106v - - - - - Casting in gold
To cast in gold, il f crocum ferri is necessary, & more alum de plume than in the following mixture. The alum de plume mixture cannot corrupt anything. The mold needs to be red & press it promptly with iron presses.
The shell of crabs & crayfish are uneasy to burn & there is a proper way of molding them.
Rats & birds can be molded, and the feet are uneasy to extract, when burnt, because they are small & delicate. The bodies are extracted more easily from the mold. The feet are cast in many times pieces.
Tiles
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Those of the houses that are not sandy seem to withstand fire better.
Tiles with which one covers houses, the hardest & firmest and recleansed of stones & large gravel, are used to p mix in with the sand et for molding. But, before, it is necessary to heat them just until they have been well red for one or two hours, & pestle them & pass them finely through a sieve.
The little turtles, having just come out of the egg, are very nice to mold.
If the plaster is mixed with some dust or is not the hard kind, it bursts in the fire & causes flaws.
The hardest plaster, as was said, is the best being from stone, therefore take it raw of this kind. Crush it bienplus as finely as possible and pass it through the finest sieve or sleeve that you can. Being thusly pb fine, put it, in a good amount, in a cauldron or skillet over an open flame, & as it begins to heat up, stir it continuously, and heavy & lumpy as it is, it will become so light & so handleable that it will seem to you not to have any resistance to handlingstirring, as if it was water. Keep stirring it continuously until it returns once again to being heavy & dense, and that is the sign it is cooked. But do not reheat it until your brick and alum de plume are reheated & your clay circles are done. For it needs to be the last one reheated & when all the rest is ready, for the less plaster#
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# remains reheated, & plus the quickest it is put to work, that is the best, for it sets more quickly. One ought not reheat it until you want to mold. And to reheat it, put it, as finely ground raw powder, in a cauldron on ash a clear flame & do not make it neither too strong nor too violent. Always stir with a long stick, to avoid the vapor, turning it around the cauldron & in the middle, in a figure 8. At the beginning, you will find it heavy difficult to stir, because it is full of moisture. As it heats up, it will start to throw off some bubbles at the edge of the cauldron. And finally it will become like liquid & mealy & like bran & boiling in the middle. Continue to stir continuously until you recognize that it has once again become heavy Figure
Alum de plume is the one that gives good binding to sand.
Crocum ferri is appropriate for gold. It is it, once mixed within the sand, that receives it & holds it within its warmth.
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Plaster When you have it as a stone, choose the hardest bits and those which do not easily crumble away with your nail, and clean it well from powder & filth before you pestle it.
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Plaster alone does not withstand fire, but breaks up into pieces.
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Reheated plasterse ga, as is said here, keeps well one or two months well pressed in a dry place, if it’s not rainy weather. But when fresh, it is excellent for exquisite work.
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It must withstand the fire & turn red like a lit charcoal.
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