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Repairing cast things



It happens often that what you have cast makes fins, either through
fault in the mold, or from the cast, or from the metal.
The fault in the mold comes from plaster, which is not
hard & strong and does not withstand fire (which is corrected by
mixing it with crocum). Usually as well, if there is an
imperfection, it is from the cast. If there is also too much tin,
in a moderately thick thing, it does not come out well, because
tin cast thickly retracts & becomes porous. Also, things
molded hollow are fanciful to cast. If, therefore, some flaw should
happen, take a leather cushionet, full of fine sand,
& having placed it on the bequet of the
goldsmith’s table, where one files, place
your work on it & secure it with a rope, which passes
under your foot. The sand in the bag
obeys & arranges itself by and by, thick on one side & thin on
the other. Then, forthwith, with a burin, make & trace
roughly the fine lines, which were omitted or which are not apparent
enough, either with a file or a chaple remove
the fins. And if there is some flaw in the substance, which left some
pit or something too hollow, rescrape this with a burin, and
notch around the edge, then imprint this with some wax. And place
the imprint on a delicate plate of lead, & mark
thusly the appropriate measure of lead or of the alloy similar to
your substance, then place the piece of the notched thing & attach
it well with some latten wire, then rub the edge with
rosin if it is tin or lead & place all around
some small thin pieces of solder or tin or other things,
then with a hot iron or in the fire of the
forge, solder, and next repair this with the above-said
tools, & with the appropriate small chisels.



For gold & small work, one needs to ciment it on a ball of
lead, which will be placed on the cushionet & will
be held thusly with the rope.

