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Tina01

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  1. Like
    Tina01 got a reaction from rdroza in Why my clay acts like this?   
    Hi all! 
    Some updates... I finally built and cooked my first pot! : ) well... it's a vase I guess. I don't know if it has cooked thoroughly or not, but it turn from slightly greenish gray to pinkish beige. A few small areas had a different , more saturated green hue when I took it out of my kiln. It's hard on surface, not scratches with fingernails but does with sharp metals. Absorbs water but doesn’t disolve or making my finger muddy when rubbing it wet. Still I'm afraid to fill it with water although some smaller thinner testing items I cooked with it are still  holding strong  under water after 20 days.

    hunting/making clay is still in progress. as the last formula didn't work (infact it couldn't be tested as it had a horrible smell, something like fetid swamp rotten eggs after 5 days). Most likely because my bentonite keeps molding, no matter how many times I remove the mold layer from the top. So I finally mixed all the different clays I had and still working on dry powders to find a solution. 
  2. Like
    Tina01 reacted to PeterH in Why my clay acts like this?   
    You could prevent the mould by adding a biocide. Short lived ones (that require topping up) are hydrogen peroxide and bleach (but bleach may be hard on the hands). A long-lived one is copper carbonate. 
    The Best Way to Eliminate Odor from a Stinky Ceramic Slop or Glaze Bucket
    - Try to make sure that your waste doesn't get near any aquatic life, especially if you use a long-lived biocide.
    - I could understand your "wild" clay going mouldy if it has lots of organics in it, but am surprised that shop-bought bentonite does.
  3. Like
    Tina01 got a reaction from Kelly in AK in Why my clay acts like this?   
    : ) Thank you sooooo much! kisses! ; )
  4. Like
    Tina01 reacted to Kelly in AK in Why my clay acts like this?   
    Tina! You just made my day.
  5. Like
    Tina01 got a reaction from Callie Beller Diesel in Why my clay acts like this?   
    Hi all! 
    Some updates... I finally built and cooked my first pot! : ) well... it's a vase I guess. I don't know if it has cooked thoroughly or not, but it turn from slightly greenish gray to pinkish beige. A few small areas had a different , more saturated green hue when I took it out of my kiln. It's hard on surface, not scratches with fingernails but does with sharp metals. Absorbs water but doesn’t disolve or making my finger muddy when rubbing it wet. Still I'm afraid to fill it with water although some smaller thinner testing items I cooked with it are still  holding strong  under water after 20 days.

    hunting/making clay is still in progress. as the last formula didn't work (infact it couldn't be tested as it had a horrible smell, something like fetid swamp rotten eggs after 5 days). Most likely because my bentonite keeps molding, no matter how many times I remove the mold layer from the top. So I finally mixed all the different clays I had and still working on dry powders to find a solution. 
  6. Like
    Tina01 got a reaction from Hulk in Why my clay acts like this?   
    Hi all! 
    Some updates... I finally built and cooked my first pot! : ) well... it's a vase I guess. I don't know if it has cooked thoroughly or not, but it turn from slightly greenish gray to pinkish beige. A few small areas had a different , more saturated green hue when I took it out of my kiln. It's hard on surface, not scratches with fingernails but does with sharp metals. Absorbs water but doesn’t disolve or making my finger muddy when rubbing it wet. Still I'm afraid to fill it with water although some smaller thinner testing items I cooked with it are still  holding strong  under water after 20 days.

