Kodak Hypo clearing agent used as sodium sulfite, anhydrous

I have quite a bit of Kodak Hypo Clearing Agent. Can this be used as sodium sulfite (in mixing up developers from scratch) for preventing developer oxidation? I believe it is almost totally sodium sulfite, anhydrous.

Also, while on the subject of clearing agent, over the years I have gathered information on effective washing agent components. I would greatly appreciate knowing if any of the following will NOT be effective in washing papers and films. All (powder or liquid) measurements here are volumetric, in milliliters, not mass (grams): (mix any ONE of the following in water to make one liter of working solution):

20ml table salt (iodized or not)

10ml Kodak Hypo Clearing Agent

20ml household ammonia

8ml sodium sulfite, anhydrous

12ml sodium bicarbonate

10ml sodium carbonate, mono

Please confirm or refute effectiveness for washing fiber based paper more efficiently. Thank you. - David Lyga

1. HCA i believe has bisulphite in it to bring the pH back from alkaline towards neutral. This would have an effect on a developer formulation as it would reduce the pH.

2. For rinse aid, sulphite according to Kodak literature is better than the other suggestions as fixer rinse aid. The other suggestions are probably better than nothing. In particular, the bicarbonate is effective in small quantities in washing water for fibre prints. This is after sulphite rinse aid.

HCA cannot be used to replace sodium sulfite in developers because of the other chemicals it contains. Since you say you have a lot of it then use it as a washing aid rather than any of ther other solutions. Sodium sulfite is commonly available from a number of sources some of them not photochemical suppliers. For example, one canadian photographer got his very reasonably from a food products supplier. Among other uses it's used for keeping salads and sausage fresh.

Washing aids were discovered in WWII when it was found that washing prints aboard ship with sea water was more effective than using plain water. For many years Agfa recommended using a 3% solution of sodium chloride. You would have to use Kosher salt or un-iodized salt for this purpose.

Ammonia and sodium carbonate will cause unwanted softening of the emulsion.

Thank you.

I looked into food grade sodium sulphate when I was building my mix from scratch inventory.
It is locally available from a food product distributor for me, but I could not figure what I was going to do with 50kg of it, the size of the bags they were selling. The price was in line with photo sources, gram per gram., when looking at the qty involved.

I tend to stock up by combining orders from time to time from the Formulary when I am out of a developing agent, etc.

Gerald C Koch said:

You would have to use Kosher salt

Click to expand...

Interestingly, P. Ferricyanide is added to Kosher salt as an 'anti-caking' agent. As the salt isn't yellow, nor does it turn anything bright blue, there can't be much of it present. Kosher salt isn't 'kosher' in the sense of being ritually slaughtered etc., but as suitable for treating meat - it seems Kosher eating involves soaking meat in brine, something about removing the last of the blood.

The purest salt you can get at the grocery is 'pickling salt'. Table and 'Kosher' salt will turn pickling fluid cloudy. True pickling, using lactic acid producing bacilli in addition to salt, has very cloudy pickling fluid indeed.

I just bought 15 kilos of sodium sulfite, its the most common item I mix with.

Gerald C Koch said:

HCA cannot be used to replace sodium sulfite in developers because of the other chemicals it contains. Since you say you have a lot of it then use it as a washing aid rather than any of ther other solutions. Sodium sulfite is commonly available from a number of sources some of them not photochemical suppliers. For example, one canadian photographer got his very reasonably from a food products supplier. Among other uses it's used for keeping salads and sausage fresh.

Washing aids were discovered in WWII when it was found that washing prints aboard ship with sea water was more effective than using plain water. For many years Agfa recommended using a 3% solution of sodium chloride. You would have to use Kosher salt or un-iodized salt for this purpose.

Ammonia and sodium carbonate will cause unwanted softening of the emulsion.

Click to expand...

Nicholas Lindan said:

Interestingly, P. Ferricyanide is added to Kosher salt as an 'anti-caking' agent. As the salt isn't yellow, nor does it turn anything bright blue, there can't be much of it present. Kosher salt isn't 'kosher' in the sense of being ritually slaughtered etc., but as suitable for treating meat - it seems Kosher eating involves soaking meat in brine, something about removing the last of the blood.

The purest salt you can get at the grocery is 'pickling salt'. Table and 'Kosher' salt will turn pickling fluid cloudy. True pickling, using lactic acid producing bacilli in addition to salt, has very cloudy pickling fluiPickling salt is oh.d indeed.

Click to expand...

Not potassium ferricyanide but a very, very small amount of sodium ferrocyanide is used.

According to the Salt Institute kosher salt contains no additives.

The problem with pickling salt is that it is often available only during pickling season and hard to find during other times of the year.

While several salts can be used as a washing aid, research by Kodak indicated that sodium sulfite was the most effective.
www.chemistrystore.com sells 3# for $5.64, 13# for $18.98 plus shipping.

Gerald C Koch said:

Not potassium ferricyanide but a very, very small amount of sodium ferrocyanide is used.

Click to expand...

Ah, thanks for clearing that up -- it's been a head scratcher for years.

Gerald C Koch said:

According to the Salt Institute kosher salt contains no additives.

Click to expand...

Well, as it isn't really 'kosher', I think it depends on the maker of the salt. I know the kosher salt my grocery store carries has ferrocyanide in it. The pickling salt has nothing in it [at least at my grocery].

Mike Wilde: do be careful: sodium sulphate is not the same as sodium sulfite. - David Lyga

Pickling salt can contain anticaking agents. The only guarantee with this salt is that it will not produce a cloudy brine.