Sodium carbonate relative to HCA for clearing FB paper

[Julian Pearce]

The data sheet on Adox MCC paper says to use a 1% solution of sodium carbonate after fixing as a means of reducing wash time. Other recommendations (eg Anchell's Darkroom Cookbook) say to use HCA, although Anchell further says for clearing paper cf film to use HCA made from sodium sulfite without any sodium bisulfite to "improve the paper's gloss". I'd be interested in observations on the difference between sodium carbonate and sodium sulfite as a means of speeding up washing of fibre based papers.

My experience so far with sodium carbonate is that even though I've been doing a brief rinse between the fix (Ilford Hypam) and the sodium carbonate wash there's a slight ammonium smell after several prints are cleared. Thanks for your help. Julian

[D. Bryant]

The data sheet on Adox MCC paper says to use a 1% solution of sodium carbonate after fixing as a means of reducing wash time. Other recommendations (eg Anchell's Darkroom Cookbook) say to use HCA, although Anchell further says for clearing paper cf film to use HCA made from sodium sulfite without any sodium bisulfite to "improve the paper's gloss". I'd be interested in observations on the difference between sodium carbonate and sodium sulfite as a means of speeding up washing of fibre based papers.

My experience so far with sodium carbonate is that even though I've been doing a brief rinse between the fix (Ilford Hypam) and the sodium carbonate wash there's a slight ammonium smell after several prints are cleared. Thanks for your help. Julian

Have you performed a residual fixer test on the papers cleared with sod. carb. ?
You probably need to add some sodium sulfite or bisulfite. I would ignore Anchel's advice for modern papers.

I recommend using a commercial clearing product such as Kodak HCA or PermaWash. It just keeps life simple. And clear in batches to conserve chemicals.

Don Bryant

[neil poulsen]

Steve Anchell's advice is interesting. It's worth giving a it try for a particular paper. I gather that using HCA made from Sodium Sulfite without Sodium Bisulfite is to use a solution of water and Sodium Sulfite alone.

[IanG]

I've used Sodium Carbonate as a wash aid and it works well. It was Agfa's recommendation for their B&W papers.

2% plain Sodium sulphite solution is the ideal Hypo clearing agent, cheap and efficient. The only downside can be in areas of very hard water as the sulphite precipitates the Calcium which can form a scum on the prints (or negatives)

Commercial HCA is osually balanced with citrate & EDTA (or similar) to cope with hard water.

Ironically prints wash faster in hard water than soft :D

Ian

[evan clarke]

I've used Sodium Carbonate as a wash aid and it works well. It was Agfa's recommendation for their B&W papers.

2% plain Sodium sulphite solution is the ideal Hypo clearing agent, cheap and efficient. The only downside can be in areas of very hard water as the sulphite precipitates the Calcium which can form a scum on the prints (or negatives)

Commercial HCA is osually balanced with citrate & EDTA (or similar) to cope with hard water.

Ironically prints wash faster in hard water than soft :D

Ian

And you can't beat knowing the ph of all your liquids, including your water. It's apples vs. oranges any other way..EC

[D. Bryant]

And you can't beat knowing the ph of all your liquids, including your water. It's apples vs. oranges any other way..EC

Eastman Kodak produces their commercial chemical products with all of those variables in mind, hence my recommendation to use HCA or Permawash. I find the productivity component of mixing common pre-packaged darkroom chemicals worth the extra expense.

For more exotic and non mainstream formulas home mixing can't be beat. But for fixer and hypo-clear I found a long time ago pre-packaged products made for silver gelatin emulsions saved me time and aggravation. I also use an acid stop and fixer for all film developers including pyro. I have for decades and it works fine.

Having said that most photographers under-utilize (waste) their fixers and clearing agents regardless of how it has been formulated by dumping prematurely.

Don Bryant

[Julian Pearce]

Thank you for all the comments. I've also just come across a passing comment on the Apug site (in a thread mainly on water usage) where there is a suggestion that sodium carbonate tends to soften emulsions and hence shouldn't be used with papers which don't contain hardeners (such as, so it is claimed, Foma). All things considered sounds better to stick with HCA, either commercially produced or sodium sulfite. Julian

[Doremus Scudder]

Interesting to know about using sodium carbonate as a wash aid. It might be something to use in a pinch.

Don's advice is good, although I generally mix my own wash aid using sodium sulfite and a pinch of metabisulfite. I can mix any amount I need easily and quickly. This is so much more convenient and inexpensive than mixing an entire batch of HCA or the like that it really pays to have a 5lb jar of sulfite in the cupboard. I imagine a proprietary formula with EDTA and buffers would be a good idea if I were using very hard water or well water though.

Just to mention, I've been using acid stop and fix with pyro developers for years with fine results (and some cool florescence from time to time). The water-stop/alkaline fixer actually caused some mottling-streaking problems which I think were caused by carried-over developer being reactivated in the alkaline fix combined with turning on the lights a bit early...

Best,

Doremus Scudder

[IanG]

Just to mention, I've been using acid stop and fix with pyro developers for years with fine results (and some cool florescence from time to time). The water-stop/alkaline fixer actually caused some mottling-streaking problems which I think were caused by carried-over developer being reactivated in the alkaline fix combined with turning on the lights a bit early...

Best,

Doremus Scudder


There are good reasons why Ilford, Kodak, Agfa etc have never marketed an alkaline fixer for B&W use, it's due to the possible carry over and development restarting in the fixer and also dichroic fogging being formed. This matches your experiences.

It's even more important that a stop bath is used before an alkaline fixer for this reason.

Ian

[D. Bryant]

The water-stop/alkaline fixer actually caused some mottling-streaking problems which I think were caused by carried-over developer being reactivated in the alkaline fix combined with turning on the lights a bit early...


I had similar results when not using an acid stop.

Don