Sodium carbonate solution - how long does it keeps?

If one split a developer in active part/carbonate, for how long will
the carbonate solution keep (normal usage - bottle starts full and
goes empty with usage).
I understand that slowly carbonate will become bicarbonate.
Would adding sulphite help? Does it changes pH?

Thanks,

Jorge


Jorge Omar

"Jorge Omar" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> If one split a developer in active part/carbonate, for how long will
> the carbonate solution keep (normal usage - bottle starts full and
> goes empty with usage).
> I understand that slowly carbonate will become bicarbonate.
> Would adding sulphite help? Does it changes pH?
>
> Thanks,
>
> Jorge

Sodium carbonate is the bottom of the line as far as oxidation is concerned.
That indicates that there should be no deterioration in storage. I wouldn't
worry about it. However the material is so cheap and available, I see no
point is long term storage. When preparing my developer, I dump all the old
and start everything from scratch. That way there is never a question as to
when, what, where.

It would be advisable to dump used solutions after use as the carryover of
developer will eventually render the carbonate solution a little "hot" and
the advantage of the two solution technique will be lost.

Truly, dr bob.

On Wed, 16 Jul 2003 08:11:23 -0400, "dr bob" <(E-Mail Removed)> wrote:

>
>"Jorge Omar" <(E-Mail Removed)> wrote in message
>news:(E-Mail Removed). com...
>> If one split a developer in active part/carbonate, for how long will
>> the carbonate solution keep (normal usage - bottle starts full and
>> goes empty with usage).
>> I understand that slowly carbonate will become bicarbonate.
>> Would adding sulphite help? Does it changes pH?
>>
>> Thanks,
>>
>> Jorge
>
>Sodium carbonate is the bottom of the line as far as oxidation is concerned.
>That indicates that there should be no deterioration in storage. I wouldn't
>worry about it. However the material is so cheap and available, I see no
>point is long term storage. When preparing my developer, I dump all the old
>and start everything from scratch. That way there is never a question as to
>when, what, where.
>
>It would be advisable to dump used solutions after use as the carryover of
>developer will eventually render the carbonate solution a little "hot" and
>the advantage of the two solution technique will be lost.

I think he means split stock and not divided development. Of course I
agree that carbonate will keep a very, very long time either in solution or dry.
If making a stock solution one does need to be aware of it's solubility though.
Carbonate can precipitate out of solution to form something like crystals in the
bottom of the bottle.

John

Yes, it's to split a developer and not for two bath development.

Reason for the question is 'cause I found two times in the NET - 3
months and one year.
Very coherent...

Thanks,

Jorge

On 16 Jul 2003 13:52:59 -0700, (E-Mail Removed) (Jorge Omar) wrote:

>Yes, it's to split a developer and not for two bath development.
>
>Reason for the question is 'cause I found two times in the NET - 3
>months and one year.
>Very coherent...

Can you give me some more details on exactly what you are contemplating ?
Something like FX-2 ?

John

Like...

About 20 yrs ago (in another photo life) I've used the better part of
an HC-110 bottle at a dillution of 1+63 (concentrate) plus carbonate
(1g/L) and benzotriazole (1cc/L of 1% solution).

I'm testing TMX with this soup (it becomes kind of compensating) to
see if I can tame blown higlights.

The reason for the question is if carb solution keeps a short time, I
would mix less.

Looks like I do not have to worry about keeping properties.

Jorge


John <(E-Mail Removed)> wrote in message news:<(E-Mail Removed)>. ..
> On 16 Jul 2003 13:52:59 -0700, (E-Mail Removed) (Jorge Omar) wrote:
>
> Can you give me some more details on exactly what you are contemplating ?
> Something like FX-2 ?
>
> John

On 17 Jul 2003 05:12:13 -0700, (E-Mail Removed) (Jorge Omar) wrote:

>> Can you give me some more details on exactly what you are contemplating ?
>> Something like FX-2 ?
>
>About 20 yrs ago (in another photo life) I've used the better part of
>an HC-110 bottle at a dillution of 1+63 (concentrate) plus carbonate
>(1g/L) and benzotriazole (1cc/L of 1% solution).
>
>I'm testing TMX with this soup (it becomes kind of compensating) to
>see if I can tame blown higlights.

Highlight contrast is mostly effected by the length of the development and
to a lesser extent the activity level of the developer. Dilute your working
solution a little more (1:74) and/or shorten your development time in 5%
increments until you get the contrast under control.

>The reason for the question is if carb solution keeps a short time, I
>would mix less.
>
>Looks like I do not have to worry about keeping properties.

No, you don't.

John

Thanks, John.

I will start by lowering dev time (first test was 8 min @20C).

Jorge

John <(E-Mail Removed)> wrote in message news:<(E-Mail Removed)>. ..
> On 17 Jul 2003 05:12:13 -0700, (E-Mail Removed) (Jorge Omar) wrote:
>
> >> Can you give me some more details on exactly what you are contemplating ?
> >> Something like FX-2 ?
> >
> >About 20 yrs ago (in another photo life) I've used the better part of
> >an HC-110 bottle at a dillution of 1+63 (concentrate) plus carbonate
> >(1g/L) and benzotriazole (1cc/L of 1% solution).
> >
> >I'm testing TMX with this soup (it becomes kind of compensating) to
> >see if I can tame blown higlights.
>
> Highlight contrast is mostly effected by the length of the development and
> to a lesser extent the activity level of the developer. Dilute your working
> solution a little more (1:74) and/or shorten your development time in 5%
> increments until you get the contrast under control.
>
> >The reason for the question is if carb solution keeps a short time, I
> >would mix less.
> >
> >Looks like I do not have to worry about keeping properties.
>
> No, you don't.
>
> John

"Jorge Omar" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> If one split a developer in active part/carbonate, for how
long will
> the carbonate solution keep (normal usage - bottle starts
full and
> goes empty with usage).
> I understand that slowly carbonate will become
bicarbonate.
> Would adding sulphite help? Does it changes pH?
>
> Thanks,
>
> Jorge

Sodium Carbonate slowly absorbs carbon dioxide from the
air which lowers its pH. However, this is a slow process and
for a strong concentration of carbonate in a closed
container I think is not a practical problem. I think such a
solution will keep for many months, perhaps much longer.
--

---
Richard Knoppow
Los Angeles, CA, USA
(E-Mail Removed)

On Fri, 18 Jul 2003 12:49:00 -0700, "Richard Knoppow" <(E-Mail Removed)>
wrote:

> Sodium Carbonate slowly absorbs carbon dioxide from the
>air which lowers its pH. However, this is a slow process and
>for a strong concentration of carbonate in a closed
>container I think is not a practical problem. I think such a
>solution will keep for many months, perhaps much longer.

Richard,

Do you remember anything about carbonate affecting the glass ? I have a
vague memory of seeing glass "frosted" by carbonate stock after it had sat for
some time on the shelf.

John