Kodak Hypo Clearing Agent - mixing

[RH Designs]

Hi all

I've not used Kodak HCA before, and the instructions state it should be mixed to make 3.8 litres of stock solution which is then diluted 1+4. Is there any reason not to mix it double strength (i.e. to 1.9 l and dilute it 1+9) ? That would be more convenient for me to store. The issue I imagine is whether the powder would all dissolve properly in the smaller amount of water. Has anyone any comments on this please?

Thanks

Richard

 

[Claire Senft]

I do not know if it will all dissolve in that amount of water. Try it at room temperature. If it dissolves fine, if not add more water.

 

[Tom Hoskinson]

Kodak HCA is mostly Sodium Sulfite. HCA may also contain small amounts of sequestrant (like an EDTA, or Sodium Hexametaphospate, to deal with hard water) a small amount of Sodium MetaBisulfite may also be present ( for buffering).

Sodium Sulfite (anhydrous) solubility:
312 g/l (H2O / 20ºC)

An effective HCA can be mixed by dissolving 20 -25 grams (about 1 teaspoon) of Sodium Sulfite in a liter of water. This solution can be buffered (if desired) by adding about 5 grams of Sodium Bisulfite)

 

[RH Designs]

Thanks both for the answers - this evening I tried mixing the stuff up in 1.9 litres and it dissolved with no problem at all

Regards
Richard

 

[dancqu]

Thanks both for the answers - this evening I tried mixing
the stuff up in 1.9 litres and it dissolved with no problem at all.
Regards Richard

Did you note the temperature? Dan

 

[RH Designs]

Dan -

Kodak recommends mixing at 27C; when I checked the water was arround 28C. It's still all dissolved this morning now it's cooled down to about 15C.

Regards
Richard