Page 29 - The Wellington photographic handbook

ACID FIXING BATH.*
Hypo ... ... ... ... 4 ounces 100 gramme*
Potassium Metabisulphite ... 200 grains 13
Water to ... ... ... 20 ounces 500 c.c.
If perfectly clean negatives are required, the plate should not
be exposed to anything but the red light until fixing is complete,
and the hypo bath should be fresh. Fixing should be continued
until all the white appearance has gone from the back of the
plate, and for as long again. The Acid Fixing Bath tends to give
cleaner negatives than those obtainable when a plain fixing
solution is used.
In temperate climates there is no need to use a hardening bath
with WELLINGTON Plates. If any difficulty is experienced
with frilling or blistering the reader should study the notes on pages
49 and 50, which apply equally to plates and bromide paper.
WASHING.
The simplest way to wash a single negative is to place it on
some support smaller than itself underneath the tap, and let a
gentle stream of water flow over the whole surface for half an hour.
Several negatives may be washed by hand in flat dishes in the
same space of time, by continually changing the water, draining
the plate well and rinsing the dish at each change. At least a
dozen changes should be given, allowing the plate to remain in
each for a couple of minutes. Any good automatic washer can of
course be used, and in this the plates will require very little attention.
With most waters, a fine deposit of lime accumulates on the
surface of the plate during washing. It does no harm, but is un-
sightly. It is removed by holding the plate film upwards under
the tap for a moment when washing is finished, and gently rubbing
the surface with a piece of wet cotton wool, taking care, of course,
not to scratch the tender surface of the film.
DRYING NEGATIVES.
Negatives dry quickest in a current of dry air. No attempt
should be made to dry them by heat. The grooves in most grooved
drying racks are much too close together, and at least an inch
should be left between each plate in the rack.
* Be/ore making tip any formula, read the notes on pages 125, 126 and 134.
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