Very thin

[Erika gof]

hello everyone.

I am hoping you might be able to help. I am wanting to make VERY thin sheets of clay so they are like paper. Firstly what kind of clay would I use. I’ve seen porcelain paper clay as one option/ I also wondered if I could pour porcelain slip onto a kiln shelf and let it dry on that?  
appreciate any suggestions

Erika

[Babs]

I think the kiln shelf will grab your clay slip and it will crack...

[PeterH]

22 hours ago, Erika gof said:

I am wanting to make VERY thin sheets of clay so they are like paper.

I'm certain you will enjoy experimenting with paperclay.

Just measured my printer paper, it's 0.06mm thick (a stack of 500 sheets measures 3cm). I cannot see you getting anywhere near that.

OTOH playing with home-made paperclay years ago I achieved 2-3m very easily with a rolling pin. I just rolled it out on under a cloth on a slightly porous surface and draped it onto a balloon. Handling thin sheets, especially when drying, may be an issue.

Pouring slip seems to be trying to cast it. I cannot see you getting thin sheets this way -- or getting them off the casting surface either.

Weakly related article.
THE MAKING OF PAPERCLAY PORCELAIN BANNERS
https://www.grahamhay.com.au/harrison1998.html
I mention it because he achieves 1.0-1.5mm with rolling. Which I suspect you could do with most paperclays.
Using a light weight cellulose/cement batt as a backing, spread a jumbo garbage bag over the batt, held in place with paper clips. Spead a layer of paper clay mix fairly evenly over the plastic sheet with a spatula. Place another sheet of plastic garbage bag over the top and roll out the clay in all directions with as much pressure as you can muster until it oozes out off the batt on all sides. Alternatively, the batt can be placed on the slab roller and reduced in that way. Keep rolling until it is as thin as you can get it. 

---

PS Not relevant to you, but an interesting idea I haven't seen before, using ceramic fibre to strengthen the clay during firing (after the paper has burnt out). He apparently needed to do this because he was using very highly/deeply textured sheets.
Firing is to Orton Cone 8 in 4 to 8 hours, depending on the decoration. If the marks are many and vigorous, a longer firing is required to stop the tile splitting up along the incisions. This is why the ceramic fibre is added, as it doesn't bum out like the paper but persists. The paper does a sterling job at room temperature of binding the surface together but the tell tale waft of smoke at 250,C spells its end, and that is when the normal paperclay tile will crack if the fibre isn't added, as the fibre remains intact until elevated temperatures resisting any tendency in the tile to crack apart along the stress lines created in the decoration. Eventually the ceramic fibres dissolve into the ceramic body glass, which is created by the high proportion of nepheline syenite in the recipe.

 

[Shane]

Hi Erika,

In the book Contempory Porcelain there's an artist called Ole Lislerud who was making large panels (100x80cm @ 3mm thin) by pouring porcelain slip down sloped plasterboard with wooden battens acting as retaining walls. There's quite a bit of information in there about his methods but it's very advanced ceramics and would probably involve years of tests to replicate. Maybe paperclay would make it easier, or more difficult, who knows.

[PeterH]

Interesting to be reminded of prior work, but from pp74-75 of the 2nd edition of Contemporary Studio Porcelain by Peter Lane (2003).

The methods used to make the components for constructing his sculptural installations were developed during a ten-year period of intensive experimentation and intensive research.
...
The procedure of actually casting thin slabs of porcelain is the the most difficult part of the whole process of manufacture because small mistakes can create big problems. The most common faults resulting from incorrect casting are: cracking, warping, and distortion with corners curling to destroy the flatness.

The details of the process cover about a page of A4.

Rolling paperclay seems likely to be a lot easier and more fault-tolerant.

PS If you are interested in the book, it's available from A$40 via
https://www.bookfinder.com/search/?full=on&ac=sl&st=sl&ref=bf_s2_a1_t1_1&qi=iA,O6ra27IBsie2OptRYjTAhne4_1702997710_1:9810:16802
... check against other sources such as Amazon

Edited December 19, 2023 by PeterH

[PeterH]

You  may find these of interest if you are going to make your own paperclay.

HOW TO MAKE PAPERCLAY | Chris Campbell
http://www.ccpottery.com/colored-clay-lessons--chris/how-to-make-paperclay-.html
Great if you have a heavy-duty mixed. If you don't you may have to resort to adding the damp paper-pulp to a pre-made thick clay slip, or adding dry clay powder to  a wetter paper-pulp mix. In either case it will take longer to dry on a plaster slab due the the greater water content.

Making Paper Clay Storage Easier and Less Stinky
https://ceramicartsnetwork.org/daily/article/Making-Paper-Clay-Storage-Easier-and-Less-Stinky

[Jeff Longtin]

Over the years I have, on occasion, attempted to clean a bristle brush, that is covered in porcelain slip, by brushing it against a plaster mold. The resulting thin layer of slip dries quickly and shrinks from the plaster surface quickly as well. I would suggest this method for producing a thin porcelain slab. 

Give it a try. You'll find it an interesting method to play around with.  You have to brush on additional layers soon after the previous one has stiffened but with patience you can create thin porcelain sheets. 

How you prevent them from warping, as they dry/stiffen, is completely up to you but at least I've given you a starting point. (Are you looking to make flat sheets or is a slight warp acceptable?)

Good luck

[Erika gof]

Thanks everyone. Success so far but yet to fire the sheets. They have dried beautifully. Fingers crossed