164v - - - - - Molds
For molds wherein something must be burned (away), and do not open before being reheated: do not cast before refiring/reheating. For large molds that produce large and wide casts, it is necessary to score it with strong notches so that the pitch of the metal does not run as forcefully. These will not make many burrs if they are pressed. Prior to doing so, place between the mold and the press pieces of thick felt for mittens, which will fill the cavities and protect the mold from cracking. The clamps should be placed prior to heating or drying.
at left top margin
When the ground from which you are making your earthen base to lay out your animal is too soft, the pins you place come out easily when you cast the sand and so the mold is spoilt and the design is defeated. Therefore when you know that your slab is too tender and soft, spread some hot cinders over it and blow with the bellows.
Sable
If you don’t add enough alum de plume or crocus your mold will easily crack when heated. But if your sand is mixed as it ought to be, the mold will sustain itself. You’ll know it’s of good quality when, while still hot after casting, it immoderately soaks up the water when dipped and breaks easily, because the alum and the crocus render it spongy. To the contrary, bad sand, which is composed of plaster and brick and is not well mixed with alum, breaks easily in fire and hardens in water. If possible, cast all at once.
Molds
When you cast lead, your molds must be very dry, even if the molds are large. The outside of the molds must be reddened, and it is necessary to keep them in continuous heat until they do not smoke anymore inside. Do not reheat your molds several times, but continue when you have begun and do not let them cool in the cold because they will crack. Let them cool near the fire. When your molds are still as warm as above, remark, you can put your finger into the casting gate without burning your skin. If your mold is large, it takes more time to cure and to dry, and you must also cast warmer.