Mixing your own darkroom chemicals - the starter kit

[khh]

I've seen many posts here about how people should mix their own chemicals, and there are plenty of resources for formulas, but I haven't seen anyone put together a basic getting started list with a list of the basic ingredients you should have at hand and the most popular formulas. I've tried putting together such a list, but I am pretty new at this, so points, help and tips are very much appreciated.

General advice​

When mixing a formula, you should generally start with the water. Add ingredients one at a time in the order given in the formula, making sure each chemical has fully dissolved before you add the next one. Glass, plastic and stainless steel are generally appropriate as stir-rods, but beware that cheap steel might tarnish. Some formulas are sensitive to iron ions, avoid using steel when mixing these. Formulas might have special instructions deviating from the general advice, Make sure you wear your PPE, gloves, eye-protection and in some cases a respirator. Many photo chemicals are toxic and/or mutagenic, you need dedicated equipment not used for other purposes.

Several chemicals are available with different amounts of water molecules (H2O) incorporated in the crystal structure. These are almost always interchangeable, certainly in aqueous solutions (i.e. solutions containing water), though you have to adjust the amount. If there's no water it's termed "anhydrous", otherwise it'll be termed "monohydrate", "dihydrate", "trihydrate", etc. indicating how much water is incorporated. If it's not stated on the packaging, the easiest way to determine what compound you have is generally to google the CAS-number, which uniquely identifies the compound. In formula form the number of water molecules per unit cell is spelled out explicitly, so sodium sulfite heptahydrate is Na2SO3 · 7H2O)

One of the biggest advantages of mixing your own chemistry is that you can mix just the amount you need. To scale a formula up or down to the amount you need, simply scale all ingredients by the same factor. E.g. to convert from a formula to make a liter to make 200 ml, you'd divide all ingredients by 5.

Good places to look for formulas are The Darkroom Cookbook, Digital Truth and - of course - this forum.

Equipment​

You will need some basic equipment to get started.

• Scale(s) that can measure 0 - 10 g at 0.1 g accuracy, and 10 - 250 g at 1 g accuracy.
• Weigh ship to weigh chemicals in (can be folded paper or coffee filters)
• Container to mix chemistry in
• Stir rod

Film developers​

Developers generally consists of one or two developing agents (metol, hydroquinone, ascorbic acid, pyrogalol, etc) plus support chemicals that regulate activity, pH and scavenge oxygen. Below are some common developers you can mix yourself.

D23 (1 l)​

Ingredient	Amount
Water	900 ml
Metol (Kodak calls it "Elon")	7.5 g
Sodium Sulfite, anhydrous (Na2SO3)	100 g
Cold water to make 1000 ml

D76 (1 l)​

Ingredient	Amount
Water at ~50 °C (~125 °F)	750 ml
Metol	2 g
Hydroquinone	5 g
Sodium Sulfite, anhydrous (Na2SO3)	100 g
Borax (Na2B4O7 · 10H2O)	2 g
Cold water to make 1000 ml

Caffenol (1 l)​

Ingredient	Amount
Water	900 ml
Sodium carbonate, anhydrous (Na2CO3)	24 g
Ascorbic acid	20 g
Instant coffee	45 g
Cold water to make 1000 ml

(Personally I'm not a fan of Caffenol, as I think it's a waste of coffee. I prefer PC-TEA or Mytol for self mixed ascorbic acid developers, but caffenol is much more common)

510 Pyro (100 ml)​

Ingredient	Amount
TEA (triethanolamine)	75 ml
Ascorbic acid	5 g
Pyrogallol	10 g
Phenidone	0.375 g
TEA to make 100 ml

NB: Pyrogallol is fairly nasty, mix in a well ventilated area and consider using a respirator.

Paper developers​

Paper developers are very similar to film developers, but are generally higher contrast.

D72 (1 l)​

Ingredient	Amount
Water at ~50 °C (~125 °F)	500 ml
Metol	3.1 g
Sodium sulfite, anhydrous	45 g
Hydroquinone	12 g
Sodium carbonate, anhydrous	67.5 g
Potassium bromide	1.9 g
Cold water to make 1000 ml

Dektol-like, neutral paper developer.

