D-76 in Higher Concentrationgreenspun.com : LUSENET : B&W Photo - Film & Processing : One Thread
Does anyone try to dissolve Kodak packaged D-76 in a higher concentration form, so as to reduce storage space?
For example, I have a pack of Kodak D-76 powder and per the instruction, this pack is going to make 3.8 litre (1 US gallon) of developer solution.
Is it possible or do you think it is possible to dissolve the pack into 1.9 litre (1/2 US gallon) for storage without any problem nor precipitation?
So when I use this concentrated D-76, I will dilute it 1:1 to make a straight solution and 1:3 to make a conventional 1:1 developer.
Is it possible?
Thank you for your comment and advice.
-- Lonely Boy (firstname.lastname@example.org), June 27, 2001
As long as the full packet of developer dissolves, you shouldn't have any problem.
-- Ted Kaufman (email@example.com), June 27, 2001.
Yeah, and if it doesn't - just add the rest of the water!
-- Patric (firstname.lastname@example.org), June 27, 2001.
OK, thanks for your answer.
I will try this out tonight and tell you the result.
-- Lonely Boy (email@example.com), June 27, 2001.
The result is unsuccessful.
At 1.9 litre, there is a content amount of white powder (in little clum) suspended in the water and refuse to dissolve.
I can say at 1.9 litre, over 95% of the solid can be dissolved.
So I add the remaining water to make 3.8 litre now.
-- Lonely Boy (firstname.lastname@example.org), June 28, 2001.
Solubility is always a problem with dissolving solids into liquids. Besides further increasing the temperature of the water, you might be able to make the solids go into the water by adding an acid or base (I forgot if D-76 is acidic or basic.) Of course this would probably change the development characteristics of D-76. I know a biochemist who is also a B&W aficionado, and he measured the Ksp (solubility) of several developers. D-76 has a relatively low Ksp and requires a lot of water to dissolve the chemicals. Liquids are better in this regard.
-- floren (email@example.com), June 29, 2001.
Now you know, and now we know. Interesting experiment though! :-)
-- Patric (firstname.lastname@example.org), June 30, 2001.