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About BlackandWhitedogpottery

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  1. Does anyone have a good ^8-^9 clear glaze recipe?
  2. So. I was doing some deep research for a incredibly strong clay body and I came across this pretty vague recipe, I was wondering if anyone could help me decode this (what a challenge ) Stone Body Stone 200 parts Cornwall Clay 150 parts Blue Clay 200 parts Flint 100 parts Calx 1 parts There was no firing temperature but "fire hard" What is Calx, Blue Clay, Stone, and another strange clay I saw. Cawk Clay Any input will be greatly appreciated
  3. Looking for some help with regarding stains .. When using stains in maybe 10% increments has anyone noticed it affecting the melt of the glaze? I have a runny glaze that I like that will run always but when I add 10% tin (i like it white) it stops running down onto the kiln but it runs onto itself. Do stains work in the same way in the way of stiffening?
  4. I ended up trying it.... So this is what went down, It lacked any kind of binding at all, I mean it felt like it made it even more flakier. It ended up cracking apart and falling off in chunks that would instantly turn into powder when they hit the table. Also applying it was a nightmare, instant dry out when applied to the pot. I felt bad for wasting the tin oxide in the test :/
  5. Does anyone have any suggestions for making glazes in warm grey or beige in cone 6?
  6. I was wondering has anyone tried this before. I found online someone was making kiln shelves from zircopax and zeegum, rolling slabs and making shelves. I'm having a hard time finding plate setters because I need about 30 for 6" saucers fired at ^6. I thought about maybe using clay but from experience clay becomes super brittle and cracks after firing a few times Thank you
  7. I did run a quick test of adding RIO to slip just out of curiosity at my last firing. It looked like minute specks of pepper that came up in the clear glaze and hardly showed in the tin glaze. So. I have granular rutile on order right now. Any recommendations on how much to add for light speckling? I did add 2% of the soft bisque grog to wet clay last time and it was pretty speckled from what I could tell. I have found percentages for glaze but not much for clay. Lastly..I have searched but haven't found anything that flat out says it but are there any real issues with granular rutile? (toxicity..) Thank you
  8. I've didnt know of the reduction technique, I thought that was a only for porcelain and copper reds. I was just thinking an iron "grog" would work similar like pieces of trash iron that show up in stoneware clays with white glazes I will look into granular ilmenite. Would it make light light orange?
  9. Hello everyone. I have a goal I would like to accomplish but I would like to run these ideas by first. My 1st goal is to have a smooth clay body with faint to light orange round speckles, my 2nd is to have long brown bleeds going down the side of the pot. I have been using speckled buff from my clay supplier but I would like to try my own. I have a white glaze I intend on using for this so I'm mainly working on additives to a smooth buff clay body I buy that I fire to cone 6 My Idea was adding percentages of iron oxide to the buff clay, ranging from 1%-5% to 15%-25%, mixing it with dry ground clay and then mixing as a slip then firing to cone 6. Taking this then grinding/sifting through fine mesh. Mixing in percentages to wet clay and going from there. Has anyone had any similar experiences? I would like to avoid Manganese since I'm a little leary about it, and I have thought about iron shillings but I was looking for something a bit more backed by "set in stone" recipes and additives to clay Thank you
  10. Does anyone have an idea on how to make a glaze like this color in cone 6?
  11. I believe the "5%" refers to the amount of copper one can put in a glaze before it starts leeching -- which would make the glaze non-food safe. Same for cobalt. The 5% level was the rule of thumb used by John Hesselberth and Ron Roy in Mastering Cone 6 Glazes. They generally tried to keep copper below that percentage to ensure the glaze was durable, stabile, and food-safe. Hesselberth and Roy followed standards for testing for water purity -- there are not similar standards for pottery glazes. The percentage of red iron oxide -- 9% -- is not excessive; I've seen recipes going up to 18% for some iron reds. Also, red iron oxide is not toxic. Zinc oxide is used as a flux; it often enhances color response, especially in copper and cobalt glazes. Zinc oxide is a toxic hazard -- it can have lead impurities. You can check the MSDS for the zinc oxide you buy to see what the chemical analysis is -- likely any lead is below acceptable levels established by the government. And, whether you buy on-line or from a pottery supply store, they are required to have copies of the MSDS for each item sold and to make those available to consumers. If they don't have them -- or refuse to let you see them -- find another supplier. You can play it safe by having a professional laboratory test for either zinc or lead leaching. Or, you can take the easy route and use a safe liner glaze for insides of vessels. This is what I found from Digitalfire "Another simple thing you can check for is material amounts that do not seem normal. It is common, for example, to see 5% talc in a glaze, but 30% is definitely not normal. Likewise more than 5% lithium carbonate or zinc is strange and needs explaining." but then I found this too from Digitalfire... "Superpax, Zircopax, Opax, Ultrox, etc are zircon or zirconium silicates, they are inert and should not be a problem Iron and zinc oxide are not harmful."
  12. Do you think this glaze has enough silica and alumina to seal off the cobalt? I was just wondering before I started making test batches.
  13. So for French process is used in cosmetics? So then it is food safe. Is there a way to tell the difference in an American processed Zinc and a French processed Zinc? Or would it just be impossible to buy American Zinc from a pottery supply since it contains lead? I looked on my suppliers website and couldnt find any details about the Zinc
  14. I have looking through various glazes for ^6 glazes and noticed that quite a few contain Zinc Oxide. The more research I did on Zinc the more I became concerned with the food safe issues and a little confused about the lead issues. In one place I read that if a glaze contained anymore than 5% if was questionable and 10% down right strange, but then there's glazes I've come up that require up to 7% - 12% For example. (oxidation) Glossy Black ^6 42% Feldspar 26% Silica 15% Whiting 12% Zinc Oxide 9% Red Iron Oxide 2% Cobalt Is this glaze food safe at all for the amount of Zinc and the amount of Iron Oxide? Like for the inside of bowls and cups? Thanks
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