Ansco 130​

Ingredients	Amount
Water at ~50 °C (~125 °F)	750 ml
Metol	2.2 g
Sodium sulfite, anhydrous	50 g
Hydroquinone	11 g
Sodium carbonate, anhydrous	65 g
Potassium bromide	5.5 g
Glycin	11 g
Cold water to make 1000 ml

General purpose paper developer, reportedly gives very good blacks.

Miscellaneous​

Hypo clear/wash aid (1 l)​

Ingredient	Amount
Water	750 ml
Sodium sulfite, anhydrous	100 g
Sodium metabisulfite (Na2S2O5)	25 g
Cold water to make 1000 ml

Dilute stock 1+4 to get working solution

Starting chemicals​

Here's a list of chemicals to buy to get started, which will allow you to mix the most common stuff, along with some suggested amounts. Supplement with the ingredients for the specific formula you're interested in.

• Metol, 20 - 50g
• Hydroquinone, 20 - 50g
• Ascorbic acid, 50 - 100g
• Sodium sulfite, 500 g - 1 kg
• Sodium metabisulfite, 100 - 250 g
• Borax, 10 - 50 g
• Sodium carbonate, 50 - 200g
• Potassium bromide, 10 - 30g
• Sodium thiosulfate, 500 g - 1 kg
• Acetic acid

 

[Nicholas Lindan]

My list would scratch the Ascorbic Acid and Borax and add Boric Acid and Sodium Metaborate.

Boric Acid & S. Metaborate are used as a pH buffer that also replaces the Borax when making D-76. The Borax-only formula exhibits activity shift in the first week after mixing.

The only use of Ascorbic Acid is when making Caffenol and its relatives. Ascorbic acid is a good addition to the kitchen, however. Other dual use chemicals are S. Bicarbonate (which can be heated in the oven to make S. Carbonate), pickling salt (pure unadulterated salt that will cake on you), Alum for hardening fixers (also used in pickling) and the aforementioned S. Carbonate (washing soda), Borax (another laundry additive), and Boric Acid (for getting rid of ants when made into a slurry with corn starch and sugar - very effective slow poison that kills the queen).

 

[khh]

My list would scratch the Ascorbic Acid and Borax and add Boric Acid and Sodium Metaborate.

Boric Acid & S. Metaborate are used as a pH buffer that also replaces the Borax when making D-76. The Borax-only formula exhibits activity shift in the first week after mixing.

That's exactly the sort of feedback I'm looking for. What are the amounts for D76 made with boric acid and sodium metaborate?

 

[Anon Ymous]

The only use of Ascorbic Acid is when making Caffenol and its relatives.

Well, the OP included 510 pyro in the post, which contains ascorbic acid. Apart from that, it can be used to mix Xtol clones and other developers.

@khh I'd buy no less than 1kg for chemicals like sulfite, carbonate and thiosulfate. I'd also favour no less than 100g of hydroquinone. Certainly more than the metol I'd buy.

 

[Alan Johnson]

I would get a copy of The Film Developing Cookbook by Anchell and Troop to provide a clear explanation of the differences between the various developers and what type(s) of film each is best suited to. Maybe then get a few chemicals. Get a proprietary fixer (contains ammonium thiosulfate) rather than the much slower acting sodium thiosufate. A water stop bath may suffice. Btw, your list omits phenidone.

 

[koraks]

The only use of Ascorbic Acid is when making Caffenol and its relatives.

No, that's not right. XTOL clones can also be made with ascorbic acid (forming ascorbate in situ, just like in caffenol) as well as some of the more novel DIY paper developers or D76-derivatives, and probably some more I'm currently forgetting.

With lists like these there's always the question what should or shouldn't be included. It's an endless discussion. Some would argue that amidol should definitely be on the list, others would absolutely demand pyrocatechol to be included and yet others would insist that hydroquinone taken off of it...

I think it's a nice starting point and moreover a great effort to try and create a sort of skeleton setup for people getting into mixing their own B&W chemistry. Well done @khh!

