metol instead of phenidone : LUSENET : B&W Photo - Film & Processing : One Thread

Hi, I'm thinking of trying a couple of formulas that need phenidone. I lack the ability to measure out small amounts (tenths of a gram) accurately and was thinking of replacing the phenidone with metol (about 10 times the amount). Would appreciate any pointers based on experience. I'm willing to live with the speed loss of metol vis-a-vis phenidone but anyting else to look out for. Thanks, DJ.

-- N Dhananjay (, January 03, 2001


Although Phenidone is broadly used as a 'substitute' for Metol, the detailed constituents of equivalent formulae are quite different.
For instance; ID68 (Phenidone) was formulated to give very similar results to D76 (Metol), but the Phenidone formula is nowhere near the same as the Metol version.
Simply replacing Phenidone with Metol will almost certainly work as a developer, but won't give the same result, and won't have the same development time.

As I see it, there are two ways round this.
1)If the problem is simply one of weighing out, then you can weigh a larger quantity of Phenidone powder, arrange it into a neat shape and simply divide it into 2 or 4, or make up a stock solution of, say, 10 gm in 100ml of distilled water, with 20gm of Sodium Sulphite to preserve it. Then if the formula calls for 0.75 gm, just use a syringe to measure 7.5ml of the solution.
2)Alternatively, use a published Metol formula which is the functional equivalent of the Phenidone one.
The later editions of Jacob's 'Developing', Focal press; gives a whole range of modern(ish) formulae to cover practically every need, and I have a fairly comprehensive library of formulary myself. If you tell me the Phenidone formula, I can most likely find the Metol equivalent for you.

-- Pete Andrews (, January 04, 2001.

The way I have always heard recommended is to make the "stock" solution. I don't think you need quite 20 grams of sodium sulfite to preserve it either, but I will have to check.

10 grams to a volume of 100 ml makes a nice 10% solution to use. A tip, use some alcohol to dissolve the phenidone than dilute with water. The little bit of alcohol won't hurt any formula and will really help to dissolve the phenidone. That tip from Ctein's "Post Exposure."

-- Terry Carraway (, January 04, 2001.

Thank you for the responses. Isn't Phenidone supposed to be a bugger to dissolve? Is it possible to dissolve 10gms in 100ml? Pete, I'll get in touch with you offline for specific formulae. Cheers, DJ.

-- N Dhananjay (, January 04, 2001.

Yes, Phenidone is a bugger to dissolve, in any quantity. It tends to just sit on the surface of the solution, but will dissolve slowly, given vigorous stirring. The alcohol tip is a good one; Benzyl alcohol works best, but Iso-propanol is easier and cheaper to obtain.

-- Pete Andrews (, January 05, 2001.

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