Concentration of Kodak Indicator Stop Bath?

Steve Goldstein · Aug 21, 2015

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 · Aug 22, 2015

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 · Aug 22, 2015

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

ChuckP · Aug 22, 2015

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

Steve Goldstein · Aug 22, 2015

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 · Aug 23, 2015

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

Concentration of Kodak Indicator Stop Bath?

Steve Goldstein

Steve Goldstein

David Lyga

ChuckP

Steve Goldstein

David Lyga

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