Porcelain Clay Bodies

[Ceallach]

Not sure if this is the right place for this.  If it is, then admins can whoosh wherever is best.  

I have been using a dark clay body, which I love, but have a bit of fatigue in working with the dark color....I need to work with lighter colors a bit, even if I work in two different clays.  I have done some small stuff with Coleman's porcelain and it was okay.  I have tried Dave's and fought with it the whole time.  I would like to find a nice porcelain that works for me.  

I am looking for some reviews of porcelain or thoughts on various clay body.   I do some mild altering of  thrown forms, and deep sgraffito.  I also like to do taller forms, but realize that may be more challenging with porcelain.  

Any thoughts?

[neilestrick]

@Ceallach  What cone?

[Chris Campbell]

You don’t need to go to porcelain to get lovely lighter clay bodies. While I love porcelain, it does have a learning curve and can be frustrating to anyone used to a friendlier clay. Many clays are warm, creamy and light while still being user friendly. Just a thought.

[Magnolia Mud Research]

You can use slips of white clay as a coating over dark clay.   This approach avoids some of the learning curve of using a significantly different clay body while having a built-in "deep sgraffito" capability.

I make slips from both commercial clay bodies, and from raw clay formulations (locally found dirt) by adding just enough water so that the "slip" is a thick paste.   It is a technique developed by trial and error.  The slip layer is compressed onto the substrate clay when the shine of the slip has disappeared. 

LT

[Min]

Adding to what Chris said, cone 10 B-Mix is very forgiving and easy to throw. (I find it's a much nicer clay to work with than the cone 5 B-Mix) It's not white but it's a light body, very smooth, generates a fair bit of slip while throwing and you can throw fairly tall with it. Could add a layer of slip to it like LT suggested if it's not white enough.

[Ceallach]

On 5/10/2018 at 5:53 AM, neilestrick said:

@Ceallach  What cone?

Go big or go home.  ^ 10

To clarify:

I currently do a black and white ware....porcelain  slip over black mountain and then carved and sgraffito.  I like the contrast.   I could and probably will do the black clay for a long time, but i need some visual relief if that makes sense.  I also feel like art pots/sculpture will start with black and functional with white clay....partly because i like the blk mountain bare, love the color, but any clear glaze so far turns it gray which i dont like.  The rich brown is luscious and very much about the clay being clay and not aomething else, if that makes sense. 

I am fine with porcelain, its not a new trick pony for me....i just dont have  a favorite  yet.  Ive tried dave's which fought me, colemans is nice but not sure it's the One Porcelain for me.  There is  a local mix that plucks like a son of  a buck so that's out.

I have in the past used Danish White or Geostone with good results but the last time I used the DW i had lots of cracking and the stoneware just does not give me that contrast.

Because I am looking for contrast in my work, I need the extreme of color.  Ergo porcelain.

I actually just got some small bowls out of the kiln.  They were with Colemans, with colored slip from Mason stains.  I dipped them half and half celadon and clear....i usually use a celadon but the clear was amazing on it and zinc free for better results.

I am also doing a bit of alteration where I even pull the pot in places...so the porcelain needs to be a bit more je ne sais quoi. 

HTH

[Ceallach]

Also, the porcelain carves like feshly churned butter in a halcyon dream.  So there's that.   At the mimnet i only have ^10 access or I'd use Cassius  at ^6 because it has the same carving character

[neilestrick]

For a great functional porcelain, I really like Standard 258. It's not quite as glassy as some, but throws great and doesn't have warping issues. Highwater Helios is also really nice. throws well, very white and glassy.

[Ceallach]

Neil, I am on the west coast....none of my local suppliers carry Standard clays, and shipping on clay is exorbitant.  We have coleman, frost, glacia, nara, daves in porcelain....out here, suppliers are Laguna, Quyle, Aardvark, IMCO.  Clay planet also have a few pugged clays but I did not see a porcelain. 

 

[neilestrick]

9 hours ago, Ceallach said:

Neil, I am on the west coast....none of my local suppliers carry Standard clays, and shipping on clay is exorbitant.  We have coleman, frost, glacia, nara, daves in porcelain....out here, suppliers are Laguna, Quyle, Aardvark, IMCO.  Clay planet also have a few pugged clays but I did not see a porcelain. 

 

Laguna Babu.

[LeeU]

I get cone 4-5 Cool Ice from Seattle Pottery (it's actually from Australia) and it is the most lucious white. I beleive they make a cone 10 as well. I also use Troy's cone 10 porcelain, also a lovely true white. What I make is usually hand-built, rough rather than refined, thick and opaque, often unglazed or just clear, so I can't speak to either body as far as wheel work goes.   The first pic is the troy ^10 porcelain, fired to about ^11; the incense holder is the Cool ice, fired to ^6

 

[Mark C.]

I work with 3 porcelains-daves which is a bit grayer and you said you do not like it. Babu  from Laguna -its super white and also 550 which is a grolleg porc.-super white as well-thats a laguna #WC 631

I suggest you try the later two-they all are cone 10

here's the description for 550

#550 Made primarily of English Grolleg. Contains plasticizers to make this the finest translucent porcelain available for throwing, thin slab work

Baba description-

A grolleg porcelain. Very white in oxidation and good for dinnerware

WC-428 BABU

I was friends with Jim Danish  as he lived in Humboldt for decades before moving to Far East and his clay is a white stoneware which is pretty bullet proof for throwing.I would try one of my porc suggestions

[yappystudent]

Silver Falls from Georgies (Portland/Eugene) is the second ^6 porcelain I've tried and I like it. 

