[buckeye]

Since I started all I have used is Stoneware and I am thinking of trying some Porcelain. Anyone know of a good porcelain that throws well and fairly easy to work with? any tips or advice for working with porcelain?

[dakotaslaton]

buckeye, on 30 October 2011 - 09:13 AM, said:

Since I started all I have used is Stoneware and I am thinking of trying some Porcelain. Anyone know of a good porcelain that throws well and fairly easy to work with? any tips or advice for working with porcelain?

Hey guys I'm new to the forum, though not new to potting.
In response to your question, I would highly recommend Coleman Porcelain by Aardvark Clay. It is a good throwing body, though it is not the most translucent porcelain in the world, if that's what you're after. I throw with it regularly and don't have any trouble. It is a ^10 clay.

[Chris Campbell]

I strongly recommend researching working with porcelain before you tackle it .... Very different to work with so take time to read a bit.

[bellonart]

If you make your own clay, I have a recipe for a very versatile porcelain body that is pure white in oxidation and offwhite/grey in reduction. It's can also fire to ^10, but is very nice at ^04 - ^6.

My experience with porcelain hasn't been as difficult as a lot of people make it out to be... one thing to keep in mind is to let it dry SLOW. Cracking is the issue. I've also yet to be very successful with joinery at ^10... It looks fine at the bisque stage, but once it high fires the joining areas become very noticeable. I'm using the slip and score technique, so maybe I need to adjust my method... not really sure how I can slip and score better. I'm not being lazy about it or anything..

[Benhim]

The Porcelain I throw is from Clay Art Center in Tacoma Washington and is called Takamori. I'm sure that doesn't help you much being in Ohio, but it's a great porcelain. The Takamori body they make is a mixture of Tile 6/Grolleg. It throws well, fires white, goes translucent and has some connection/hand building properties that most porcelains do not possess.

Most commercially produced porcelain bodies have a difficult time drying. Pots will easily S crack pretty much every time they are left on the foot to dry even slightly too long. Most commercial porcelain bodies have a difficult time standing up, and will only make small forms on the wheel because the particles in a porcelain are nearly all the same size. In contrast a stoneware has many sized particles which will much more easily stack up into a wall.

Porcelain has a memory that can be troublesome to the person just beginning to work with the material. Using stoneware you can throw something into the shape of a circle and then alter it to be a different shape. However with Porcelain the clay will move back toward it's original shape as much as it can. Usually not all the way back, just partially. This can exhibit itself in plates going in to the kiln flat and coming out curved because of how they were lifted off the bat. Or a cup that was bumped out of round during drying being put back on the wheel and trued only to warp back toward the bumped shape during the firing. Many drying and warping issues are also associated with porcelain bodies that don't occur in stoneware. The key is being very methodical, following sound techniques, drying slowly and evenly as possible and keeping the items flat during drying and firing.

All in all Porcelain is challenging compared to stoneware, but can be very rewarding. It can open up a wide array of color palette that most stoneware bodies can't achieve. There are many videos, workshops and books from which to draw techniques, tips and working parameters. I would encourage you to read a book, maybe watch a CAD video, buy a bag and try it out.

The Coleman porcelain isn't a true porcelain but a kaolin/ball clay mixture which is why it's not translucent and slightly off white. It is very forgiving to the person just beginning to work with porcelain, and a favorite body of many professional potters.

[Pompots]

I love Nara Porcelain from Aardvark. i use cone 5 but they have also cone 10. Give it a try, and i think is not as bad as lots of people thinks. Its a bit less forgiving than stoneware but once you get a hold of it is beautiful. Good Luck

[JLowes]

After working with Standard 365 Cone 6 porcelain a good bit and wondering why folks always seemed to have more trouble with it than I, my last firing stopped all that thought. I made a plate using a plaster form made for the wheel to throw and shape, then partially dry the porcelain. When I took the plate off the plaster it was firm and non-yielding, and I let it go to bone dry under plastic over a coupl of weeks. I fired it this past weekend, and as it happened in kiln loading the plate ended up on a half round shelf by itself, overhanging the edge. When I pulled the plate out it was severly warped, and a sizable chunk of the foot was plucked off by the kiln shelf (which was kiln washed by the way.) There was also a glaze incompatilibity issue on the overlap of a steadfast clear and Opulence Midnight Blue (always a good glaze before) that caused crawling of the glaze.

