A pocket is provided for the liquid developer in one end of the
tray when it
[Illustration: Developing Tray with Glass Bottom]
is turned up in a vertical position. A tray for developing 5 by
7-in. plates should be made 8 in. square inside. The side pieces
with the grooves for the glass are shown in Fig. 1. Two of each of
these pieces are made with mitered ends. The short groove shown in
the top piece of the illustration is for inserting the plate
covering on the pocket end of the tray.
Two blocks, one-half the length of the side pieces, are put in
between the glass plates to hold the plate being developed from
dropping down when the tray is tipped up in a vertical position.
The glass bottom of the tray is 8-1/2 in. square, which allows 1/4
in. on all edges to set in the grooves of the side pieces. The
wood pieces should be well soaked in hot paraffin, and the mitered
corners well glued and nailed.
--Contributed by J.A. Simonis, Fostoria, Ohio.
** Iron Putty [269]
A good filler used as a putty on iron castings may be made as
follows: Take, by weight, 3 parts of stiff keg lead, 5 parts of
black filler, 2 parts of whiting, 5 parts of pulverized silica and
make into a paste with a mixture of one part each of coach japan,
rubbing varnish and turpentine.
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