    hunting/making clay is still in progress. as the last formula didn't work (infact it couldn't be tested as it had a horrible smell, something like fetid swamp rotten eggs after 5 days). Most likely because my bentonite keeps molding, no matter how many times I remove the mold layer from the top. So I finally mixed all the different clays I had and still working on dry powders to find a solution. 
  7. Like
    Tina01 reacted to PeterH in Why my clay acts like this?   
    What is (probably) important is that you add the bentonite in very small quantities, preferably sprinkled over a significant area. Then allow a little time before agitation, as you really want the bentonite to drop through the surface into the water of its own accord.
    IIRC the way it would be done in a lab is to place all the bentonite in a thin line on a glazed tile. Then cut small lengths off the line as required with a sharp edge (traditionally a razor blade).
  8. Like
    Tina01 reacted to Babs in Why my clay acts like this?   
    I'd dip that in water then put in plastic for a while.
  9. Like
    Tina01 reacted to Babs in Why my clay acts like this?   
    Typo back a bit
    AmphoTERIC is what you need.
    What is Tina's source of water?
    Could be  alkaline already?
  10. Like
    Tina01 reacted to glazenerd in Why my clay acts like this?   
    Final before I go to work (suppose be retired- yeah right!  Once I figure out a measuring system for you; I am also going to do a PH test. I use a PH meter to mix certain glazes, and to check alkalinity levels of certain clay blends. The short term fix will to be add a specified amount of baking soda to your water; stir and dissolve it: then pour off the water- leaving the residue behind. That alkaline water will then become what you mix your clay with. I will PH check it to make sure it is not too high. There only needs to be a minimum amount of PH to break the effects of acidity; do not need much.
    Tom
  11. Like
    Tina01 reacted to glazenerd in Why my clay acts like this?   
    Tina:
    I used baking soda for an experiment because you did not have access to feldspars. Clay reacts to two extremes: acidity creates strong flocculation; but equally strong alkalinity (above 9.8 PH) also creates very strong flocculation. The PH of baking soda would be classified as "caustic" in the clay chemistry world. For that reason, I asked you to google search potassium fertilizer; trying to figure out an alternate source that is readily available to you.
    Tom
  12. Like
    Tina01 reacted to glazenerd in Why my clay acts like this?   
    Tina:
    One final experiment: take a golf/ ping pong ball size piece of your brown clay. Add just a few drops of water and wedge it it; needs a little more moisture. Then put a "pinch" of baking soda on it; wedge that in. Then add a second pinch of baking soda; then wedge that in. Let it sit about an hour. and do the coil test- wrap it around you finger. That will tell me how much acidity/ and or positive charges (iron and alumina) is effecting plasticity. Once I know that; this weekend I will measure out and weigh a clay I believe similar to yours. Then weigh out how much bentonite. I will post a ratio: x amount of bentonite for every cup of clay. You can then mix by multiplying that base recipe. Unless you have a scale; then life gets easier.
    Tom
  13. Like
    Tina01 reacted to glazenerd in Why my clay acts like this?   
    The term is "amphoretic."  Certain acids (vinegar/lemon juice) when mixed with other acids create a specific reaction that creates alkalinity. One of those "freaks" of chemistry. The Amish use a mix of vinegar and herbs to treat acid indigestion for that reason. The other thing missing in this equation is: commercial clay bodies have 10-35% feldspar content: your body has 0-1%- so the intended reaction will not occur.  I will resist my urge to go on a long rant about monovalent sodium ions.
    Tom
  14. Like
    Tina01 reacted to Babs in Why my clay acts like this?   
    Then it may well help Tina. Test and see
  15. Like
    Tina01 reacted to PeterH in Why my clay acts like this?   
    Tony Hansen https://digitalfire.com/material/vinegar
  16. Like
    Tina01 reacted to Babs in Why my clay acts like this?   
    I think a pinch of Bentonite, your clay is almost there.
    Like some foods; a little tastes  delicious, too much will kill you.
    I only mentioned vinegar because some very  experienced potter  mentioned it and I do use it  in my throwing water, makes it creamy. I also use it when attaching handles , or slabs. The chemistry I leave to someone else.
    This is a caring community  Tina, seen by the continued thought  being given to trying to solve your problem.
     
