Bulk Chemicals for the Darkroom

Lloyd Erlick.
January, 28 1998

Lately I've been trying to rectify a personality defect. I have been dependent on prepackaged darkroom chemicals for many years, and it’s time to break the habit.

Most people who do this are in it for the money, and I'm no exception. But there are certainly many interesting darkroom formulas I’d like to try, and many interesting darkroom chemicals never found in prepackaged products.

First, the money. Two of the most commonly used darkroom chemicals are sodium sulfite and sodium thiosulfate. At the camera store, thiosulfate is absent. Sulfite is often available in one or two pound containers, usually priced around seven to ten Canadian dollars per pound. Today, one pound bottles of Kodak sodium sulfite are selling for C$8.95 at West Camera, my preferred retailer here in Toronto. I used my first container, the two-pounder from Edwal (fourteen bucks worth in Otnorot, January 1998!) quickly enough that I wasn’t eager to do it again.

Years of self abuse in the fixer department are part of my motivation, too. A five liter container of rapid fix concentrate runs in the sixteen to twenty dollar range. Signal sells it in 5 US gallon cubitainers for about forty five Canadian dollars. It has a huge capacity, but I can never exhaust it before it’s too old. My throughput is too small. I would be satisfied with the speed of action of old fashioned regular fix.

So I had a quest! Where to get the requisite bulk quantities of chemicals at bulk prices?

Here in Toronto, (affectionately known as Otnorot), there are many small photo processing companies. One-hour labs. We all know they’re cheapskates, so I surmised they would get their chemistry at the cheapest source. I snooped around, and hung out in back alleys where the delivery trucks parked. I came up with Signal, Inc. I checked the yellow pages under ‘chemicals’ and they were not listed. Their name does not contain the word chemical. Interesting. A phone call led me to a very friendly and helpful chemist named Stan who subtly probed me to see if he would feel right about selling this stuff to me. And the trip to their warehouse …

The cheapest source of chemicals must be located near a port or rail link. I found these guys near the docks in downtown Otnorot. The outside of the building revealed nothing about chemicals or anything else except the street number. Inside they had gigantic quantities of bags and plastic containers of various raw materials. And an impressive number of seriously large tanks, one of which released five US gallons of glacial acetic acid into a cubitainer for me (C$73.50 in Jan 1998.)

Sodium sulfite anhydrous came in 25 kilogram plastic bags from Germany. It’s nice to know I'm not so old and feeble I can’t lift fifty five pounds. Price: C$1.21 per pound (C$66.55 per bag).

Among many other uses, sodium sulfite is the primary ingredient of hypo clearing agent. Many darkroom people use it in place of packaged hypo clear. Twenty grams per liter of working solution - pretty cheap at a dollar a pound. Prepackaged hypo clear has a buffer and perhaps something to give it a shelf life in the package. But if it’s used one-shot, plain sulfite will suffice. No more overpriced packages of Kodak Hypo Clearing Agent for me (in Otnorot, about C$6.00 for the one gallon concentrate size that dilutes to 19 liters working solution. I use three liters or more every time I make prints. The working solution does not keep well.)

Sodium thiosulfate anhydrous of fixer fame is a well known darkroom material, too. Signal sold it to me in a one hundred pound bag for C$126.00. I'm planning to stop using ‘rapid’ fixer for making fiber based prints. Mostly it’s the smell I don't like, but I also have become a little mistrustful of the short fixing times claimed for it when used on paper at the higher ‘film’ concentration. Some papers, such as Kodak Elite, are known to require a longer time, even in a so-called rapid fix. I know sooner or later I will suffer for relying on it, so I'm dropping back to the old tried and true fix. Ansel Adams in "The Print" describes Kodak F6, a nearly odorless fixing bath. He also discusses F24, a non-hardening fix. He states that some workers believe it improves the 'color' of black and white prints. After breathing rapid fix stink for years, I’ll put up with somewhat longer fixing times.

And speaking of odor in the darkroom, a useful chemical is citric acid. It can replace acetic acid for a stop bath when dissolved in water at 15 grams per liter, and it has no powerful smell.

To find cheap sources of citric acid, look for chemical suppliers that serve the food industry. I found it close to home at C$3.05 per kilogram in 25 kg bags. Pretty clever of me after buying five gallons of acetic acid, eh? It has other uses, too, such as to replace the sodium metabisulfite in the F24 fixer formula. I've never used this fix, but it is claimed to be odorless when citric acid is used. Citric is used with Amidol developers as well.

Sodium sulfite is used in the food industry, so check these sources for this chemical too.

One of the difficulties we have once we have purchased a load of some chemical or other is - what to do with it once we have opened the package. The one hundred pound paper-and-plastic bag of hypo and the 25 kilogram plastic bag of sulfite are good examples, especially if anhydrous chemicals have been purchsed. Left exposed to normal room humidity, these materials would eventually suffer. They should be stored in air tight containers. I scavenge the large plastic pails thrown in the garbage by restaurants. They usually are in the range of 20 liters, and come in both round and square cross-sections. The square ones store more compactly, but are usually smaller than the round ones. The lids are important to find along with the pails; they are air-tight and strong enough to permit stacking the full pails. Avoid pails that have held oils or fats. Good ones to take home and scrub out (and dry!) have contained water soluble materials like muffin mix or mayonnaise. I have found that the 25 kg bags of sulfite slip right into one of these pails, bag and all. Once opened, the bag can simply be rolled shut again and sealed in the pail. The hundred pounds of hypo can be slowly and gently scooped into two or three pails. Try to avoid raising dust; do it outdoors. Never allow dust from any chemicals to be released in the environment where you make or store photographs, or where you store photographic paper or film. And never breathe the dust from any chemical, either! Even relatively innocuous chemicals like sodium sulfite and sodium thiosulfate must be treated with respect - dust in the lungs is much different from chemicals on the hands.

