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tile sandwich': was 'warped tile

updated thu 4 jul 02


Stephani Stephenson on wed 3 jul 02

I have myself tried 'layering' finer grained and coarser clays together in
relief molds. I tried this when I had a design which was very fine lined,
which would have been obscured by coarse grog in the sculpture body I was
using. I poured slip into the mold, enough to cover the relief, about 5 mm.
I then let it stiffen before tamping in the regular clay body. Both clays
were the same , with the exception that the grog had been strained from the
first. I tried this for only one project though . It was successful, but I
never experimented much further with it.

In looking up the history of Maw and Co. I have read about their innovation
and continual attempts to experiment and improve tile production methods. It
strikes me that over time we try so many methods, especially during periods
of discovery or rediscovery. Yet only the most viable and successful ways
survive to become the acknowledged and 'accepted ' methods of production
. Especially when ttile making in England grew from a 'cottage' or 'studio'
craft into a large scale 'industry'. But how many lesser known inventions,
methods and processes were discarded? It is like going to an automobile
museum and seeing all the fascinating early models which never survived.

Your post caused me refer to 'Architectural Ceramics' by David Hamilton . He
describes a tile which sounds like the one you have.
In discussing encaustic tile, he describes alternatives to dust pressing,
talking about problems of shrinkage, etc. when slip is used in combination
with moist clay:

"An alternative method is to produce an open-topped mould, with the image
intended for the face of the tile in relief on the bottom. The clay is cast
as a thin layer, allowed to stiffen, and then backed up by pressing plastic
clay into the mould. when leather hard the tile is removed and the hollows
on the face of the die filled with clay of a contrasting color. when this
too is leather hard the surface of the tile is planed level.
Some nineteenth century tiles made by this type of process are laminated
with the clay on the top of the tile repeated on the bottom. this would have
the effect of reducing the warping of the tile due to the differential
shrinkage of the surface clay and the tile body clay"

on P. 122 of the book, there is a cutaway section of a tile made in this
way much like the one you describe,
The surface layers provide the receptive surface for decoration, the
central layer provides the physical strength necessary for a paver or other
tile, and the drying qualities. also in the photo the reverse side of the
tile is spiked, to improve drying and fixing.
It would seem to me that rather than using slip on the surface layers, a
finer grained moist clay could be used.
I never would have noticed that particular paragraph had you not mentioned
your tile.

I also roll out a slab then press into molds, hoping I get the best of both!
but the square I cut is slightly larger than the mold, so I get the
sensation I am compressing it slightly as I put it into the mold. I often
will 'square up' a larger relief tile after it is released from the mold,
by taking sections of 2 X 2 wood and gently , firmly and quickly, pressing
the sides in slightly. I remove relief piece from the mold when still wet,
shooting a bit of compressed air in between the clay and plaster.
I do make relief tiles . I worked as a hand builder and sculptor for a
number of years, working primarily with slabs. In 1999 I started working
with a tilemaker named Laird Plumleigh, and began learning more about the
craft . Plumleigh has been making tile since the late 70s and uses a ram
press and presses moist clay. He does quite large pieces. Last year I
helped to complete a 'green man' model and mold which measures 4 1/2 feet by
2 1/2 feet, definitely the maximum the press can handle.

I myself continue to work with hand building and pressing methods. for
glazing I often use a polychrome technique , using fairly thick viscous
glazes, bulbed on or applied by brush in a flowing method, onto greenware
(once fired) as well as bisque ware. I also am doing more and more
architectural work using handbuild ing methods in raw terra cotta, as well
as clay decorated with stains, engobes and glazes. I have a buff, a red and
a white body I use, with most of the work done in the red.I am forever
trying to improve my glaze palette. I also make tile for restoration
projects , in this case replicas and restoration of 'early ' California
tile, which is from the early 1900s, not very early' by your country's
standards! I have never been to Great Britain, but am learning more about
the history and innovations in tilemaking from there, though it is by book,
for now!!!
also find I am drawn to bricks and brickwork and am thinking about
incorporating into my own designs.
Oh great, BRICK! another weighty passion!!!!!!
Stephani Stephenson
Carlsbad CA

Hamilton writes:

Alistair Gillies wrote:

> >Do you think the outer layers of finer clay were clay slips, i.e. liquid
> >clay applied to the inner layer of grogged clay?
> >Or do you think that they were regular moist clay ?
> I think that slip would have far too much water in it and would have
> cracked on top of a plastic clay, also the lines where they join are
> exactly like you would expect from two plastic clays being pushed
> together.
> >I winder if the outer smooth layers were for improved impermeability,
> >glaze respinse, etc?
> The middle clay certainly would not have accepted the precision of the
> pattern that was impressed and the middle clay is very rough - although
> the composition is basic, from the top this is a highly sophisticated
> product.
> >As to warping, I have found that hand pressing moist clay into open
> >faced plaster press molds works well.
> Yes I have used this method a lot - both whilst producing restoration
> tiles for the Ironbridge museum and now I am using this technique to
> develop a range of decorative building fronts and products based upon
> architecture - use a mold to make a basic shape [front, roof, windows,
> doors] and then add half timbering, brickwork etc by hand.
> >It seems to me that a pressed tile is less prone to warp than a rolled
> >tile.
> Perhaps, though at present I am rolling out a slab and then pressing -
> does this mean that I get the best or worst of both worlds?!
> Do you make relief tiles?
> How do you decorate?
> All the best
> Alistair
> AGP Studio
> 01952 882909
> 07973 866198
> [The builders are still working]