069v - - - - - [continued]
The sand near my area is very excellent. But one ought to, in order to make an excellent work, take it fresh, which has been used. For it dries out after having been cast several times & is lean & has no body. If you cast some fine work which has hardly any thickness, it is necessary that your substance of copper be very hot so that it penetrates & runs. Some mix in lead with the fonte, but it is for large works & not for small ones.
Sand from oxen feet twice—burned & finely ground melts more neatly with copper, & without a chappe, than sand that I have seen. I have cast a high relief medal with it, and f with a thickness as delicate as a knife blade or a card. And being a hollow on one side, opposite the relief which was on other side.
It is necessary that lean sands be more moistened than others, namely with magistra or good pure wine or boiled wine with elm tree roots & similar things. But very fine sands, like burned linen which is fat & soft on its own, want to be applied dry.
All moistened sand wants to be very beaten & stirred in order to be ground finely \& to flatten out the clods that it makes in itself when it is bathed.
The olive oil that some mix in with beaten egg white makes it become porous.
Sand of calcined glass withstands several castings, but there are only the first ones. It also becomes porous.
Latten comes out on its own, but it runs too quickly. It is good to mix it with a little copper, like a quarter part, with the substance of skillets.
Founders cast well box molds up to 30 or 40 lb, but not more.
at left middle margin
It is good for big work, but for small ones it is troublesome for releasing. Il because it crumbles. It is good that it be alloyed with some fat thing which has bond such as molded tripoly or ab burned felt or sal ammoniac or tripoly & similar things.
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