Clay Bodies

[Bioman]

Had something interesting occurred recently.  As a new Potter, I have been struggling for months with pulling vertically and was starting to feel I was hopeless.  My pulls tend to flair out no matter what I do beyond the initial pull.  I have had some vessels collapse.  I have watched a dozen techniques on youtube and basically, none worked well.  

 

So I decided to try a new clay body from my local supplier who is also the manufacturer.  To date, I have been working exclusively with their white sandless, grog-less, mid-fire body.  So I tried a red sanded/groged mid fire body.

 

Presto-chango.  Suddenly everything I previously tried that did not work started working and working very well.  This new clay body feels much moister so I need to wet the clay less to do pulls.  It does not grab, it does not easily collapse it feels very plastic.    I am going from forms that tended to be whatever they wanted to come out as to more reproducible. 

 

Here is my question as I intend to move forward and try more clay bodies.

 

Is the grog/sand making the major difference and or do darker clays tend to be easier to work in and of themselves?  I don't want to give up on white body clay as I like that it does not effect the glaze colors as much.  Can grog/sand be added to white bodies with success?  

 

Any observations are appreciated.

[Callie Beller Diesel]

I say to the new potters out there: embrace the grit!!

I know some are afraid of the "ouch" factor on the wheelhead, but some clay bodies that have a wider range of particle sizes are easier to throw for the beginner than a processed clay that's made from all air-floated particles (*cough* bmix*cough cough*).

 

You can find white or cream burning clays that are less processed, are made from a variety of materials with that wide range of particles and have grog or sand in them. It's a bit of work, but you can indeed wedge grog into a smooth, white boxed clay. Go with a combo of fine and medium grog to start, and see what you like.

Alternately, if you love the throwing properties of your red clay, but want the glaze look of the white, cover your red clay pots with a white slip. It's a tactic potters have used for centuries the world over.

[Joseph Fireborn]

Just find a white clay body that has fine grog in it. What company does your suppliers sell around you? We could give recommendations.

[alabama]

Hey,

Since you're in the Republic of Texas, try Trinity Clay in Dallas. I use the Eastern satellite warehouse in Florence, Alabama. They have always been helpful.

In turn I give them vessels for Empty Bowls.

See ya,

Alabama

[Bioman]

Just find a white clay body that has fine grog in it. What company does your suppliers sell around you? We could give recommendations.

My supplier is Armadillo in Austin Texas.  The carry their own brand and Laguna.  I was using Laguna from another supplier in Dallas but was getting dried out boxes when I bought Laguna clay, so I stopped using them as a supplier.  When I went to Armadillo I decided to try their house brand.  The Cinco Blanco is what I have been having issue with.  Their Buffalo Wallow (red clay) with grog is what has been working very well.  The problem with Texas is it is so big; I have to travel two hours minimum to any supplier.

[Bioman]

Hey,

Since you're in the Republic of Texas, try Trinity Clay in Dallas. I use the Eastern satellite warehouse in Florence, Alabama. They have always been helpful.

In turn I give them vessels for Empty Bowls.

See ya,

Alabama

I think I have seen Trinity advertised; they are an all in-house brand place, correct?

[MatthewV]

Softer clay is easier to learn on.

Generally a fine sand or grog helps too. The coarse particles give strength.

Using lots of water makes it easier to control the clay.

 

Everyone had their first wheel pieces flop.

 

 

...and after years of throwing, use stiff clay and almost no water. I also predict many people here could throw cream cheese into a basic shape on the wheel.

[Magnolia Mud Researdh]

Try the Armadillo cone 5 porcelain as a white clay without grog.  It is smoother than Buffalo Wallow (BW) and is a good white.  I have used both including the cone 5 porcelain as a slip over stoneware without a problem. 

 

  BW is probably a better clay for learning to throw.  It fires to a nice tan in reduction.  I don't know what it looks like in oxidation.   

 

LT

[neilestrick]

Generally a fine sand or grog helps too. The coarse particles give strength.

