Concentration of Kodak Indicator Stop Bath?

[Steve Goldstein]

I'm curious, does anyone know? I'm talking about the stuff as it comes in the bottle, before dilution to working strength. It only says "concentrated" on the round grey bottle I have, and not even that on my older square HDPE bottle.

Not important, obviously.

 

[Steve Goldstein]

Thanks. It didn't occur to me to work it out this way combining bottle instructions and Darkroom Cookbook info.

That suggests that the stuff sold by Kodak should be around 42% ((6/4) * 28), which makes sense based on my very subjective nose-o-meter. It doesn't smell as nasty as the glacial I recently diluted down to 28% for safer handling, but it seems nastier the 28% result.

 

[David Lyga]

I believe that Indicator is 80% of the potency of glacial. - David Lyga

 

[ChuckP]

Doesn't indicator stop bath use 2 oz per gallon for general use working solution? That's what I've always used.

 

[Steve Goldstein]

Yup, just checked the bottle, it's 2 oz per gallon. That makes it ~84%. At that strength I wonder why they dilute it at all, maybe just to lower the "freezing" point? Glacial solidifies around 61 degrees Fahrenheit, or 11 Celsius.

 

[David Lyga]

Yes, Steve, for the longest time I considered Indicator to be the SAME potency as glacial. Then I actually did the math, backing into the actual percentage by using the recommended amounts to make a liter, as told by Kodak. - David Lyga