[Ceallach]

Thanks, everyone.  Next time I buy clay, I'll pick up some Babu and try it.  I'm also going to try Geostone again....it's been decades, but I remember liking it.  Not sure how it will be for my current work, but local supplier (IMCO is about 75 minutes from here, and the quarry price is $10 less than the closer suppliers. 

[Mark C.]

Yoi Porcelain is the only porcelain that IMCO sells-I do not know much about it. Geostone is white stoneware.

[preeta]

If you are 75 mins from IMCO how far are you from Oakland? Because the Bay Area is the place to go.  

East Bay Clay in Richmond is famous for their ^10 bodies.  They have prepared personal clay recipes for famous local potters and are allowed to sell them. 

I have yet to visit there but I know many potters who go down there to collect their favourite clay bodies. Definitely worth a visit to talk and bring some samples home.

Does price play a factor in your choice?  Isn’t Babu pretty expensive? Esp with its shrinkage levels.  If you get geo stone would you post how it feels and glazes. IMCO in the last few years have gone through some changes which has affected their clay. I’d be curious to hear what you think. 

Leslie ceramics I think is in Oakland. 

How far is Alpha Ceramics from you? They have great helpful staff. I always end spending hour there on good conversation. 

I feel clay is a tough one. Everyone has such strong opinions on what works for them.  

Quyle clay has some nice bodies too. Another local clay manufacturer like IMCO.  Fabulous people who are highly respected among clay people.  Silverstone I really enjoy throwing with. 

[Ceallach]

On 5/18/2018 at 11:55 PM, Mark C. said:

Yoi Porcelain is the only porcelain that IMCO sells-I do not know much about it. Geostone is white stoneware.

I know.  In looking at this....i came across Geostone and remember using it eons ago.  

[Ceallach]

12 hours ago, preeta said:

If you are 75 mins from IMCO how far are you from Oakland? Because the Bay Area is the place to go.  

East Bay Clay in Richmond is famous for their ^10 bodies.  They have prepared personal clay recipes for famous local potters and are allowed to sell them. 

I have yet to visit there but I know many potters who go down there to collect their favourite clay bodies. Definitely worth a visit to talk and bring some samples home.

Does price play a factor in your choice?  Isn’t Babu pretty expensive? Esp with its shrinkage levels.  If you get geo stone would you post how it feels and glazes. IMCO in the last few years have gone through some changes which has affected their clay. I’d be curious to hear what you think. 

Leslie ceramics I think is in Oakland. 

How far is Alpha Ceramics from you? They have great helpful staff. I always end spending hour there on good conversation. 

I feel clay is a tough one. Everyone has such strong opinions on what works for them.  

Quyle clay has some nice bodies too. Another local clay manufacturer like IMCO.  Fabulous people who are highly respected among clay people.  Silverstone I really enjoy throwing with. 

Leslie is in Richmond. 

I am in the east bay....i go to Claypeople for clay, they're  25 minutes from me outside of traffic.  

i have considered getting East Bay to formulate for me, but would like to sample myself first.  

They make the clays for a local studio, none of which i like.  The porcelain that plucks I mentioned is theirs.

[Mark C.]

Most porcelains will pluck-You need to use alumina hydrate in wax or wash shelves. Just part of the deal

[preeta]

Doesn’t East Bay have a whole bunch of formulations that you can choose from to get a white body, maybe not porcelain.  

I wouldn’t know where to start myself to even make my own clay.  Not enough knowledge there.  But I do play with mixing commercial bodies.  

Now off to read what this pluck is with porcelains.  

[preeta]

Wow pluck is a new word for me. 

Sticks to kiln shelf?  From Marks reply. 

Aah found the answers. No wonder in woodfire proff put sand under his porcelain pots.  

[Ceallach]

3 hours ago, Mark C. said:

Most porcelains will pluck-You need to use alumina hydrate in wax or wash shelves. Just part of the deal

Tell me more.  Porcelains tend to be high alumina bodies, so what ia the idea?

Familar with  the alumina for salt, but this is straight  redux. 

[neilestrick]

52 minutes ago, Ceallach said:

Tell me more.  Porcelains tend to be high alumina bodies, so what ia the idea?

Familar with  the alumina for salt, but this is straight  redux. 

Porcelain is high silica, not alumina. They get very close to their melting point during firing, so they soften up a lot and will stick to the kiln shelf. I would not put sand under my porcelain, as it may leave a texture on the foot as the clay softens.

[glazenerd]

Porcelain typically runs 70-72% silica, 17-19% alumina for the target of 4:1 si/Al ratio. ( mr. Ron Roy). Porcelain usually has 50% more flux than stoneware; which is where the plucking comes in. Cone 6 stoneware runs 2.89 molar alkali and porcelain averages 3.89 molar. The more translucent the body: the higher the alkali molarity, which also translates to higher COE values. Vitrification comes with a price: plucking being one of them.

T

[Pres]

I have moved this strand to Clay and Glaze chemistry as it seems to be more relevant here than In the Studio.

 

best,

Pres