Why my clay acts like this?

[glazenerd]

10 hours ago, Tina01 said:

couldn't run the test (see the pictures above). It was an immediate transform. 

and that is how you know it is sodium bentonite: it swelled, became gelatinous. Calcium bentonite does not have that same reaction.

Tom

[glazenerd]

Sent an email to a Russian potter, another in the Chech Republic: both collect and process wild clay. Trying to get a handle on what is available in your region.

Tom

[glazenerd]

Tina:

a heads up; I do not have a smart phone, and my Ipad is about dead. This means I can only respond at certain times.

Tom

[Tina01]

48 minutes ago, glazenerd said:

Sent an email to a Russian potter, another in the Chech Republic: both collect and process wild clay. Trying to get a handle on what is available in your region.

Tom

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. 

[Min]

14 hours ago, neilestrick said:

I'm not trying to be a downer, but I think your best bet is to contact another potter in the area and see where they get their clay. You could spend a ton of time trying to figure this out and end up not being able to fix it. Most clays are not used alone, but are blended with other clays to achieve the properties you need, and not all clays are good for making pots. The other thing you need to consider is your ability to fire pots. If you can only get to 900C (cone 010), then you're not going to be able to make functional work. Pit firing and other non-functional techniques can make some really great work, though. You really need to be able to get to 1000C in order to use glazes.

@Tina01, firing temperature is a really important point if you are wanting to make functional pots.  Have you tried your kiln to see how hot it will go or do you have access to a kiln that will fire hotter than 900C? It would be a shame to go to all this work of creating a useable clay only to find you can't fire it adequately for your intended use. May I also ask if you have glaze materials or commercial lowfire  glazes available to you? 

[Tina01]

1 hour ago, Min said:

Have you tried your kiln to see how hot it will go or do you have access to a kiln that will fire hotter than 900C?

Not yet, (I haven't build it yet because there was nothing to fire). I don't want to use a kiln that is shared (my pots may break and break others). from YT videos that temperature or a little above shouldn't be hard to reach.

1 hour ago, Min said:

May I also ask if you have glaze materials or commercial lowfire  glazes available to you? 

I've found some sources that I can buy either powdered or ready to use glazes, with some variety of colors, and the one that i like is F38 glaze that is transparent. 

I don't know if I could apply that and have a successful glazing I guess it's in same temperature range. but for now I'm looking to fix the clay, as glazing is another complicated story... and to see if my clay will really bake or I should completely change my path.

unfortunately I don't have many choices ( to say well I need that cone clay, those additives, tools, those glazes and all get delivered to my door).

Thank you for your care and help.

[Tina01]

@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. 

[Babs]

1teaspoon aporox 30gms : 250 gms 12%. Quite a bit, was it mixed with water first?

May need to rest it before wedging if you added the powder of bentonite.

[Tina01]

25 minutes ago, Babs said:

1teaspoon aporox 30gms : 250 gms 12%. Quite a bit, was it mixed with water first?

May need to rest it before wedging if you added the powder of bentonite.

No, I mixed both in dry form then with water. after stirring well pour it on that black fabric to draw excess water and sat overnight. this was the next day result, dry on surface but wet underneath. scrub that from fabric and that was the final result in the video.

Even some ordinary mud is more clay like than that.  couldn't even make a thick coil out of it as it was breaking apart. 

Edited November 8, 2022 by Tina01

[Kelly in AK]

12 hours ago, Tina01 said:

unfortunately I don't have many choices ( to say well I need that cone clay, those additives, tools, those glazes and all get delivered to my door).

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. 

[Babs]

5 hours ago, Tina01 said:

No, I mixed both in dry form then with water. after stirring well pour it on that black fabric to draw excess water and sat overnight. this was the next day result, dry on surface but wet underneath. scrub that from fabric and that was the final result in the video.

Even some ordinary mud is more clay like than that.  couldn't even make a thick coil out of it as it was breaking apart. 

Leave it to slake overnight , try adding a little vinegar, stir then put IN cloth to drain. Then wrap and leave. Wedge next day.  May be different. If this is the clay which you wrapped around your finger, plasticity should not take much bentonite to sort. 

Worth a try. 

Edited November 8, 2022 by Babs

[Tina01]

3 hours ago, Kelly in AK said:

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. 

This was the kindest reply I've ever got! Your heartwarming words are really valuable to me and makes me more willing and active. 

So thank you  to the moon and back! it seems I can't post emojies here but a huge hug and kiss! 

