[pure-silver] Re: D-76 and variations
- From: DarkroomMagic <info@xxxxxxxxxxxxxxxx>
- To: PureSilverNew <pure-silver@xxxxxxxxxxxxx>
- Date: Mon, 28 Nov 2005 19:31:12 +0100
Gerald
Is that why I see no rise in activity in ID-11 if I seal it from air
completely?
Regards
Ralph W. Lambrecht
http://www.darkroomagic.com
On 2005-11-28 19:04, "Koch, Gerald" <gkoch02@xxxxxxxxxx> wrote:
> The problem with the rise in pH of D-76 with time is due to the
> oxidation of hydroquinone. This is a fairly complex reaction in which
> OH- ions are produced. It has nothing to due with either carbonates or
> borax.
>
> -----Original Message-----
> From: pure-silver-bounce@xxxxxxxxxxxxx
> [mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of John Black
> Sent: Monday, November 28, 2005 12:51 PM
> To: pure-silver@xxxxxxxxxxxxx
> Subject: [pure-silver] Re: D-76 and variations
>
>
>
>>
>>
>> The original D-76 formula and Ilford's published formula for ID-11
>> are:
>>
>> Water (at 125F or 52C) 750.0 ml
>> Metol 2.0 grams
>> Sodium Sulfite, dessicated 100.0 grams
>> Hydroquinone 5.0 grams
>> Borax, granulated 2.0 grams
>> Water to make 1.0 liter
>>
>
> Seems like I remember the OLD original prewar formula for D76 was
> accelerated with Na Carbonate and had a problem with increasing activity
> with aging in solution that was traced to a rise in pH mediated by the
> carbonate. All of which was remedied by switching to borate
> accelerators/buffers. Am I dreaming or was that the case many years
> ago?
>
> JB
>
>
>
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