill Kielb

    Hardening of glaze

    Nice work! I’ll see if I can conjure up a very dry flat lithium matte tomorrow in the studio. One With better theoretical chemistry. No guarantees but it would be something you could then experiment with and hopefully be easier to maintain. The only different additional ingredient I can think of that I might use is a small amount of wollastonite. again,, very striking work! give me a couple days to mix and fire so at least I can send the recipe and some close up pictures don't worry about the addition to 95, I see many recipes that add up to less or more as folks have done the math by hand over the years.
  5. Appreciate the kind words but the community helped with a variety of well meaning opinions and you crawled in and did the work, so hats off to you. Sometimes ya just gotta take the credit. go first successful bisque firing!
  6. Bill Kielb

    Hardening of glaze

    My last attempt at this and just my opinion. Add bentonite (up to 2%) for recipes without sufficient clay to keep your glaze suspended. Limit your boron to about .5 no more even for cone 04 stuff. And finally she has a high percentage of Gerstley already so I am not sure where we are going with this. I mentioned bentonite because some of the previous posts speculated the recipe was not suspended. Mentioning Gerstley as a suspender in my view is not all that productive. just my opinion though so it’s worth the cost charged.
  7. Bill Kielb

    Hardening of glaze

    @neilestrick understood my point was in reference to bentonite really being a suspender not Gerstley
  8. Bill Kielb

    Ceramic Table Legs

    All the ideas seem great, I just don’t understand the look and quality you re seeking. Covers for the legs could be cast and glazed in sections, half section full hollow with any shape interior you would like. The covers could be slid over from the bottom up, retaining is easy enough to work out as filler (foam) and mechanical can be easily created. Concrete is not a great choice for wood infill since it’s expantion and contraction will not be the same as the wood and it’s tensile strength is poor without reinforcement so under support and reveals could be used. Concrete can be polished, stained, you name it. I guess it’s hard to suggest workable methods without knowing what the overall look and flavor of this is going to be.
  9. Bill Kielb

    Hardening of glaze

    My advice, unless this gives spectacular results just mix up a proper lithium matte for cone 04. It likely will save natural resources and perform consistently. Certainly can be durable as well so unless this is extra special I would replace it. The 100 gram issue is minor and I have posted the normalized one to the 100 th gram already so just use the 100% batch column on the spreadsheet if that is the issue.
  10. Bill Kielb

    Hardening of glaze

    @Mark C. molten earth?
  11. Bill Kielb

    Hardening of glaze

    @neilestrick Apparently at almost 37% Gerstley, that is not working right now. See analysis above, this glaze has lots of issues. Gerstley is not a great suspender, bentonite much more traditional up to 2% maximum
  12. Alright we have waited long enough, time to brag about your first firing.
  13. Bill Kielb

    Hardening of glaze

    Two percent is generally the maximum
  14. Bill Kielb

    Hardening of glaze

    Alright, here is my opinion and the whys Normalizing this to 100% really does not change much (See 100% batch column) This glaze lacks 10% or more clay so it is unlikely to stay suspended (5.26% EPK) Boron levels at .45 make this an 04 glaze. Not sure if that is what it is supposed to be or did someone add Gerstley until they sort of melted the giant amount of silica (Sort of) The chemistry in Stull is poor and shows underfired (Not good) The high R20 indicates it is not durable. (Very high early melt) 44% silica is extremely high .11 Effective Alumina is low (Very low) Lithium Carb is water soluble which adds more difficulty to the whole thing The basic chemistry says: Not durable, hard to tell where it fires, artistic only and likely difficult to keep in suspension. If the desired surface and firing temperature is known I would just mix up a durable formulation to the look I wanted instead of this unless this yields some fantastic unreproducible result. Its hard for me to find anything redeeming about this recipe. Just my opinion and basis for though.
  15. Bill Kielb

    Glaze Chemisty Education

    @tinbucket Here is a link to a very basic video we are starting to do for newbies in the studio. Intentionally Very simple to try and get folks thinking in terms of overall chemistry of the glaze without a bunch of chemistry actually. If you like it add it to your list of resources.
  16. Bill Kielb

    Time for a New Thermocouple?