 

[Alessandro Serrao]

Starting chemicals​

Here's a list of chemicals to buy to get started, which will allow you to mix the most common stuff, along with some suggested amounts. Supplement with the ingredients for the specific formula you're interested in.

• Metol, 20 - 50g
• Hydroquinone, 20 - 50g
• Ascorbic acid, 50 - 100g
• Sodium sulfite, 500 g - 1 kg
• Sodium metabisulfite, 100 - 250 g
• Borax, 10 - 50 g
• Sodium carbonate, 50 - 200g
• Potassium bromide, 10 - 30g
• Sodium thiosulfate, 500 g - 1 kg
• Acetic acid

I would add:
boric acid
sodium hexametaphosphate, or EDTA, or dissolvine and the likes if you plan to use tap water

 

[Melvin J Bramley]

For Hypo clearing agent use 1 teaspoon of baking soda per 1 litre of water.

Simple yes?

 

[MattKing]

For Hypo clearing agent use 1 teaspoon of baking soda per 1 litre of water.

Simple yes?

I don't think so.
Hypo Clearing Agent:

Note that the main ingredient is Sodium Sulfite.

Baking Soda is something entirely different: Sodium bicarbonate

 

[RalphLambrecht]

happy to help. The attached pdf has exactly that: a basic list of ingredients and the first basic formulae. Enjoy

 

[koraks]

The attached pdf has exactly that

Very convenient - thanks for posting this @RalphLambrecht !

For Hypo clearing agent use 1 teaspoon of baking soda per 1 litre of water.

I think sulfite does a better (quicker) job, followed at some distance by carbonates. Between carbonates, I expect actual carbonate (sodium/potassium carbonate) to be quicker/more effective than sodium bicarbonate due to the higher pH of the former, causing more swelling of the emulsion and hence more effective washing. When I need to clear something from an emulsion relatively quickly, I generally just use a little sodium carbonate as it's cheap, easily available and gets the job done quite well.
I've read some testing data about this years ago somewhere; maybe it can still be found with Google.

 

[snusmumriken]

To the essential equipment list, I would add a 1 litre measuring cylinder, a thermometer, bottles (preferably glass) and a photographic filter funnel such as the Paterson. The stirring rod is preferably one with a flattened end to stomp on big crystals that are slow to dissolve!

I don’t want to complicate a ‘starter’ thread but before hunting for metaborate read this earlier thread first.

 

[Ian Grant]

For Hypo clearing agent use 1 teaspoon of baking soda per 1 litre of water.

Simple yes?

That works, see below.

I don't think so.
Hypo Clearing Agent:
View attachment 384409
Note that the main ingredient is Sodium Sulfite.

Baking Soda is something entirely different: Sodium bicarbonate

Matt, a correction: A 1% solution of Sodium Carbonate is recommended as an interim bath after fixing, and before washing for Fibre based papers in the Aga "The Black & White Manual" on page 70.

Sodium Bicarbonate will work as well as Sodium Carbonate, alternatives are Citrates and Sulphates, according to L.F.A. Mason, Photographic Processing Cemistry. .

I think it's more important when using Carbonate that the print goes from the fixer to the Interim bath. The "Fixing" process is a complex sequence with many equilibrium balances, and it's important to break weak bonding of residual Thiosulphate with the Gelati and paper fibres in the base.

Ian

 

[jk0592]

Would a magnetic stirrer be useful ?

 

[snusmumriken]

Would a magnetic stirrer be useful ?

Perhaps, but not essential: I’ve managed without one all my life.

 

[Nicholas Lindan]

As I recall S. Carbonate was discredited at some point as a hypo clearing agent (HCA). It may have been recredited at some other point. I don't know that there is any advantage to it. Kodak's HCA is pH buffered to the 'isoelectric point' of gelatin https://en.wikipedia.org/wiki/Isoelectric_point which is claimed to aid in getting the gelatin to release silver/sulfur compounds that got stuck in there during the fixing process.

I got so pissed off at Agfa with the bronzing problems of it's RC paper that the hairs on the back of my neck stand up whenever I see orange.