 

 

Coarse particles help the clay hold shape during throwing, but they actually reduce the strength of bone dry and fired bodies. Not to the point that it's problem, but fine-grained bodies have greater dry and fired strength. Grog and coarse clays, have a huge impact on how forgiving a clay body is. The problem with white stoneware bodies is that they have poor particle size distribution. That is, everything in them is fine-grained. Having a variety of particle sizes makes clay bodies easier to work with. Imagine the particles of a white stoneware body as a room full of marbles- they can only pack so tight since they are all the same size, and all the spaces in between are filled with water. Now, imagine a stoneware body with a variety of particle sizes in the same way- first we fill the room with basketballs. In the spaces between the basketballs we can fit golf balls. In between those we can fit marbles, and between those we can fit BB's. There's not a lot of empty space left to be filled with water. The clay body is more dense with actual clay particles, with lots of surface contact between the different sizes of particles.

[Bioman]

Diesel

Alternately, if you love the throwing properties of your red clay, but want the glaze look of the white, cover your red clay pots with a white slip. It's a tactic potters have used for centuries the world over.

 

 Not clear on how to do this.  How do you apply the slip?

[Bioman]

 

Generally a fine sand or grog helps too. The coarse particles give strength.

 

 

Coarse particles help the clay hold shape during throwing, but they actually reduce the strength of bone dry and fired bodies. Not to the point that it's problem, but fine-grained bodies have greater dry and fired strength. Grog and coarse clays, have a huge impact on how forgiving a clay body is. The problem with white stoneware bodies is that they have poor particle size distribution. That is, everything in them is fine-grained. Having a variety of particle sizes makes clay bodies easier to work with. Imagine the particles of a white stoneware body as a room full of marbles- they can only pack so tight since they are all the same size, and all the spaces in between are filled with water. Now, imagine a stoneware body with a variety of particle sizes in the same way- first we fill the room with basketballs. In the spaces between the basketballs we can fit golf balls. In between those we can fit marbles, and between those we can fit BB's. There's not a lot of empty space left to be filled with water. The clay body is more dense with actual clay particles, with lots of surface contact between the different sizes of particles.

 

 Great explanation Neil

[giltex]

Bioman, I had about the same situation as you.  I use a lot of Cinco Blanco and then I found B-mix with grog at Trinity.  I can get height and thinness with it.   It's worth a drive up to Big D then lunch in Deep Ellum.  I alway call first to make sure they have a stock on hand.  They usually will set aside my order. 

[rayaldridge]

 

Diesel

Alternately, if you love the throwing properties of your red clay, but want the glaze look of the white, cover your red clay pots with a white slip. It's a tactic potters have used for centuries the world over.

 

 Not clear on how to do this.  How do you apply the slip?

 

You can apply slip any way that you would apply glaze-- dipping, pouring, spraying, brushing.

 

There may be some technical issues with applying slip, because it has to be formulated to fit the body and the state of the body when it's applied.  I apply slip when the pot is leatherhard, sometimes by dipping, sometimes by spraying.  I work with porcelain, so I can make slip from the body I use, and as long as it's not too thick, I have no fit problems.

[Callie Beller Diesel]

 

Diesel

 

Alternately, if you love the throwing properties of your red clay, but want the glaze look of the white, cover your red clay pots with a white slip. It's a tactic potters have used for centuries the world over.

 

Not clear on how to do this. How do you apply the slip?

I have recipes for decorating slips that you mix, but I don't use them these days. I actually found two clay bodies that are pretty compatible with each other shrinkage-wise, one red and one white. (Tony Hanson does the formulating for Plainsman Clays, and I use their product because it's in my back yard. They make a lot of their technical information available on their website.) I thinned the white clay down and apply it with a brush once the red clay pot has stiffened up slightly, just because that particular red clay doesn't like absorbing a lot of water all at once. But depending on your clay body and slip recipe you can apply anywhere from fresh off the wheel to bisque ware. I want a bit of texture in the white slip over my red clay, so I use a brush with some stiffness to it, but if you want a perfectly smooth application, I'd thin the slip down to glaze consistency and dip the piece while firm leather hard.

 

Edit: if you dip like this, the pot will rehydrate somewhat. Some clays take to this process better than others, but if you're using a clay body with that wide range of particle sizes, it's more likely to take the abuse than a porcelain, or a porcelain-like stoneware.

[Bioman]

Much to explore.  Thanks to all for the input.