Making clay 101

[Matt Oz]

 

 I've never even seen 140 mesh. That's really odd.

 

Me either.  Strange.

 

best,

 

......................john

 

 

I have ten pounds of 140 mesh, one of my suppliers carries it, don't remember what I was going to use it for. Their finer mesh is 270, it is odd.

[Biglou13]

 

It's a by product of epk production...... Silica sand. 140 is the finest they stock.

I ve used percentage of 140 with 300.

Bust mostly just used the 300

I guess the supplier here doesn't have enough people making clay.

I thought I posted about larger silica and If it would still melt in.

Are you saying not to use it?

The one time I used the 140 with 300 clay worked fine, but only a 3 day wood firing, another person, raku, and some tests at cone 6. All came out ok

I m thinking larger particle might contribute to the particle size issue.

 

The slightly modifies 12d recipe has 3.5 % absorption at cone 6ox.

The 12d*. Recipe which adds fire clay. Has 2.5 % absorption.

[Biglou13]

My recent mud adventure had me mixing my slop bucket as percentage water volume with the majority and dry portion of this mix being the flash (ahhhhhaaaaa) recipe seen a few post

 

http://community.ceramicartsdaily.org/topic/4039-making-clay-101/page-4

 

Slop bucket consists of laguna 900 and the 12D bodies, prolly more laguna 900. Slop bucket included trim, fresh rejects, green rejects bone dry, and splash pan slop (ok I'm getting close to throwing with out one), and that bucket wast starting to get quite "game-y"

 

It ended up being a 66 pound wedging job.

 

It was made using slurry method as seen before.

 

Usually the slurry method produces wonderful feeling bodies.

 

The batch has a peculiar characteristic. It feels moist appropriately moist in wedging,,feel etc....

 

It is not short.

 

It it well wedged.

 

On the wheel it feels "manly", thick and unruly, it's acts like a body that is dry, and overly dense. It really fights when when centering, coning up and down, It is not dry. But is stiff and bratty while coning up,and down. And doesn't like centering. It doesn't feel like porcelain. And it doesn't have that creamy stoneware fell like before.

 

One good characteristic is that it holds very strong wide, horizontal ish angles. Think think lucie rie meets Ido style bowl, I usually pull mostly vertical then open and shape with rib, This clay allowed to pretty much pull to shape!!! But is stiff and bratty while coning up,and down. It doesn't feel like porcelain.

 

I definitely is not short, just unruly, It like a bratty kid.

 

I going wedge and spray a few blocks, place a damp rag and "cellar" and age them.

And wet and wedge some next studio visit.

[Biglou13]

Started from another thread..........

 

 

Does a Porcelaneous body with some ball clay, say 15 to 25 % still count as porcelain.

One of the classic formulas is 25 porcelain 25 ball 25 spar 25 silica.

Does helios have a greater than 15% ball clay?

I want to make sure I get the whole porcelain experience. I have yet to make a porcelain with less than 15% ball.

 

IMHO, if it has ball clay it's not porcelain, it's white stoneware. That's the dividing line. People add ball clay to make it more plastic and supposedly forgiving, but ball clay ruins everything that makes porcelain so unique and wonderful. Helios is a true English grolleg porcelain, no ball clay.

I've found 2 recipes on line that have no ball clay?

 

Does anyone else have tested recipes for cone 6 porcelain?

 

Found a recipe that has more flux than kaolin, maybe a new class of clay needs naming.

 

I found a recipe that had small percentage of saggar XX. since some people call xx a fireclay, some a ball clay. Does xx lower the recipe to dilettante level?

 

Ps. I costed out one of my clay bodies....... Because of its cost. I'm debating if it is really worth it. To make clay. While amazing a beautiful. Im willing to spend .03$. More and buy a store bought clay that is close in finished effect. The slightly modified modified 12d clay. I will continue to make. No commercial clay matches the effects in woodfire, and is inexpensive.

[Biglou13]

May 2013 I posted here..... Having never made clay....... Less than a year later...... I own a walker pug mill/mixer, And am making my own locally sourced bodies.....with great success.....

 

This batch was approx a 300 pound experiment/test...... Not sure if it was an ignorant, Or enlightened moment. Results to be posted soon. It did tolerate rather abusive/ crash drying to leather hard state. My goal is a white as possible porcelain -ish cone 6 production quality clay....... I suppose that means make today. Bisque tomorrow.....