The dimensions are for a tank and reel to accommodate 400 feet of single-eight film. Or 200 feet of double-eight
or sixteen mm. The tank takes one and a-half gallons of solution. For shorter lengths the tank size can be
reduced to take less liquid.
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The tank is made from a five-gallon oil can. A new, unused one is inexpensive. (Oil would probably be very
difficult to remove completely). One side of the can illustrated measures 9x12 inches.
Two pieces of of 3/4" five-ply wood measuring 9x12 inches are beveled on the long side to fit the rounded
corners inside the can. On the inside (unbeveled) surface of these three pieces mark out a strip one-inch wide
running down the center the long way. On each side of this strip fasten 3/8" square strips 12" long, spaced 3/8"
apart. These strips act as guides and spacers for removable panels. |
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The two five-ply sides are joined by a 7/8" thick piece of white pine which has been rounded on each end. This
piece measures 7"x7" and holds the sides, in the form of an "H". Long screws through the sides into the center
piece and a waterproof glue of the casein type will make a solid joint.
Removable panels are cut from 1/4" plywood which will slide freely in the channels between the 3/8" strips. These
are of varying lengths. The two next to the center piece are 8" long, the next pair 9", the next 10", and so on,
each pair an inch longer than the preceding pair. When inserted into the reel, each set is 1/2 inch longer at each
end than the set before it. These staggered panels prevent the successive layers of film from touching each other
by holding them on different levels.
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Place all panels in position and mark the location of each. Staples set in the channels prevent their sliding clear
through at one end, and the other end is secured by sprig catches made from bent strips of 1/4" spring steel
fastened in the channels with staples.
A row of small brads is put down ech end of the panel and on the ends of the center piece. If you process single
eight these will be 3/8" apart; but for double eight or 16 mm. film they will be 1 1/4" apart.
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Since it is possible to develop the loaded reel in the open tank in a darkroom, directions for for loading the reel
will be given before describing the construction of a lightproof cover that permits daylight processing.
The reel is placed on a support allowing it to be turned end for end while loading. Short lengths of dowel
may be set into holes drilled in the side pieces and the reel mounted on a stand. The dowels are removed before
immersion in the tank. |
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The sliding panels are removed and the the film thumbtacked to the centerpiece. As the reel is revolved,
the film is wound between the brads on the centerpiece until it is full.
Then the two smallest panels are slid into their channels until they come to rest on the staples at one end
and have gone past the spring catch at the other. The film is then wound around these panels, encircling the
loaded centerpiece but not touching it. When this set of panels has been wound with film, the next larger set
is inserted and loaded, etc., until the film or the panels are used up.
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In effect, the film has been wound on a succession of drums, one within the other, each one being larger
than the one before it. The film may now be processed in a darkroom by lowering it into the tank.
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A lightproof cover is constructed as follows: Cut a piece of 1/4" plywood one inch larger all around than the tank
opening. Cut a three inch hole in the center. A two inch deep frame is built in this piece. One inch inside
this frame another frame is placed so that it comes inside the tank when the cover is placed in position,
forming a light trap.
Two pieces of 1/2x2" wood, four inches long, are fastened on either side of the hole. At right angles and 1/2"
from the ends of the first two pieces fasten two more the same size. It is possible that these two sets of
baffles will block any light entering the pouring hole, but for safety's sake, another pair, long enough to overlap
the ends of the second set, are placed parallel to the first set. Fig. 15 clearly shows the internal construction
of the light trap.
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After painting all the surfaces of the labyrinth thus formed with black asphaltum paint a piece of plywood
slightly smaller than the tank is fastened to the edges of the baffles.
With the cover in place solutions poured in the hole land on the plywood, run between the first pair of baffles
to the second pair, past these to the third pair and across the plywood to fall off the edge into the tank.
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For draining the tank a short section of 3/4" brass nipple is soldered in a hole at the lower edge of the tank
and fitted with a two-foot length of hose to provide rapid drainage. If desired the end may be corked, but no
valve is necessary since the solutions cannot run out as long as the end of the of the hose is held higher than
the top of the tank. If the hose is kept curved or bent, no light can enter.
The entire reel, tank and cover should be given several coats of acid resistant paint such as Probus, Eastman's
Kodacoat or other black asphatum paint. Let the paint set hard , not merely dry, before using. The strips
forming the channel to hold the panels are slightly less than 1/4" thick. This allows for several coats of paint,
which are thicker than might be imagined. So don't try to make too close a fit in the beginning.
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The loading of the reel, even in total darkness, will be found to be quite simple, if the panels are laid out in
the proper order beforehand and the necessary thumb tacks and reels of film are placed where they can be found.
This permits the development of even the fast panchromatic cine films, formerly considered a hardship to the most
experienced worker.
Once the lid is on, it's merely a question of pouring and draining all done in daylight.
