InstantMytol Stock solution

[Cor]

Hi,

I would like to try Instant Mytol in Glycol as an replacement for Xtol. (see (there was a url link here which no longer exists) and Jordan's page at:
http://www.photosensitive.ca/wp/easy-film-developers).

For Xtol I mix the whole 5 liter batch in distilled water, and than put it in glass brown bottles, filled to the top.

From this stock I fill smaller bottles either with 150 ml stock (200 ml bottle) or 250 ml stock (300 ml bottle); and fill these up to the top with distiled water. When I need to process a 35 mm or a 120 roll in my Patterson tank, I take a bottle and enlarge the volume to either 300 or 500 ml 1:1 Xtol. Sound more complicated as it is. I find it fast and convenient, and has kept Xtol going for more than 2 years after mixing. I do store the bottles at 5-10degC.

I would like to apply such a scheme to Instant Mytol, mixed in Glycol; from above:

Stock solution in propylene glycol / triethanolamine:

Start with 13.4 ml hot triethanolamine
25 ml hot propylene glycol
11.5 g ascorbic acid
0.15 g phenidone

Stir until all solids have dissolved (it will take quite a while, and may require the addition of 1-2 ml of water). Dilute with hot propylene glycol to a final volume of 50 ml.

Working solution: The stock solution should keep indefinitely. For use, dilute 1+19 with water containing 60 g/L sodium sulfite — the resulting solution matches the activity of stock XTOL. To create something like XTOL 1+1, dilute 1+39 with water containing 30 g/L sodium sulfite.

So this means for a 120 film, 1:1 end volume 500 ml 12.5 ml stock developer and 15 gr of sulphite.

First question. Is a stock solution of sulphite stable in water? I seem to recall that sulphite in water slowly turns into sulphate.

67.8 gr. sodiumsulphite max. solutes in 100 ml, so a 30% stock of sodiumsulphite should not be hard to make.

Suppose that I would fill a small bottle with 12.5 ml water and 50 ml 30% sulphite, top it off with distilled water. Would you expect this stock to be stable?

Or am I counteracting the preserving properties of the glycol?

Thanks in advance for any input,

Best,

Cor

 

[Alan Johnson]

It's hard to get more than about 125g/L sodium sulfite to dissolve rapidly at 68F IMO.
To get 200 g/L requires stirring periodically over 12 hrs:
http://photo.net/black-and-white-photo-printing-finishing-forum/00Bldt
Potassium Sulfite is more soluble but hard to get,it often comes as bulk solution.

 

[Cor]

It's hard to get more than about 125g/L sodium sulfite to dissolve rapidly at 68F IMO.
To get 200 g/L requires stirring periodically over 12 hrs:
http://photo.net/black-and-white-photo-printing-finishing-forum/00Bldt
Potassium Sulfite is more soluble but hard to get,it often comes as bulk solution.

Thanks for the feedback, Alan

I see the snag now considering solubility of sodium sulfite:67.8 g/100 ml (18 °C, heptahydrate), missed the heptahydrate part, that makes soluting easier. But heptahydrate solid stock contains also sulphate, right?

Ok I could settle for 150 g/l than, would my suggestion still be a viable approach?

Best,

Cor

 

[Alan Johnson]

Dilute solutions of sulfite in absence of air last a long time.I have some Mytol in a full sealed bottle 4yrs old, still worked last time I tried it.I think that what you suggest, which is basically keeping a dilute solution of sodium sulfite in a full sealed bottle, would work fine.