
~~~~~~~~~~~~~~~087v~~~~~~~~~~~~~~~

Sand, slate, and burned earth

Very burnt sand loses its bond. Slate is reheated & molds
neatly. Next, it is true that often it becomes porous, like burned
earth also does, like fat sand also does.


I find that one ought not to knowck on very finely ground sands, for it
shakes them loose, & make prevents them from releasing
neatly. But one ought to press hard and moisten them sufficiently.


Magistra

Founders take the roots of a young elm
when it has sap, & boil it in wine, or better yet
vinegar, and keep it all year long in a
cask.


Sand from the mine of Thoulouse

 Casting sand coming from the mine, once passed through a
double sieve, next put in with melted resin, burns &
inflames & becomes all red & inflamed like iron. Once
cold it is completely black and can be ground very finely on
porphyry. Thus having prepared it & render it
without asperity on the fingernail, I moistened it
with beaten egg glair & beat it well, until it was not pasty
but rather powdery. I found it of very good release, & molded with
it in lead & tin very neatly, but it wants to be well
reheated & at ease.

Others beat it well in a mortar, in small amounts at a
time, & thus it is pressed together and rendered very fine. Then
they reheat it moderately, only to dry it. After, they grind it dry on
porphyry. And thus it becomes as if impalpable, and not
too dried out, it and it retains body & bond of the
earth to which it is related, and is better than when it is so
burnt. Once moistened with egg glair passed through a
sponge, it releases very neatly M very
neatly in low relief, but not for figures in high relief. Therefore,
since then I have experimented lexper with
moistening it only with quite strong vinegar. It released a
figure which I could not release previously. And I believe that,
moistening the finest in the same way like with glair & the
lumpiest, to fill the chasses with salt water or
wine, that they do not ally so well. Since they are of the same
nature & are moistened the same, they embrace each other, & hold
together one with the other.

To mold well, after having prepared your sands, mold in
a day. Slowly reheat them the next day, then cast them
on another.




One ought to choose the one which is usually as in clods
& lumps, well deep in the earth, for usually the one that
is found above has too much earth, and the deep one is
similar to rock.


I have molded with it in pure lead very neatly hot,
& I had as an example the first very neat one, but the
vinegar hardly gives it any bond, & thus it withstood only
one cast. 

