AGFA's Rodinal developer was patented in 1891 by Momme Andersen, its formula being the oldest formulas still being produced. With the closure of AGFA and the termination of the patent right, several "Rodinal-like" developers started to be produced by various companies under other names, maintaining their global characteristics, which made it famous: good brightness, contrast and sharpness.
The essential compounds of its composition were the paraminophenol developing agent, the potassium metabisulfite (as preservative) and the base or reaction accelerator, sodium hydroxide.
The knowledge that acetaminophen (acetaminophen) in contact with caustic soda generates an aminophenol compound has led some amateurs of the alternative methods to roll up their sleeves and start the home production of a paracetamol-based "Rodinal".
That's what I did too, my Parodinal!! :-)
I bought a box of 1g paracetamol tablets in a pharmacy. With the kitchen shredder, I triturated 15 of the 16 tablets (one stayed for the headaches if I could not get some results:-)). I dissolved the powder obtained in 150 ml of warm water. After thoroughly disintegrating, I added 50 g of Sodium Sulfite and stirred until complete dissolution of the powder. Finally (and with the use of gloves and precautions), I added 20 g of sodium hydroxide (caustic soda). The temperature of the solution rose sharply. I completed the solution with water at room temperature until 250 ml of solution was obtained.
I kept it in a dark, well-closed bottle and placed it in a light-free place. I did not find data about the validity of the solution achieved and saved this way.
This solution is used in exactly the same way as the Rodinal, in both dilutions and development times and temperatures, for each film in question, according to the Digitaltruth website. When the working solution is formed, it must be used within the next 30 minutes and can not be reused, as it is stated! :-)
My first development whit my Parodinal
...and C41 film in black & white chemistry homemade ;-)
silver print-
F70
kodak color plus (exp7/2011) Parodinal (homemade Rodinal whit paracetamol pills) 1:50 15'-20º Homemade fixer Enlarger (Durst M670 BW - f 5,6) Ilford multigrade MG IV 20,3 cm x25,1 cm Ilford multigrade developer rapid fixer