FYI, It is VERY expensive to import things to Barbados so I have mixed most of
my own for a while. What was really irritating was trying to buy ammonium
thiosulfate archival fixer and import it. I decided to research it and found
that all you need is sodium thiosulfate and ammonium chloride or ammonium
sulfate (& of course a little sodium sulfite) to make F9 fixer. Nearly
impossible to find ammonium chloride here BUT I could get large quantities of
thiosulfate and ammonium sulfate at reasonable prices locally. An added
benefit of using the sulfate is that there are many formulae for "tropical high
temperature" fixers using "glauber salts", i.e., sodium sulfate because of its
very mild emulsion hardening properties without the usual acid hardeners found
in other fixer formulae. I adjust the pH just a "lillabit" above 7 to keep it
alkaline and have had excellent results with both film and paper. And, yes,
the papers tone just fine...
-----Original Message-----
From: pure-silver-bounce@xxxxxxxxxxxxx
[mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of `Richard Knoppow
Sent: Monday, March 29, 2021 6:41 PM
To: pure-silver@xxxxxxxxxxxxx
Subject: [pure-silver] Re: New Dektol, dark brown
This is what I meant by looking out for recommended things to
have. You really need very little. You need:
The chemicals, make a list from the formulas you decide to try.
Many will be duplicated, i.e., the same materials will make film
developers and paper developers and you need only one fixer.
You must be able to measure out the amounts. That means a scale
capable of indicating grams and a graduate capable of indicating
milliliters. The required accuracy is minimal, kitchen measures
are adequate.
You need a container to mix in, plastic kitchen bowls will do.
You need something to handle the chemicals, plastic spoons
are fine and those little paper cups for making muffins are good
throw away containers for measured out powder.
A plastic spoon for stirring.
A couple of funnels of different sizes. Get the funnels at
the grocery store or 99c store, the ones at the darkroom supply
are the same but double the price.
Bottles to hold the mixed solutions. While brown bottles are
recommended they are not necessary. If they solutions are going
to be stored in the dark, like a closed cabinet, colored bottle
are not necessary. Glass is best but some plastics do not leak
air readily, a google search will show which. Wide mouth bottles
are best for convenience.
A thermometer, the temperature of the water is important but
the thermometer does not have to be super accurate. It is
possible to get the water too hot because it will cause
decomposition of some salts (sulfite in particular) but its not
very critical. Hot water is rcommended because the rate of
solution is greater as the heat is increased. Kodak recomends
125F for most formulas.
That is about all you need.
The method of mixing is simple but there are some tricks.
First of all stirring in general should not be violent (there are
exceptions). If you beat the water you get air in it which can
cause oxidation. The water has to be stirred enough to keep
particles in suspension until they dissolve. Just keep stirring.
Sometimes there will be a residue but it often resolves after
standing overnight.
Mix in the order given. For instance, Metol (AKA Elon) does
not dissolve well in a concentrated solution of sulfite so it is
dissolved first. While the sulfite may remove some oxygen from
the water the metol does the same thing and very little of it is
used up.
Add each chemical after the last is dissolved. Add them
relatively slowly, don't just dump them in.
The water will cool as you mix so the rate of solution may
slow down a bit. If you have the means you can heat the water but
its not really necessary.
For all but a few solutions (like some Amidol developers) the
mixed solutions should be left overnight to cool and fully
dissolve. Just make sure the bottle are sealed.
Label everything carefully. Write the date that the solution
was mixed on the bottle. (Should do this even when mixing
packaged chemicals).
When you are finished wash everything right away and put it
away.
A note: if you mix fixer the traditional fixing bath uses
sodium thiosulfate in crystalline form. It is, lost a word but it
means it absorbs heat as it goes into solution, so the water
should be quite hot, as much as 160F. In fact, dissolving hypo
was a laboratory trick to get a cold solution to cool other
things. Hypo is also available in desiccated form. In fact, most
packaged hypo is dessicated because it weighs less. This does not
absorb heat and can be mixed in warm water. Ammonium thiosusfate,
for rapid fixer, is usually supplied as a liquid concentrate so
can be diluted in cold water.
Because modern emulsions, both film and paper, are hardened
more in manufacture than those of the past hardening fixing bath
is not really necessary although there are reasons it should
still be acidic. you can just leave the alum out of the fixer and
reduce the amount of acid. There are formulas for non-hardening
fixing baths. Actually, thiosulfate and sulfite alone will work
quite well.
Distilled water is not necessary but clean water will prevent
material from being deposited on the emulsion. You can boil water
for a few minutes and let it stand and cool to drive out air and
some other materials but its usually not necessary. Coffee
filters work OK for getting rid of particulate matter. This
applies to packaged chemicals too.
While Lawrence Cuff disagrees with me about the differences
in developers a comparison of the ingredients of working
solutions will show there are really only a couple of basic
formulas for paper and for film differing mainly in activity.
Every manufacturer of paper had a formula similar to D-72 and
most a less active formula similar to F-52. Agfa/Ansco 130 is
unique because it has a third developing agent in it, Glycin.
Without the glycin, its very similar to D=72. Most of these
formulas were standardized decades ago and most work. The
differences in similar published formulas suggests that the
precision of measurement needed is not very great.
For the most part fumes are not much of a problem but can be
when mixing solutions like fixer that have both acid and sulfite
in them. They can release sulfur dioxide gas, a sharp smelling
gas that is very irritating to the bronchia. Good ventilation is
suggested and there are fixer formulas intended to minimize the
odor and output of gas. The other gas is hydrogen sulfide. This
is encountered mostly with toning baths. Hydrogen sulfide is the
odor of rotten eggs and solutions that emit it should be used out
of doors preferably. It is mostly encountered in "sepia" toners.
It will also poison photographic emulsions so unexposed film and
paper should never be exposed to it.
Go over the mixing process in your mind and imagine doing it.
That will bring to mind anything you need.
On 3/29/2021 2:06 PM, Janet Gable Cull wrote:
Sounds interesting but I'm not gonna start mixing my own
chemicals. The list of "only things" I need talks me right out
of it.
