089v - - - - - Sal ammoniac and alabaster
Sal ammoniac, well pulverized mou & ground dry on marble, molds very neatly & makes a very beautiful, & once mixed with alabaster, pulverized similarly, ii ℥ per lb of alabaster, makes it release well. It sufficient to moisten it in a cave or in the serain or, to be done more quickly, in a piece of paper between a wet napkin. Take heed that it does not stay for too long, for it would become so wet that it would not be good for molding in a frame, but rather in a noyau, in which you will be able to use it well as long as dries well at ease & far from the fire. Otherwise the heat makes it swell, & push the salt onto the surface, which renders it lumpy. You can in smear the medal with spike lavender oil, molding in noyau. It is better to put in 4 ℥ of sal ammoniac per lb, and moisten it in a damp place for two or three days, & so that when you take fistfuls, it holds together, without, however, attaching itself & being pasted to your hand. You will with it mold very neatly. But let it dry & reheat really well, leaving the mold inside, so that it acquires strength by reheating, for it becomes hard as stone, & and in this way is more certain to release well. Otherwise if you release before having reheated it, there would be danger of it crumbling in some place, because of its delicateness & fineness, even if the medal of high relief. Once you have molded with it, pulverize it as before and put it back in dampness.
at left middle margin
All sand that releases well has body & sticks well. Ammoniac is fat and a va however, is areneux which makes it release well. There is no better bond than salts appropriate for metals, for once mixed in powder, they get moistened together & dry &reheat together.
Glassmaker’s white sand from the mine, mixed with sal ammoniac
There is found in Cominge, near the town of Aurignac, a sand, white mai, like salt, and lean, that glassmakers & potters use, which renders impalpable crushed on porphyry & is easy to crush. And once crushed, it resembles calcined alabaster. It molds very neatly, and I have not found any that molds as delicately as this one for low relief. It is excellent to mold en noyau without a frame, having crushed it impalpable with gummed or pure water on porphyry, then placing it, thick as mustard or a little more, on the medal, smeared with a oil either olive, walnut, even better spike lavender. But to do it better mo, let it dry by itself, without fire, for one or two days. Although, if you are in a hurry, you can heat it well, & it will not crack, if it is not put on too lightly. It is true, being thus suddenly exposed to heat all at once, it makes some holes & bubbles, which it does not do when dried in the cold or at ease, rather than being reheated. Once dry, reheat it & it will withstand several casts.