This might be a good place for my disclaimer: handle all chemicals with precautions appropriate to their characteristics. If you're not sure, find out before you buy! Be sure to protect your eyes! Consult the Materials Safety and Data Sheet (MSDS) for each chemical. Search the web via search-engine for "MSDS".

Many darkroom chemicals are necessary in small quantities only, and are not commonly available. Laboratory suppliers are the only sources for chemicals like potassium or sodium thiocyanate, potassium persulfate, etc. However, checking a number of sources for any given chemical will reveal a wide disparity in prices. My recent hunt for potassium thiocyanate, for example, showed prices from US$89.95 per pound, to C$74.00 per 500 grams. Americans would be well advised to check Canadian lab suppliers; the difference in the currencies is substantial these days. A good one to start with is CanadaWide Scientific Supply (1-800-267-2362.)

One of my goals in all this is to make my own gold toner. Kodak publishes a formula they call T21 Gold Toner, which uses gold chloride and silver nitrate. For these I have been stymied. Companies like Artcraft and the Photographer’s Formulary seem to offer the best prices around. I suppose they buy quantities that dwarf the ordinary user’s needs, so they can repackage and sell at an attractive price. Artcraft advertises silver nitrate at US$195.00 per pound, and they sell gold chloride for US$29.95 per gram. Small weights of very expensive chemicals can be bought from distant suppliers like these without incurring high shipping charges. But for materials that are best purchased in 25 kg to 100 pound lots, closer sources must be found as described above.

Artcraft has placed their catalog on the web, complete with prices. Check them out at Maxim Muir’s website, http://www.nfinity.com/~mdmuir/ , and while you’re there look at Maxim’s material. He is really to be commended for his effort. As a dyed in the fiber warmtone user, I plan to mix the chemicals and give his cold tone developer a try. I need to remain flexible!

The Formulary’s catalog, also complete with prices, can be seen at http://www.montana.com/formulary/index.html

Of course, once the masses of chemicals are in the darkroom (or better yet, the off-site chemical storage area), there has to be a way to measure them out in small amounts. Enter the triple beam balance! An alternative is the double-pan balance, sometimes called the Harvard Trip Balance. The market is dominated by the Ohaus Corporation, which supplies a huge range of products. I bought a plain and simple triple beam balance with tare, which means it has a provision for zeroing out the weight of a container placed on its pan. This way you can read directly the weight of the chemical you put into the container. On the Internet, check out "Scaleman" [www.scaleman.com].

A convenient way to work with commonly used chemicals like sodium sulfite is to carefully measure the weight of an easily handled volume, such as a tablespoon. I always use the same stainless steel tablespoon to measure out my sulfite. I often use 60 grams at a time, to mix three liters of two per cent sulfite. I weighed the amount of sulfite in a rounded-tablespoon, and found it was 27 grams. So two big tablespoons does it for me. The same method will work for hypo to mix batches of fix, although a larger scoop than a tablespoon might be in order.

Many other chemical suppliers have catalogs on the Internet. Using the major search engines is the best way to find them. Some do not reveal their prices, and many have very high minimum orders, some in the thousands of dollars.

Often prices of a given chemical vary from extremely high to reasonable. The likely reason is purity. Certification according to standards-setting organizations costs money. Terms like ‘reagent grade’ or 99.995% mean expensive; look for ‘technical grade’ or 97% or even food grade. Sometimes ‘photo grade’ is specified, but we all know how much a photo grade funnel costs compared to a plain old regular funnel. The darkroom worker must be suspicious at all times.

The Internet provides a wealth of material for the darkroom person. An interesting mass of material can be found at Jack's Photography & Chemistry Collection,

http://www.cybercomm.net/~spectrum/B&WFilmDeveloperFormulas.html is another interesting source of formulas and insights. John Douglas has gone to a lot of trouble to bring this to us.

Many interesting things can be learned at the following websites, although you will have to examine them carefully to see if you can do business with them:

AMERICAN CHEMICAL CORPORATION - http://www.amchemcorp.com
THE CHEMICAL INDUSTRY HOME PAGE - http://www.neis.com/chemical_companies.html
HEBELER CORPORATION - http://www.hebeler.com/
ADVANCE SCIENTIFIC & CHEMICAL, INC. - http://www.advance-scientific.com/
IC TRADING CO., INC. - http://www.ic-trading.com/
PLESCIA PHOTO'S PHOTO CHEMICAL PAGE - http://plescia.com/chemicals/
CLARKSON LAB SALES - http://www.clarksonlab.com/

Many other websites are devoted to photography, the darkroom and related matters. The Internet has added a whole new dimension of pleasure to this age old activity.

Copyright Lloyd Erlick. All rights reserved.