I will certainly check out that book. Again, thank you! @ } ; -

[Tina01]

2 hours ago, Babs said:

Leave it to slake overnight , try adding a little vinegar, stir then put IN cloth to drain. Then wrap and leave. Wedge next day.  May be different. If this is the clay which you wrapped around your finger, plasticity should not take much bentonite to sort. 

Worth a try. 

Yes it was the same clay.

Vinegar? I think the soil is acidic why adding more vinegar? to settle small particles? 

Well I'm now totally afraid to add even a pinch of bentonite again because it had exactly the reverse effect of what I wanted! perhaps I added too much but still it shouldn't change it so drastically and in opposite direction! 

but since you are experienced I'll try that either!

TYSM for guidance. 

[Callie Beller Diesel]

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.

[Babs]

10 hours ago, Tina01 said:

Yes it was the same clay.

Vinegar? I think the soil is acidic why adding more vinegar? to settle small particles? 

Well I'm now totally afraid to add even a pinch of bentonite again because it had exactly the reverse effect of what I wanted! perhaps I added too much but still it shouldn't change it so drastically and in opposite direction! 

but since you are experienced I'll try that either!

TYSM for guidance. 

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.

 

[PeterH]

35 minutes ago, Babs said:

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.

Tony Hansen https://digitalfire.com/material/vinegar

[Babs]

3 hours ago, PeterH said:

Tony Hansen https://digitalfire.com/material/vinegar

Then it may well help Tina. Test and see

[Tina01]

10 hours ago, Babs said:

Then it may well help Tina. Test and see

That's weird! quote from the the link:

"Vinegar is also used in clay bodies to increase acidity to improve plasticity. The acid works to neutralize sodium ions (from water, leaching feldspars) that tend to deflocculate the clay. Excessive acid may tend to dissolve more feldspar or nepheline syenite negating the effect."

but @glazenerd told me the opposite. or my recycled clay was too much acidic in the first place, or I have trouble understanding it. 

but a recap:

there were lumps in soaked clay even after a week:

putting it  in a water+baking soda helped to disperse:

thinking the clay was acidic, I assumed that the new clay I've found is also acidic, and after the failure with bentonite, I made another batch from it but I also added 1 tablespoon of baking soda to 700g of clay. It had a  subtle reaction (fuzzing). Now I feel it's very hollow and soft, weighing 650g at a clay consistency. (there was some inevitable losses here and there but not that much).

anyone knows how much it's off scale?

comparing recycled (left) with new+baking soda(right):

but I didn't realized I did a big mistake by adding baking soda soda until I saw the pervious clay:

it's covered with salt.  : ( That's gonna happen to the new bach also. : (

so again I run another test, mixing with dissolved baking soda and vinegar separately. 

with baking soda:

not so strong reaction but still fuzzing. 1/2 tblsp in 1/4 cup water dissolved as much possible. 

with vinegar:

very strong reaction, 1 tblsp vinegar in 1 tblspn water.

So it reacts with both, I dont know what's the PH level!

after settling down it seems baking soda (left) still was more successful to disperse the particles (smooth top):

Edited November 9, 2022 by Tina01

[glazenerd]

37 minutes ago, Tina01 said:

That's weird! quote from the the link:

"Vinegar is also used in clay bodies to increase acidity to improve plasticity. The acid works to neutralize sodium ions (from water, leaching feldspars) that tend to deflocculate the clay. Excessive acid may tend to dissolve more feldspar or nepheline syenite negating the effect."

but @glazenerd told me the opposite. or my recycled clay was too much acidic in the first place, or I have trouble understanding it. 

 

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

[glazenerd]

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

[Tina01]

19 minutes ago, glazenerd said:

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

@glazenerd

Sure Tom, please view the pervious post , You posted this while I was editing that one to add more details.

[Tina01]

28 minutes ago, glazenerd said:

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.

That would be a huge favor!  (discard the old reddish clay as I can't find the exact same one and you already know that it was from a couple of years ago). but for the greenish one I can buy whatever amount I want. 

Also the weird thing regarding the scale is I already tried that before, but those small scales are hard to find,  unfortunately if you ask for them they give a look as if I'm a drug dealer (some even ask for it!). But I will try again for sure!

[glazenerd]

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

Edited November 9, 2022 by glazenerd
typo

[glazenerd]

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

[Babs]

On 11/9/2022 at 11:55 PM, glazenerd said:

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

Typo back a bit

AmphoTERIC is what you need.

What is Tina's source of water?

Could be  alkaline already?