sodium bisulfite = potassium metabisulfite?

eli griggs · Jul 23, 2007

I want to mix up HCA (formula #190, p254) from The Darkroom Cookbook but I do not have sodium bisulfite on hand; can I use potassium metabisulfite to good effect for the stock?

I want to use this with fb paper and film and though I can use sodium sulfite on its' own, wouldn't the addition of either of the two title chemicals be a better, sorry for the pun, solution?

Cheers, Eli

Chris Breitenstein · Jul 23, 2007

What is th formula you are using. I don't know whether you can use potassium Metabisulfite in stead of sodium metabi. I believe that they are both salts, and that potassium carbonate can be used as a substitute for sodium carbonate, but you must use more potassium carbonate then sodium.

Yours;

Ole · Jul 23, 2007

Anything with potassium is bad news in a fixer. Since the purpose of HCA is to remove fixer, I would assume it to be even worse there.

Don't.

eli griggs · Jul 23, 2007

Thanks for the replies and thanks for the heads-up Ole. I thought I had sodium bisulfite on hand but no, none to be found. The closest chemistry company I know of here-abouts wants $20 for 500g and that's not happening anytime soon.

I'll go ahead and mix it up the stock sodium sulfite solution and put the correct chemical on next chemicals order.

Eli

psvensson · Jul 23, 2007

You can probably make a good HCA with just sulfite. The purpose of the bisulfite would be to balance the pH a bit (since it's acidic, while the sulfite is alkaline). With no bisulfite, you'd end up with somewhat alkaline HCA, which I don't think is a problem. You could balance it by adding a little bit of some innocuous acid, like citric.

eli griggs · Jul 23, 2007

My chemistry today is Ansco 130 1:1, tap water stop, TF-4, sodium sulfite HCA 1:7, tap water final wash and if I see anything I like, selenium toner.

I'm printing on graded Oriental Seagull G FB.

I put out a 1400 ml HCA bath, if I were to add add citric acid, what would be a good starting point?

By-the-way, I'd like to pass out a big THANK YOU to Al Gore for inventing the internet!!! I simply love this big, bad world of instant connections and like minded souls sharing their interests.

Eli

dancqu · Jul 23, 2007

eli griggs said:
... sorry for the pun, solution? Cheers, Eli

Double-entendre.

Yes, best to keep potassium away from any thing fixer.
The sodium and ammonium salts of the most soluble
argentous thiosulfate complex are quite soluble.
I suspect that the warning against potassium
has to do with it's little solubility.

I've proposed that minute amounts of impurities from the
water and chemistry can lead to other element extremely
insoluble complexes A cause perhaps of the persistent pink
problem some have with their films. Dan

Tom Hoskinson · Jul 24, 2007

psvensson said:
You can probably make a good HCA with just sulfite. The purpose of the bisulfite would be to balance the pH a bit (since it's acidic, while the sulfite is alkaline). With no bisulfite, you'd end up with somewhat alkaline HCA, which I don't think is a problem. You could balance it by adding a little bit of some innocuous acid, like citric.

Yes eli, you can make a good HCA by dissolving 15 to 20 grams of Sodium Sulfite in a liter of water. You can buffer the solution by adding 5 grams of Sodium Bisulfite. This will result in a solution pH between 6.5 and 8.

You can further lower the pH of the solution and/or sequester calcium and magnesium (if you mix with hard water) by adding 1 gram per liter of citric acid.

A combination of EDTA and Citric Acid are sometimes added to HCA to deal with hard water.

Cor · Jul 24, 2007

sodium bisulphite = sodium metabisulphite?

I searched for below quote, until I realized I read the question incorrect: but I post it anyway since I think it is worthwhile: form Ryuji Suzuki's excellent site:

http://silvergrain.org/wiki/Metabisulfite

Best,

Cor

eli griggs · Jul 24, 2007

Thanks guys, interesting stuff, especially Cor's linked article.

Regrettably, a quick check of Photographers Formulary shows there are no savings to be had by buying the metabisulfite rather than the bisulfite, in one pound jars; I'll look elsewhere latter.

I'm using distilled water for mixing chemistry, though my using tap for stop and wash probably negates the effort.

The stock HCA is 200 grams sodium sulfite in a liter of water, diluted to 1:7 for use. If I added a gram per liter of citric acid to the working solution, without the of either sodium bisulfite or metabisulfite, will that give me a HCA that can be safely used with films? Anchell indicates that sodium sulfite only HCA can soften film emulsions.

Charlotte water is consider soft, according to the 2006 water quality report, with a trace minerals content of 1.8 grains per gallon. Tasty too!

Cheers, Eli

Tom Hoskinson · Jul 24, 2007

eli griggs said:
Thanks guys, interesting stuff, especially Cor's linked article.

Regrettably, a quick check of Photographers Formulary shows there are no savings to be had by buying the metabisulfite rather than the bisulfite, in one pound jars; I'll look elsewhere latter.

