Let us take another method of casting similar to the last; I have
tried it often and found it splendid; ’tis this: You take some fresh,
finely powdered and ground gesso, and you grind in like manner, & mix
with it, a little brick dust, two-thirds of the latter to one-third
of the former. Mix them well together with clean cold water into a
paste; then take a hog sable, & working with its softest part, paint
over your wax model as you did before with the clay. This time you
put it all on at one go, because as you gradually paint along with
your brush, the gesso as gradually sets,[157] so that you can soon
lay it on to a finger’s thickness with a wooden spoon. Then you bind
the mould with fine well-tempered iron wire, weaving it all round,
in and across, and, taking the thick rest of your gesso that has not
been passed through the sieve, you moisten it with a little water
& cake it on to the mould as before, to the thickness of a knife’s
back, till all the iron wire is well covered over. Of course, the
larger your mould is the larger must this shell of gesso also be
proportionately. You will do well, too, unless pressed for time in
finishing your work, to let the gesso dry a bit in the sun or in a
warm and smoky corner, so that all the moisture leaves it. Then you
put it over a slow fire and melt out the wax as you did in the former
process; let the fire grow greater when the wax has all melted out,
& bake the mould just as you did before with the earthen mould. This
is a good and an expeditious way to work in, and very useful if you
want to finish anything quickly.
FOOTNOTES:
[157] _Rappigliare._