Anyone know what the real differences are between wash aids?

[David Allen]

Probably a question more for the technical buffs.

I have happily used Ilford Washaid, Kodak Hypo Clearing Agent, Tetenal Lavaquick and mixed my own using the 200g Sodium Sulfite in 1 Litre of Water formula as a stock solution (I do not add Sodium Bisulfite as I use distilled water).

Are there any practical difference between all of these options?

Thanks,

David.
www.dsallen.de

 

[Sirius Glass]

Six of one and half a dozen of the other. Price, size, shape, color of the bottle or package.

 

[Gerald C Koch]

All the commercial wash-aids work on the same principle. There are minor differences in chemical composition which should have no effect on its use.

Any home brew formula should contain some acidifier like bisulfite or citric acid. This cuts down on mold growth if the solution is saved and helps prevent precipitation from calcium salts. But its main purpose is to insure that the gelatin emulsion is at its iso-electric point which occurs at a pH of approximately 5. This aids in increasing the wash effectiveness and the stability of the emulsion.

Wash Aid

Water ..... 750 ml
Sodium sulfite (anhydr) ..... 100 g
Sodium bisulfite ..... 25 g
EDTA tetrasodium salt ..... 2
Sodium citrate ..... 5
Water to make 1 l

Dilute 1+4 for working solution.

This formula is very close to that of Kodak HCA.

 

[mfagan]

Photographer's formulary residual hypo test will not give accurate results if wash aids containing ammonia have been used -- according to their web site. The MSDS for Perma Wash (if I recall correctly) has ammonia. Now...if the resolution of that hypo test is not satisfactory for you, this wouldn't be relevant. Please don't ask me to recall where I saw how accurate the hypo test is or what the numbers are, though (sorry).

 

[Ian Grant]

Just as effective and a fraction of the cost is to use a solution of Sodium Sulphite of between 1 and 2 % concentration. The EDTA and Citrate are there to help in hard water areas to prevent calcium scum being left on the print surface.

Ian

 

[baachitraka]

20g of Sodium Sulphite in 1l water, works for me. Water in Bremen is rather very good.

 

[john_s]

Given that sodium (meta)bisulphite is readily obtainable in home brewing shops, one might as well add a bit of it to the sodium sulphite given its effect on pH optimizing the gelatin's state.

 

[RalphLambrecht]

Probably a question more for the technical buffs.

I have happily used Ilford Washaid, Kodak Hypo Clearing Agent, Tetenal Lavaquick and mixed my own using the 200g Sodium Sulfite in 1 Litre of Water formula as a stock solution (I do not add Sodium Bisulfite as I use distilled water).

Are there any practical difference between all of these options?

Thanks,

David.
www.dsallen.de

Don't you mean100g sodium sulfite in 1l of stock solution? mixed 1+4 with water makes for a 2%working solution that way

 

[David Allen]

Don't you mean100g sodium sulfite in 1l of stock solution? mixed 1+4 with water makes for a 2%working solution that way

The formula that I have in my notebook is 200g + 1000mL water but diluted at 1 + 9.

Bests,

David.
www.dsallen.de

 

[Doremus Scudder]

There's a case to be made for not mixing a stock solution. Sodium sulfite solutions oxidize with time. After a while, your stock solution won't be any good...

As needed I mix a liter of homemade wash-aid: 1 liter good tap water, 1 Tablespoon sodium sulfite and a generous pinch of bisulfite. It lasts for a few hours; enough for a session.

Fast, always fresh and easier to store than stock.

Best,

Doremus

 

[removed account4]

sometimes companies make fixer remover so it removes
some chemical and leaves trace amounts of others that
are good for prints and film.