I'm using distilled water for mixing chemistry, though my using tap for stop and wash probably negates the effort.

The stock HCA is 200 grams sodium sulfite in a liter of water, diluted to 1:7 for use. If I added a gram per liter of citric acid to the working solution, without the of either sodium bisulfite or metabisulfite, will that give me a HCA that can be safely used with films? Anchell indicates that sodium sulfite only HCA can soften film emulsions.

Charlotte water is consider soft, according to the 2006 water quality report, with a trace minerals content of 1.8 grains per gallon. Tasty too!

Cheers, Eli

Eli, is it correct that you are fixing with TF-4?

If so, HCA is not needed, only a water wash (this can be verified by Photographer's Formulary).

Re Sodium Bisulfite: At The Chemistry Store: http://www.chemistrystore.com/sodium_metabisulfite.htm

a 3lb jar of Sodium Metabisulfite is $10.50. I by a lot of my chemicals from The Chemistry Store on the Internet.

A 3lb pail of Sodium Sulfite is $5.64 at the Chemistry Store.

eli griggs · Jul 24, 2007

Thanks Tom, the Chemistry Store is where I bought my sodium sulfite, a 13 lb. pail IIRC and was on my check it latter list for the other stuff.

Even with the TF-4, I'd rather have a hypoclear bath than do without, especially with FB paper.

I am only using TF-4 with papers; for film I'm using Kodak Professional Fixer.

Eli

Ole · Jul 24, 2007

With TF-4, you're wasting time, water, chemicals and money if you use HCA after fixing. Especially with fiber paper - the (acidic/neutral) HCA takes longer to wash out than the TF-4 would!

A sulfite-only HCA will soften emulsions, but that's part of the function of it. The emulsion will be just the same when washing is finished.

gainer · Jul 25, 2007

Quote from Wikipedia:
"In the brand Stump-Out, it is used in almost a pure form (98%) to cause degradation of lignin, creating pores for fuel adsorption, and consequently, ignition.[1]"

You may be able to find sodium metabisulfite locally under that name.

eli griggs · Jul 25, 2007

Thanks for the tip gainer, I'll give it a look-see.

Ole, I prefer not to waste resources so no more HCA with TF-4.

The reason I am concerned about using sodium sulfite alone in HCA for film is that I am using Ekfe films for the first time and I've see warnings that the emulsions of these films can be more delicate than usual. As I mentioned above, these will be fixed in Kodak Professional Fix.

Eli

dancqu · Jul 26, 2007

[QUOTES=Ole;496571]
"With TF-4, you're wasting time, water,
chemicals and money if you use HCA after fixing."

Are you implying that in some way TF-4 interferes with
the effective use of a HCA?

I'm aware that TF-4 is so loaded with chemistry that
it needs a shacking prior to dilution. TF-2 is less loaded
with chemistry and shares, according to the TF series
formulator, a hca needlessness. Also TF-2 is an easy
mix-fresh at time of use. The dry chemistries used
have a very long shelf life. A no ODOR fix.

"Especially with fiber paper - the (acidic/neutral) HCA
takes longer to wash out than the TF-4 would!"

A HCA is usually slightly to decidedly alkaline. As for
speed and water usage I'd have to do a series of HT-2
tests to believe that TF-4 has any advantage other
than skipping a step. I'd worry having a well used
bath of that fixer and no following hca.

Just a reminder: whatever the fix, greatest chemical
mileage and greatest print longevity come from use
of a two-bath fixer. The only exception being the
single bath very dilute fix. Dan

Tom Hoskinson · Jul 26, 2007

eli griggs said:
Thanks for the tip gainer, I'll give it a look-see.

Ole, I prefer not to waste resources so no more HCA with TF-4.

The reason I am concerned about using sodium sulfite alone in HCA for film is that I am using Ekfe films for the first time and I've see warnings that the emulsions of these films can be more delicate than usual. As I mentioned above, these will be fixed in Kodak Professional Fix.

Eli

Eli, I shoot a lot of 8x10, 5x7 and 120 Efke film. I develop the Efke in Pyrocat (which tans the emulsion) and I fix it either in TF-4 or in a scratch mixed Ammonium Thiosulfate based rapid fixer. I use no short stop and a water wash with no HCA - However, I often use a sodium carbonate bath (higher pH than Sodium Sulfite) to remove residual antihalation and sensitizing dyes. I have no problems at all with emulsion damage.

gainer · Jul 27, 2007

I remember that some time ago there was some research that showed that prints with a small amount of residual thiosulfate lasted longer than those with none. I know I have prints that I made in the 70's that are still in very good shape. I also recall reading somewhere that it might be best not to frame photos under glass.

sodium bisulfite = potassium metabisulfite?

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sodium bisulfite = potassium metabisulfite?

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