in diameter.
Now comes the critical part of the molding operation--that of
lifting the cope from the drag. It is here that the amateur often
becomes discouraged, as the sand is liable to fall out of the cope
and spoil the mold; but with a little practice and patience the
molder can lift the cope every time without breaking it, as shown
at G.
The next operation is that of cutting the gate, which carries the
molten metal from the sprue to the opening left by the pattern.
This is done with a spoon, a channel being cut about 3/4 in. wide
and about 1/4 in. deep. The pattern is then drawn from the mold,
as shown at H, by driving a sharp pointed steel rod into the
pattern and lifting it from the sand. When a metal pattern is used
a thread rod is used, which is screwed into a tapped hole in the
pattern. Before drawing it is well to tap the drawing-rod lightly
with another and larger rod, striking it in all directions and
thus loosening the sand slightly from the pattern. Some molders
tap the pattern gently when withdrawing, as shown at H, in order
to loosen any sand which has a tendency to stick.
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