Mixing Mini Batches with Kodak Dektol
Adventures with “professional” chemicals and making tiny little batches for the sake of reducing waste.
So a common delight for the home photo lab is the wonderful joy of dropping $30 AUD on a litre of Ilfords Multigrade developer, only for it to turn marathon runner wee orange within a few months of opening it, having used barely any of it.
This, is the motivation for this little exploration into powdered chemicals and mixing batches way smaller than what the manufacturer recommends.
|⚠️ Disclaimer||These shenanigans are not to manufacturer instructions, so as such your milage will likely vary. This post is straight after the first go, so there is no telling how well the powder holds up once the bag has been opened.|
So for me I rock tiny trays at the moment, only 5x7. So for that I only need an earth shattering 250mL of solution to fill the tray to operating depth.
Annoyingly 250mL is a bit of a difficult mixture so to work around this I stepped it up to 600mL of working solution for my first batch.
Now this is the fun part. 600mL of working solution, only needs 200mL of concentrate as the destructions on the pack say to make a working solution you need a 1 to 2 dilution ratio (1 part concentrate to 2 parts water).
One packet of Kodak Dektol makes up 3.8 litres (1 US Gallon) of concentrate, or a whopping 11.4 litres (3 US Gallons) of working solution. This means if we take the 551 grams of powder that’s in the bag and divide by 3.8, we get 145g (5.11ish oz) per litre (33.81 fl oz).
So to cook up a fresh batch of 200mL concentrate you need:
- 160mL of 32-38°C (or 90°F-100°F) water
- 40mL of room temperature water
- 29 grams of Kodak Dektol Powder (more on this amount later)
- 400mL of room temperature water for making up the working solution
- Some sort of plastic bottle
- Set of jeweler’s scales
- Couple of containers, jugs, cups, whatever for containing the solution whilst mixing
- Disposable plastic spoon or other mixing apparatus
- Add the powder to the 160mL of warm water. Mix until it goes clear.
- Once clear add the 40mL of water and continue mixing for a while.
- Once all mixed up and dandy, pour the 40mL into the bottle of your choice and then add the 400mL of water until the bottle is full. Note that the 29g of powder will displace an amount of water so if you’re using a 600mL water bottle (not a good idea) it will overfill if you try to add the full 400mL…
- Label the bottle with what’s in it and the date prepared and enjoy!
Now more on that powder amount. One thing I do not know is how sensitive it is to deviance from the precise measurement as you are really meant to dump the whole packet into 3 litres (~0.8 gallons) before topping it off to 3.8 litre (1 gallon).
In theory (I have not yet tested this!!!), you could round that up to 30 grams… which is easily divisible by 2 to give 15 grams, yielding a working solution of 300mL. 300mL working solution would be a lot less wasteful for me given my small trays.
My goodness the results are amazing, the contrast is superrrr punchy. It is of little wonder why people sometime use Dektol to develop film.
It seems to be of relatively low odour as well, the most stinkiest part of the process was my Ilford’s fixer which is normal considering the mixture’s age.
I am yet to determine whether Dektol is as shelf-unstable as Kodak says it is, particularly in a full sealed bottle at working concentration. Neither do I know how quickly if at all the powder will degrade once opened. The packet arrived to me expired by about 6 months but it’s strong as ever.
Overall I am extremely happy with the results that I got and definitely look forward to doing more prints once my larger trays and better infrastructure arrive.
Here is a much better quality scan.
Print run T+1 day later. Supposedly mixed chemicals are good for only 1 day, here is the print from the next day (roughly 24 hrs later). Unaccounted for variables was the chemicals were cold so likely was the cause of development being slower. No signs of yellowing yet.
Pretty much the limit of testing for now as I have other commitments. Day T+2 ½. Still developing very quickly despite being cold. Will likely pickup testing in say a week to minimise waste.
So 8 days later (final update) and the developer is seemingly no good, has started to turn slightly yellow (which stains the paper) but it is interesting to see that it probably would have lasted a few days.
One mistake that was made which may have impacted on the longevity of the working solution was I used water that was heated by the Cinestill immersion heater which aerates the water if the water level is too low so it’s likely I had heavily aerated water which Kodak specifically mentions in the mixing instructions.
On other tests, the 30g/600mL instead of 29g seems to work fine so should allow me to be efficient with my chemical usage. So far there is no signs of degradation of the powdered mixture.