Stock Solutions & Capacities

One of the regular PhDs, “Eli,” writes:

“I purchased 5 gallons of Dektol developer, but it didn’t come with clear directions. How much do I mix for a use of a day? I also have Ilford rapid fixer, 1 liter. I need help/directions for diluting both. I would appreciate your help/input. Thanks!

PS. Where/how can I dispose these chemicals?”

Well, Eli, the standard dilution for Dektol is one part stock solution to two parts water to make a working solution, e.g. 10 ounces Dektol and 20 ounces (tap) water. That can be altered by you in order to affect contrast in the print: 1+4, for example, might help a negative that needs a (mythical) 3 ¼ filter. This developer throws a little sludge in the tray with use, and it’s no problem. The working solution does not last overnight for a second session.

Mix the powder in about 4/5 the eventual volume with around 100 F. water, and finishing the correct measurement with cool water. The stock solution keeps best in brown glass bottles, or opaque plastic away from the light. Kodak’s standard statement regarding storage of liquid developer concentrates is that they keep reliably for six months in full closed containers, and two months in partially-filled containers.

Rapid fixer is commonly diluted 1+7 in room temperature tap water for fixing RC paper. For a long time, I’ve been diluting the Kodak Rapid Fixer in Barrington Huge School darkroom at the stronger 1+3 dilution for a variety of reasons (occasional fiber paper short times to match RC; exhaustion insurance; unreliable fixing habits endemic to adolescence). Count your prints and test strips to ensure good fixing and to avoid overuse of the batch; I recommend 40-50 8x10s per liter for your darkroom (see to know why). I save the used fixer for regular trips to the IEPA drop-off in Naperville: