PQ Universal Recipe

[terryaking]

Has anyone the recipe for PQ Universal ?
I am 8000 miles from own book shelf and Google does not help.

Terry King

[BBW]

http://www.apug.org/forums/forum216/...id-11-d76.html

[Keith Tapscott.]

Has anyone the recipe for PQ Universal ?
I am 8000 miles from own book shelf and Google does not help.

Terry King

Terry, the formula I have for P.Q. Universal is on page 92 of Ilford Monochrome Darkroom Practice (second edition) by Jack H Coote as follows:

Sodium sulphite, anhydrous = 50 grams
Sodium carbonate, anhydrous = 60 grams
Hydroquinone = 12 grams
Phenidone = 0.5 grams
Potassium bromide = 2 grams
Benzotriazole (1% solution) = 20 ml
Water to 1 litre.

I am not sure if it`s a typo though, as it looks like a P.Q. version of ID-20 which they call ID-62 and is usually diluted 1+3 rather than 1+9 through to 1+19.

[IanG]

PQ Universal is very close to ID-62 but around 2.5X more concentrated. To overcome solubility issues at the higher concentration, the Sodium Carbonate is replaced with a smaller quantity of Potassium Carbonate and Sodium Hydroxide to achieve the same pH.

Ilford call ID-62 a Universal PQ developer, and once made up there's no differences between the two developers.

The substitution of Sodium Carbonate with Potassium Carbonate and Sodium or Potssium Hydroxide in commercial liquid concentrate developers is common to Ilford, Agfa and Kodak.

Ian

[terryaking]

Thanks. I am very grateful for that. Contingencies demanded that we could not go for perfection. We have compromised on Multigrade which is here.