145r - - - - - Casting in three frames
You can cast bronze mortars and similar things which release well in three frames. That is to say the body of the mortar in one, its noyau in the other, and the base of the mortar in the third one, because otherwise the cast which is there will not release well.
at left top margin
Inquire Figure
A
Cuttlefish bone
You must not heat the tin or lead too hot, otherwise they will burn the bone and become lumpy. And to know when it is the right temperature, dip in it a little piece of twisted paper. If it turns black without catching fire, it is the right temperature. But if it burns & catches fire, it is too hot. You can cast gold & silver, but it never comes out neatly. To cast something delicate well, it is necessary that the bone not be extremely dry, because it is rough & does not release as well & crumbles & is brittle. In any case, before you cast, dry them the bones & especially for gold, which does not react well to humidity. You will know that they are dry enough when, after having exposed the insides and the imprint to the fire, they hiss & crackle when you bring them near your ear. Now join the bones & daub the joints with a little lute and slowly dry it near the fire & cast & then shake the mold or scratch the rough crannies and let it cool down before opening it. Usually one cuts the bone in the middle, and the dull part that does not have half circles is more delicate and smoother to mold with, and therefore one always uses it to do the main part of the casting, the other part of the cuttlefish bone is crumbly on the inside as on the outside. Therefore one does not use this to cast delicate things which need to be molded in two places. One evens out & flattens these two halves on some piece of wood, then one rubs some charcoal on top so that it releases well. And to make sure the charcoal is evenly spread everywhere, tap the side of the hand which is holding the half bone. Both having been covered in charcoal, take the first bone that has been prepared & rounded on the edges, and having placed the medal above it, press the medal down strongly.
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