 

[Ian Grant]

As I recall S. Carbonate was discredited at some point as a hypo clearing agent (HCA). It may have been recredited at some other point.

In over 50 years the only HCA I've seen discredited by all companies has been Hydrogen Peroxide. That was recommended by Kodak and others when I first became seriously interested in photography. I used it while at school.

Dr G.I.P. Levenson was Kodak Research Harrow's expert on wash aids (HCA), and was the editor of L.F.A. Mason's book, so joint expertise from both Ilford & Kodak. I think they were both head of their respective research departments at the time.

HCA is pH buffered to the 'isoelectric point' of gelatin https://en.wikipedia.org/wiki/Isoelectric_point which is claimed to aid in getting the gelatin to release silver/sulfur compounds that got stuck in there during the fixing process.

It's not typically an issue with RC paper, it's Fibre based where the intermediary silver thiosulphate complexes can bind to the cellulose, the higher the Silver content the greater the issue. This is why films & RC paper can be fixed without issues with a much higher silver content in the fixer, compared to FB papers, with short wash times and no archival problems.

Ian

 

[Melvin J Bramley]

This will bring the chemists out in force.

Hypo clearing [Archive] - Film and Darkroom User

[Archive] Hypo clearing Monochrome printing techniques

www.film-and-darkroom-user.org.uk

FWIW, many years ago an Ilford rep suggested sea/salt water to clear hypo.

 

[RalphLambrecht]

Would a magnetic stirrer be useful?

I bought one used for very little money with a heating plate. I wouldn't want to miss it. I add the chemicals to the water, set the temp to about 50D and the stirring speed to low. Then, let it run until all chemicals are dissolved. Extremely convenient and fun to watch.

 

[ags2mikon]

I started mixing my own solutions from formulas back in the 1980's with D-72 and HCA. Every year my "chemistry set" just gets bigger and bigger. During the last few years with all of the shortages and shutdowns it has been a godsend. As to the magnetic stirrer, I have one in both darkrooms and I find them worth the investment. And as Ralph said "fun to watch".

 

[Milpool]

This will bring the chemists out in force.

Hypo clearing [Archive] - Film and Darkroom User

[Archive] Hypo clearing Monochrome printing techniques

www.film-and-darkroom-user.org.uk

FWIW, many years ago an Ilford rep suggested sea/salt water to clear hypo.

The process is ion exchange. Sulfite is most effective/efficient.

 

[MattKing]

This will bring the chemists out in force.

Hypo clearing [Archive] - Film and Darkroom User

[Archive] Hypo clearing Monochrome printing techniques

www.film-and-darkroom-user.org.uk

FWIW, many years ago an Ilford rep suggested sea/salt water to clear hypo.

It will actually serve to stabilize the print, permitting fairly long term storage before finally using proper fixer.

 

[Mick Fagan]

Would a magnetic stirrer be useful ?

In a word, yes!

I've been mixing powdered chemistry for over 60 years, recently I looked into purchasing one, this thread is my story of what I was looking for, what it cost and how it works.

Now that I've had it for some time, I cannot see myself ever going back to hand stirring; unless I was really forced too.

Magnetic Stirrer. Straight, or One With Heating to a Specific Temperature Feature?

Mick you mentioned the capability of inducing a vortex in 2000 ml of fluid. A vortex is the last thing you need when mixing developers. That fascinating, spiral depression in the middle of the fluid is introducing oxygen into your liquid developer all the time. Better to have the fluid...

www.photrio.com

 

[Keith Tapscott.]

Black and white developer recipes | spaq.in

The infromation is slowly disappearing from the net. The other day I realized I cannot find the recipe for D-76d I've been using! So there's…

spaq.in

Here are a variety of fine grain film developers for the OP to consider.

 

[Ian Grant]

Black and white developer recipes | spaq.in

The infromation is slowly disappearing from the net. The other day I realized I cannot find the recipe for D-76d I've been using! So there's…

spaq.in

Here are a variety of fine grain film developers for the OP to consider.

Interesting, that's all from this page on my website.

Ian