Fortunately for me, I have worked a lot with this porcelain and will again, but a first timer might have run kicking and screaming from porcelain forever. I may use stoneware for my plates though, lol.

John

[Benhim]

JLowes, on 16 November 2011 - 12:09 PM, said:

After working with Standard 365 Cone 6 porcelain a good bit and wondering why folks always seemed to have more trouble with it than I, my last firing stopped all that thought. I made a plate using a plaster form made for the wheel to throw and shape, then partially dry the porcelain. When I took the plate off the plaster it was firm and non-yielding, and I let it go to bone dry under plastic over a coupl of weeks. I fired it this past weekend, and as it happened in kiln loading the plate ended up on a half round shelf by itself, overhanging the edge. When I pulled the plate out it was severly warped, and a sizable chunk of the foot was plucked off by the kiln shelf (which was kiln washed by the way.) There was also a glaze incompatilibity issue on the overlap of a steadfast clear and Opulence Midnight Blue (always a good glaze before) that caused crawling of the glaze.

Fortunately for me, I have worked a lot with this porcelain and will again, but a first timer might have run kicking and screaming from porcelain forever. I may use stoneware for my plates though, lol.

John

I just wedge in some 35 mesh grog for plates.

[macdoodle]

Just got some babu to try for hand building. it has an interesting "soft " texture at greenware - would say it's made for carving- which i will try with some of the rest. Some warping on a piece I did in sections with heavy curves, some thick slip was fine some cracked a little. Takes color via oxides wonderfully- made things thick dried it very very very slow couple of weeks but still got some cracking. first two the iron from cookies ghosted on the bottom @ cone 10- but i ground it off slowly with a small engraver tool and sandpaper.
waiting for 2 pieces to come out and have one tall and thin one that i am afraid to bring into class to fire as it may be too delicate for all the rearranging that goes on in our student kilns.

[rissierae]

I always described throwing porcelain as like throwing cream cheese. You just have to get used to it, but it's fun. I tended to throw it thicker, and then trim the heck out of it!

[Marcia Selsor]

I like the porcelain from Alligator in Baton Rouge. Also Armadillo Clay has a nice throwing porcelain but I think it has a slightly yellowish tinge.
It really depends on your location. There are a lot of good porcelain clays on the market.
Laguna's Coleman porcelain throws really well.
Marcia

[gvb96]

Hi guys just wanting your opinions on a problem ive been experiencing in my lab over the past few months, for all my implant cases i use a 51% au alloy, i recently fabricated a 3 unit bridge on 2 implants and was really happy with it so i decided to glaze it and the bridge came out of the furnace with visable hairline cracks from the lingual of each abutment towards and through the lingual of the pontic, so i decided to strip the ceramic off and relayer it but this time i introduced a 8 min cooling cycle but this did not solve my problem as it happened again! The alloy i use has a corresponding cte to my ceramic and other labs around town also use this alloy with the same ceramic and have absolutly no problems. The interesting thing is that it doesnt happen on any single units i make just bridges!

[Denice]

gvb96, on 30 November 2011 - 05:50 AM, said:

Hi guys just wanting your opinions on a problem ive been experiencing in my lab over the past few months, for all my implant cases i use a 51% au alloy, i recently fabricated a 3 unit bridge on 2 implants and was really happy with it so i decided to glaze it and the bridge came out of the furnace with visable hairline cracks from the lingual of each abutment towards and through the lingual of the pontic, so i decided to strip the ceramic off and relayer it but this time i introduced a 8 min cooling cycle but this did not solve my problem as it happened again! The alloy i use has a corresponding cte to my ceramic and other labs around town also use this alloy with the same ceramic and have absolutly no problems. The interesting thing is that it doesnt happen on any single units i make just bridges!

