Divided D76 precipitate

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Lew - 18 Feb 2004 16:54 GMT

I've just had my Formulary dD76 mixed for a week. Sol A has a dirty,
brownish, snowflake sized precipitate in it. Has anyone else seen this? Is
it normal or what?
-Lew

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Martin Jangowski - 18 Feb 2004 22:02 GMT

> I've just had my Formulary dD76 mixed for a week. Sol A has a dirty,
> brownish, snowflake sized precipitate in it. Has anyone else seen this? Is
> it normal or what?

Did you use tap water?

Martin

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Lew - 18 Feb 2004 22:22 GMT

Yes, but here in Brooklyn, NY the tap water is exceptional & I've never had
any problems over the years with a wide variety of chemistries.
-Lew

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Dan Quinn - 19 Feb 2004 23:20 GMT

> I've just had my Formulary dD76 mixed for a week. Sol A has a dirty,
> brownish, snowflake sized precipitate in it. Has anyone else seen
> this? Is it normal or what?

Speaking of ALL photographic solutions, I can not think of ONE
instance in which particulate matter is a contributing ingredient in
the working solution.
With repeated use some solutions do generate a little sludge. Divided
D76 should have no precipitate, A or B.
Just a thought; how much film got "mixed" into part A? Dan

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Lew - 20 Feb 2004 05:08 GMT

Dan:
You're right, I really don't know whether it's precipitate or not. The
solution was clear while unused. After 2 rolls of film the gunk appeared. I
filtered a quantity to use today and the results look fine. Still like to
know what's happening, though.
-Lew

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Stefan Kahlert - 20 Feb 2004 13:47 GMT

> Dan:
> You're right, I really don't know whether it's precipitate or not. The
> solution was clear while unused. After 2 rolls of film the gunk appeared. I
> filtered a quantity to use today and the results look fine. Still like to
> know what's happening, though.
> -Lew

As Martin suggested, this is what normally happens when using the
published formula of D76 or the alike made up with tap-water. First
they are clear, after developing a roll or two you get some
precipitate in the solution.

I'm using Barry-Thorntons Two-bath (a metol/borate formula) this way
with no ill-effects so far but this may depend on the rest of the
processing conditions. Therefore, I would recommend to use distilled
water to make stock as well as working solutions that do not contain
any sequestering agents.

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