  17. Like
    Tina01 reacted to Callie Beller Diesel in Why my clay acts like this?   
    Don’t be disheartened by your result when you added too much bentonite. It’s not uncommon for some of a material to be good, but too much will “break” it. Usually when you add bentonite to a clay body, it’s only in quantities of 2-3% by weight. It’s a very powerful plasticizer, absorbs water rapidly and doesn’t like to let it go. It’s used in clumping cat litter for that reason.
  18. Like
    Tina01 reacted to Tina01 in Why my clay acts like this?   
    @glazenerd adding bentonite was totally wrong. I added 1 teaspoon to 250g of clay. 
    https://sendvid.com/hb3db3wr
    wet but crumbling, couldn't even wedge. wasn't clay anymore. 
  19. Like
    Tina01 reacted to Kelly in AK in Why my clay acts like this?   
    I respect that sentiment. What is available to you may very well dictate what you make. That is the order of history. In my city there is one other person using the local clay in significant quantities. He makes tiles and that’s all. That’s because it’s the only thing he sees the clay is good for. He is no fool, all my life no one has said the clay here is good for anything. I make pots with it that are functional by any standard, but it has taken a few years to achieve. You will not solve this in days or weeks. You will solve it if it is your path. 
    Alaska has no ceramic tradition. Georgia does. Avail yourself of it. Our cultures are different, I understand that may be easier said than done. 
    I also appreciate your attitude toward fixing the clay issues before considering glazing. You must, however, fire any clay you are messing with. You MUST. It is inextricably linked to producing pottery. A small piece placed inside a container in a kiln poses no risk to anyone else’s work, but will give you a great deal of information. There is no sense in finding clay you can form well but turns into bubbling froth, or remains as weak as greenware, when fired.
    Your determination and attention to detail are impressive. I hope you solve this, I hope to see pictures of your pottery someday.
    Pioneer Pottery by Michael Cardew is an invaluable resource. There are sections on clay that would be useful for you now. Other parts of the book will be helpful later. Whether you’re buying clay or digging it up, you can at least be more informed on the basics. It is freely available on archive .org if you can access that. 
  20. Like
    Tina01 got a reaction from Kelly in AK in Why my clay acts like this?   
    No.... I don't want you or anyone else to be in trouble for me, that was a favor thanks, but no need to contact others for me.
    Ok now that it's sodium bentonite, it isn't Fullers Earth? should I mix it with clay or not? if so, in how much percent? (either by volume or weight). the volume is easier. 
  21. Like
    Tina01 reacted to PeterH in Why my clay acts like this?   
    Fuller's Earth https://en.wikipedia.org/wiki/Fuller's_earth
    Fuller's earth is any clay material that has the capability to decolorize oil or other liquids without the use of harsh chemical treatment.[1][2] Fuller's earth typically consists of palygorskite (attapulgite) or bentonite.[1]
    Modern uses of fuller's earth include as absorbents for oil, grease, and animal waste (cat litter) and as a carrier for pesticides and fertilizers. Minor uses include filtering, clarifying, and decolorizing; active and inactive ingredient in beauty products; and as a filler in paint, plaster, adhesives, and pharmaceuticals.[1] It also has a number of uses in the film industry and on stage.
    Probably bad news, cat litter may often be calcium bentonite. 
    See Digitalfire for the difference https://digitalfire.com/material/bentonite
  22. Like
    Tina01 reacted to glazenerd in Why my clay acts like this?   
    Tina:
    When deciding what to add or remove in a clay body; it comes down to application and firing technique. 1. Functional or non-functional. Functional has specific limits, non-functional has none. 2. Firing- pit, kiln, raku: different firing techniques create their own demands on clay. So before I can answer: how do you plan on firing it? What temperature (cone) do you plan on firing it to? Are you making functional or non-functional pieces.
    Tom
     
  23. Like
    Tina01 reacted to Babs in Why my clay acts like this?   
    Btw if you are sieving and washing, you msy be throwing away the fine particles you require for plasticity
  24. Like
    Tina01 reacted to Babs in Why my clay acts like this?   
    That cracking at edges when rolling shortish, i.e. low plasticity clay body, is common.
    Releasing clay between rolls, rolling in different directions,
    rolling in a gentle manner can alleviate this.
    From your wedged slab, cut a slice close to the thickness you require, the less handling the better imo. i.e. less stretched
    Clay may need to be  a little wetter.
    Try rolling on a canvas.
    Just thoughts.
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