Stock Solution A
Propylene/ ethylene glycol/ glycerin 75 ml
Hydroquinone 5.0 g
Phenidone 0.2 g
glycol/ glycerin to make 100 ml

Stock Solution B
Water 70 ml
Potassium carbonate 75 g
Distilled water to make 100 ml

Dilute 1+1+50 just before developing. Don't be put off by the immediate change in color. Develop 7 or 8 minutes at 70 F (21 C). An optional dilution: 2+2+50.
The B Stock can also be made as 20% sodium carbonate solution, then dilution is 1+5+50 or 2+10+50.

Some developing times, agitation for 3-5 sec @ every 3 minutes:

Свема-100, 100 ед.: 1+1+50, 13-14 мин; 200 ед.: 1+1+50, 16-17 мин
А-2Ш (Свема), 400 ед.: 1+1+50, 10 мин; 600-800 ед.: 1.5+1.5+50, 12-13 мин
Fortepan-100, 100 ед.: 1+1+50, 12-13 мин
Lucky SHD-100, 100 ед.: 1+1+50, 20-22 мин
КН-2, 1990 г., 32 ед. номин., как 100 ед.: 1.5+1.5+50, 15-16 мин

Use propylene glycol instead of the alcohol to keep phenidone. Rumors that there is no way to keep phenidone in solution are greatly exaggerated. Heat the glycol or you will have to wait a week or so for the phenidone to dissolve. The amount of Phenidone is not critical - you can measure it with a teaspoon. Too much is better than too little. 1/8 teaspoon is approximately = 0.25 grams.

The PQ-Glycol would look more like the PC-Glycol (non-staining) if you added a gram/L or so of sulfite to the working solution. Sulfite is necessary to the superadditivity between the P and the Q. A very small amount will sufice, but some is necessary. It appears that the formation of hydroquinone monosulfonate is a necessary step in that synergism. OTH, the PC formula does not need sulfite for synergism. When you want both stain and synergism, add as little sulfite as possible – about 0.15 g per liter of the working solution. One can also add ascorbic acid to Stock A solution in amount of about 0.2 g per 100 ml of stock (or 0.04 g per liter of working solution). It will activate the working solution and keep base fog lower.

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  • 12/05/2017
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