    Definitely a loose connection or intermittent open in the wiring. I would check all Connections both ends as soon as practical and locate the intermittent connection. running it with an intermittent fault and hoping seems risky to me.
  17. Bill Kielb

    Bubbles in Glaze

    I just take my old pinstripe tape, tape a uniform line. glaze the inside and Rim dip to the line. When able, remove tape and dip outside glaze to the line. Nice and smooth transition, done!
  18. Bill Kielb

    Bubbles in Glaze

    Many of these lowfire crystalline glazes are decorative only. Often growing crystals or floating things up in glaze does not yield a low COE glaze so forget about using them on porcelain. It is interesting to go to their website and see the variation they can obtain with less than durable formulas. Starbursts, crystals, flowing movement, and big color at low firing temps, you name it. The sample I posted is an old Bristol glaze that I was asked to rework for decoration. We will redesign it with a durable flux ratio but the way it works is to make the glaze actually runny (over fired) for the cone being fired and make it be a matte. True mattes are matte because they grow crystals so an over fired runny matte deposits the crystals at the bottom of the run. Titanium (light rutile) is the only colorant so bingo, blue and lavender hues. not very hard to do actually and I have labeled it as decorative only even after I remove the crazing. It should be a matte but runs so it’s overfired. Why would I ever assume it is durable.
  19. Bill Kielb

    Bubbles in Glaze

    I attached the warning they have in their website which says no food storage or beverage storage. In adddition they acknowledge that their glazes often craze which is definitely not good especially for lowfire products that absorb considerable amount of liquids because they don’t fully vitrify. So most would consider a glaze that crazes not suitable for food service. Personally I would not use this for food service, storage or consumption especially over a low fired absorbant clay body.
  20. Bill Kielb

    Bubbles in Glaze

    Simple boring video, but nice work with the liner glaze!
  21. Bill Kielb

    Bubbles in Glaze

    Nice spot for the controller! I love the handwriting on the original nameplate. 3000 W test kiln, pretty neat stuff. I like old stuff though. Hopefully you have some ventilation in the area or this is outdoors.
  22. Bill Kielb

    Bubbles in Glaze

    @Narelle Got to thinking about your glaze as these are specialized lowfire things that don’t have the best reputation for liner use. They tend to craze and some are marked specifically not for food use as I recall. I am not a lowfire clay guy as the body never can be vitrified. Someone might have some and be able to read what is on the bottle. These glazes are designed to mature fully at 04, A bit hotter than 06. Check your label on the bottle. SAFETY DATA Ceramic ware that has been coated with Fantasy Glazes should not be used for the storage of food and beverages. The Fantasy Glazes in all cases are lead free. Several may contain encapsulated cadmium or copper compounds and due to the nature of these types of glazes, they will have a tendency to craze. Always refer to the bottle for all hazards and safety instructions.
  23. Bill Kielb

    Bubbles in Glaze

    @Narelle just a note about crazing. Crazing happens when the glaze shrinks faster than the clay. We call this a glaze fit issue so generally if a glaze crazes on a particular body it is not a close enough fit and will likely always craze on that body unless adjusted chemically to be a closer fit. Crazing can occur right away or hours, days, months later. In general if the glaze does not fit well enough it likely will eventually craze regardless of the firing speed and cooling speed. a glaze with a marginal fit to the body will also exhibit crazing when the glaze is thicker. Often we see the development in the bottoms of pots where glaze has been artistically applied and intentionally runs down into the center for effect I have pictures below showing a glaze we are developing for someone at the studio. The glaze was made as a matte and intentionally over melted to get the crystal effect at the bottom of the runs. The bowl is crazed (hard to see in the picture) where thickest, the sample tile is not. 2 grams of whiting was removed from the recipe to get the fit between body and glaze closer to a match on the sample tile. So far no crazing in the sample tile. I mention this because I believe you are using commercial 06 glazes for which there is no published recipe, so this glaze may end up being unsuitable for your claybody regardless of what you do, unless of course you desire the crazed look. Or perhaps it has crazed where applied thick. Generally for mugs, this is not considered a durable finish though. slower heating likely will not solve this problem. Finally for our studio we have been doing some basic YouTube videos for those new to clay. Our latest is a basic introduction to glaze, you may find it useful
  24. Bill Kielb

    Holidays and Themes

    They are about three to four inches long, cone six porcelain fired to six, hand carved, hand underglazed, signed by the artist on the back with a date (year) and glazed all sides using one of two tested durable glaze clear recipes . (Matte and gloss) sprayed by me. Nice even coats all around, no drips, same thickness. then they are affixed to various presents as a new Christmas keepsake. what are they worth? I’ll let you answer that. thanks BTW I appreciate the compliment.
×

Important Information

By using this site, you agree to our Terms of Use.