12 
11ERAM1C STUDIO 
TIN-ENAMELED WARE 
Charles F. Binns 
[Second Paper] 
F)ERHAPS a few words of explanation should be added 
* with regard to the soaping of the plaster mentioned last 
month. This soaping is necessary in order to prevent two 
plaster surfaces adhering to each other. New plaster 
poured upon old will unite with it so that the two form one 
block unless some kind of a greasy surface be interposed. 
Shellac or oil would answer but there is nothing more con- 
venient than soft soap. A packet of "Pearline" is pro- 
cured and on it will be found directions for making soft 
soap. A small quantity can be mixed and this is a great 
convenience. A vessel to contain the soap, another of 
clean water, a small paste brush and two soft sponges are 
provided. One of the sponges is reserved for the soap and 
the other for the water. 
The plaster dish of which the reverse or "case" is to 
be made is brushed over thoroughly with the soap jelly 
and wiped off with the soap sponge. The water sponge 
is squeezed nearly dry and the soap thoroughly washed off. 
Then a second coat with the brush, wiped off with the soap 
sponge and washed with the water sponge as before. 
Then a third application of the soap and a final polishing 
with the soap sponge but this time the water sponge is 
not used. The plaster should now show a smooth and 
slightly greasy surface and is ready for the new mix to be 
poured. A little practice will show when the soap has 
been applied sufficiently. New plaster requires three or 
even four treatments with soap but afterwards, if the 
same plaster block is used a second time, one or two applica- 
tions are sufficient. The mold or dish which has been 
soaped cannot now be used for the drying of clay. The 
pores which constitute its value have been closed. 
The "case" is now ready for making new molds and 
can be used indefinitely. It takes the place of the clay 
mound on the turntable and is always at hand when new 
molds are needed. The metal band is tied around it and 
the plaster mixed and poured exactly as in the first case. 
The newly poured plaster should be allowed to heat which 
it will do in a few moments and if there be any difficulty 
in dividing the two parts the blade of a knife may be ap- 
plied at the junction and one or two taps upon it with a 
light hammer will bring about a separation. The new 
plaster must be well dried before it will be of service in 
drying the clay. 
To produce successful work in tin-enameled pottery 
the whole design should be completed before the form is 
begun. Much depends upon having shape and decoration 
in agreement. There are certain forms suitable to por- 
celain and certain others proper for faience and due regard 
should be had to this 'fact. A correct harmony in all 
parts of the design is essential to the production of a pleas- 
ing result. In both throwing and building the beginner 
will find a difficulty in persuading the clay to follow a 
chosen line. It is well in such cases to pay attention to the 
shape of the inside of the piece. The outside can be changed 
when partially dry, the inside cannot. In order to help 
this the line of the inside should be indicated on the draw- 
ing and a plaster "rib" cut to this line. In pouring plaster 
a little may be spilled on a flat surface so as to form a sheet 
about half an inch in thickness. The line of the shape can 
be marked on this and with a knife the form can be cut out. 
This form is slipped inside the vase as the shaping goes on 
and serves to keep the line where it is wanted. On the 
wheel the same rib serves as a guide and while it is held in 
the left hand the right hand guides the clay from the out- 
side. In the case of a jar or vase with a narrow mouth 
the rib must be cut in the shape of a sickle or crescent so 
that it can be removed from the opening. 
Another convenient tool for use in throwing is a flat 
piece of wood about ten inches long with a slightly enlarged 
end, something like a small tennis bat with a very long 
handle. This greatly facilitates the shaping of the inside 
of vases in which the opening is too small to admit the hand. 
In preparing the body, red clay need not of course be 
insisted upon, a white clay is quite as good, if not better, 
but white clays are more difficult to procure and much 
more expensive. There is moreover a certain pleasure, 
not only in making this ware as it was originally made 
but in using the commonest materials to produce fine 
results. 
The pottery being duly made and dried it must be 
fired in biscuit. The lime in the clay will reduce the shrink- 
age considerably and will make the biscuit very porous. 
In fact it must be so. If a hard burn be given and the 
ware brought to vitrification not only will it not take the 
glaze so well but there will be a danger of the pottery col- 
lapsing entirely, for lime, while it is refractory up to a cer- 
tain point, melts down a clay with great rapidity when 
that point is exceeded. 
The next thing is the preparation of the glaze and 
here every worker must be prepared to do some experi- 
mental work. No two clays are exactly alike and while 
an enamel may be given which works to perfection under 
a given set of conditions it is by no means certain that 
with another clay and under other conditions the results 
will be as good. 
The following are both pure white opaque enamels: 
White lead 33 White lead 34 
Whiting 9 Whiting 8 
Feldspar 21 Feldspar 15 
Flint 17 Zinc oxide 3 
Tin oxide 20 Kaolin 3 
Flint 17 
100 Tin oxide 20 
The materials can all be bought ready for use from 
the Roessler and Hasslacher Chemical Co., 100 William 
Street, New York. Feldspar, flint and kaolin are the 
same as those used in bodies. 
If a mill is available the mixture can be ground but 
care must be taken not to grind too fine. The best plan 
is to weigh out the white lead, whiting and tin oxide and 
to grind these for an hour, then to add the other ingre- 
dients and to grind for ten minutes more. The glaze thus 
prepared will have a slightly gritty feeling and will be less 
liable to crawl and peel off than one which is ground fine. 
In preparing by hand no fear of fine grinding need 
be felt. The difficulty will be to secure a perfect mix. 
A brass sieve should be procured having eighty meshes to 
the linear inch. Each material is weighed out, mixed 
separately with water to a thin cream and poured through 
the sieve. Lumps must be rubbed through but gritty 
particles rejected. The sieve should not be washed until 
after all the ingredients have been rubbed through. The 
batch is now thoroughly stirred and poured through the 
sieve two or three times. This insures a perfect mixture. 
Set aside for a day there will be found some clear water 
on the surface of the glaze. This must be carefullv si- 
