Iron Out mixing question

[What About Bob]

I will be using this as a chemical fogging and redeveloper in black and white reversal process.

In recipes that I have seen they show about a tablespoon of sodium dithionite for every 200ml of distilled water with the addition of about 1 teaspoon of sodium carbonate. So I take that to be 45 grams of dithionite to 5 grams (anhydrous), in my case 5.85 grams (monohydrate), of sodium carbonate per 600ml of working solution to be used one-shot.

The version of Iron Out that I recently bought doesn't list sodium carbonate as an ingredient but does list sodium metabilsulfite. I have both sodium and potassium carbonate on hand. I am thinking that the carbonate would neutralize the metabisulfate to a degree but how it would affect the working formula I do not know. Which makes me think: Should I instead order the dithionite powder separately and then add the carbonate or is the carbonate even needed for the Iron Out formula?

I thought to give this chemical step a try. Up to now I have been doing the re-exposre by light and developing with the PQ developer. I actually enjoy doing and viewing the re-exposure step by light,.

 

[Raghu Kuvempunagar]

Dithionite redeveloper needs to be sufficiently alkaline (pH ~10.5) to work effectively. Fortunately, you can always do a clip test with your Iron Out and check if it develops the film completely.

 

[koraks]

a tablespoon of sodium dithionite for every 200ml of distilled water [...] I take that to be 45 grams of dithionite

45g sounds like a heck of a lot to pile on top of a tablespoon. I'd cut that down to maybe 10-15g (and I think that's already far more than enough). Evidently it's not very critical.

 

[What About Bob]

45g sounds like a heck of a lot to pile on top of a tablespoon. I'd cut that down to maybe 10-15g (and I think that's already far more than enough). Evidently it's not very critical.

I agree 45 sounds like overkill. What I went by were the users from old posts going by the tablespoon method for every 200ml of water. I would be using 600ml for final volume. 45 sounds like a waste.

 

[What About Bob]

Dithionite redeveloper needs to be sufficiently alkaline (pH ~10.5) to work effectively. Fortunately, you can always do a clip test with your Iron Out and check if it develops the film completely.

The Iron Out datasheet shows the PH to be in the range of 5.5 - 6.5 I'll use the carbonate and do the clip tests. I should order some PH strips.