DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.19571#0217
TI
THE ARTIST'S ASSISTANT. 203
pot as before, and give them another baking among
the earthenware, and, when cold, grind them fine,
and that powder will be fit for ufe.
The clay being thus prepared, take fal-armoniac,
put it into a glafs, with water, that holds about two
quarts, put fo much of the fal-armoniac to the wa-
ter as will diflblve it over a gentle warmth, and let
it ftand one or two hours clofed up; then take your
powder of clay, temper it with this water to fuch a
confidence as to form it into balls, and make what
moulds you pleafe thereof. When you call your me-
tal, you muft make your mould red hot, and be alfo
very nimble in pouring out your melted metal.
To make moulds of clay to caft brafs or other
metals therein :—Take good clear clay, fuch as the
pewterers ufe; take alfo cloth fhaving, or fine fhort
plucked cotton, and fine clear fand, and if the fand
is not fine enough, grind it on a colour Hone ; mix
this with the clay to fuch a confidence as is fit to
make or form your moulds thereof. Your clay mull
not be made foft with water, but with firong beer,
and when you call let your mould be red hot.
If you would have a fine and fharp caft, fift over
your clay fome fine wafhed afhes, before you make
the impreflion.
To prepare moulds which need not to be heated,
•for calling metal in them :—Take fine fand, fuch as
the goldfmiths ufe ; mix it with lamp-black, as much
as you think proper ; then temper it with rape or
linfeed oil, fit to make your moulds thereof; what-
ever you caft in them, comes not only out neat and
fharp, but you have no occafion to heat your mould,
as is required in other cafes : this you muft obferve,
that your fand be very dry, before you temper it
C C 2
The
THE ARTIST'S ASSISTANT. 203
pot as before, and give them another baking among
the earthenware, and, when cold, grind them fine,
and that powder will be fit for ufe.
The clay being thus prepared, take fal-armoniac,
put it into a glafs, with water, that holds about two
quarts, put fo much of the fal-armoniac to the wa-
ter as will diflblve it over a gentle warmth, and let
it ftand one or two hours clofed up; then take your
powder of clay, temper it with this water to fuch a
confidence as to form it into balls, and make what
moulds you pleafe thereof. When you call your me-
tal, you muft make your mould red hot, and be alfo
very nimble in pouring out your melted metal.
To make moulds of clay to caft brafs or other
metals therein :—Take good clear clay, fuch as the
pewterers ufe; take alfo cloth fhaving, or fine fhort
plucked cotton, and fine clear fand, and if the fand
is not fine enough, grind it on a colour Hone ; mix
this with the clay to fuch a confidence as is fit to
make or form your moulds thereof. Your clay mull
not be made foft with water, but with firong beer,
and when you call let your mould be red hot.
If you would have a fine and fharp caft, fift over
your clay fome fine wafhed afhes, before you make
the impreflion.
To prepare moulds which need not to be heated,
•for calling metal in them :—Take fine fand, fuch as
the goldfmiths ufe ; mix it with lamp-black, as much
as you think proper ; then temper it with rape or
linfeed oil, fit to make your moulds thereof; what-
ever you caft in them, comes not only out neat and
fharp, but you have no occafion to heat your mould,
as is required in other cafes : this you muft obferve,
that your fand be very dry, before you temper it
C C 2
The