Dental porcelain is an entirely different beast than porcelain clay but someone might have some experiences with it. I was a lab technician 33 years ago when implant technology was in it's infancy. I waxed and finished the frames but didn't work with the porcelain, when cracks would happen they would blame it on a tight angle in the frame and have me rewax it. It was still experimental then and we were working with full mouth implants. Since then the technology has exploded in that field but the first thing I thought of was stress cracks when I read your post. Denice

[Marcia Selsor]

gvb96, on 30 November 2011 - 05:50 AM, said:

Hi guys just wanting your opinions on a problem ive been experiencing in my lab over the past few months, for all my implant cases i use a 51% au alloy, i recently fabricated a 3 unit bridge on 2 implants and was really happy with it so i decided to glaze it and the bridge came out of the furnace with visable hairline cracks from the lingual of each abutment towards and through the lingual of the pontic, so i decided to strip the ceramic off and relayer it but this time i introduced a 8 min cooling cycle but this did not solve my problem as it happened again! The alloy i use has a corresponding cte to my ceramic and other labs around town also use this alloy with the same ceramic and have absolutly no problems. The interesting thing is that it doesnt happen on any single units i make just bridges!

you should probably start a new topic rather than add this to the porcelain thread. You may get a better response.

Marcia

[Red Clay]

Chris Campbell, on 02 November 2011 - 10:17 AM, said:

I strongly recommend researching working with porcelain before you tackle it .... Very different to work with so take time to read a bit.

Strongly agree. Research as much as you have time for. It will save you from repeating the many mistakes of those of us who did not.

[buckeye]

thanks everyone for your ideas and suggestions.

[klen11]

You know, we have tried porcelain, but we would have to admit that we like working with ceramic bisque fired at cone 04 better. It doesn't require as high a temperature and the glazes almost feel less toxic. Porcelain does, however, feel a lot more like a finished produce as there are less pores and it is harder than ceramic bisque fired at cone 04. The higher temperature needed to make porcelain makes it more expensive.

[ThisIsMelissa]

I, too, would like to give porcelain a try. I've seen some demos on CAD and on youtube that look so good with porcelain. And the stoneware that we use at the art house (where I take classes) is extremely groggy and it's almost painful to use on the wheel.

However, our studio only fires to cone 6. There are 2 suppliers in our area that carry a cone 6 porcelain. So, I thought about buying a 25 lb bag, just to give it a try. The disadvantage is that I wouldn't have the benefit of my clay being recyclable, since the studio only pugs the clay that they buy. But, perhaps it'd be worth it anyway.

[Lucille Oka]

ThisIsMelissa, on 26 December 2011 - 04:10 PM, said:

I, too, would like to give porcelain a try. I've seen some demos on CAD and on youtube that look so good with porcelain. And the stoneware that we use at the art house (where I take classes) is extremely groggy and it's almost painful to use on the wheel.

However, our studio only fires to cone 6. There are 2 suppliers in our area that carry a cone 6 porcelain. So, I thought about buying a 25 lb bag, just to give it a try. The disadvantage is that I wouldn't have the benefit of my clay being recyclable, since the studio only pugs the clay that they buy. But, perhaps it'd be worth it anyway.

You can always try to keep your clay isolated. May I suggest first try handbuilding with it. See how it responds to your touch. Make and fire some test tiles so you can see what it looks like when fired. Apply your favorite glaze see if you like the result. If you do, is there enough space in the studio for you to have your own small clay keeper container? Label it with your name and type of clay. This is a good way for you to learn how to recycle your own clay.

[ThisIsMelissa]

Quote

You can always try to keep your clay isolated. May I suggest first try handbuilding with it. See how it responds to your touch. Make and fire some test tiles so you can see what it looks like when fired. Apply your favorite glaze see if you like the result. If you do, is there enough space in the studio for you to have your own small clay keeper container? Label it with your name and type of clay. This is a good way for you to learn how to recycle your own clay.

I can always bring my clay to and from home. Other than "works in progress" there really isn't anywhere I can store tools/supplies.

I think handbuilding would probably be an even bigger issue. The handbuilt stuff I do is mostly with slabs. And the slab canvases are tinted by the brown-ish clay that the studio has used for years. And I certainly don't want to invest in my own canvases. Yeah, there wouldn't be a bunch of slop/slip or a lot of trimming debris that wouldn't be recyclable, but then I wouldn't be able to use the slab roller either.

I dunno. Lots to think about.