On certain jobs—as, for instance, in the case of a 6-inch silo wall—a
spade cannot very well be used, on account of the narrowness of the
concrete section. In this event, use for surfacing, a thin wooden
paddle, made from a board 1 inch by 4 inches, and gradually sharpened
to a chisel edge at the end. The sharpening should be on one side only,
and in using this paddle place the flat side against the Form, as shown
in illustration.
When the mixture is a _dry_ one, great care must be used in this
“spading” or surfacing, in order to obtain uniform results, but in
the case of a _wet_ mixture, spading is only required as an added
precaution against the possibility of voids in the face of the work,
and in many cases it is not necessary at all.