Archived posting to the Leica Users Group, 2009/12/10

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Subject: [Leica] Kodak discontinues some chemicals
From: benedenia at gmail.com (Marty Deveney)
Date: Fri, 11 Dec 2009 13:45:31 +1030
References: <ee8fa51c0912101740j74953462y989f634c8c8ea19f@mail.gmail.com> <C7471876.5A255%mark@rabinergroup.com>

Sodium ascorbate works better than ascorbic acid, because it changes
the pH of the developer less.  It works, but Xtol is so great because
of the relatively low pH (kodak calls it 'weakly alkaline' or
something) with high buffering capacity.  To replicate this you need
to mix up a comparable buffer.  I have about a hundred emails archived
somewhere that went back and forth between me and the late John Black
(who I think you knew) about this.  It's not that easy.  He liked
tris- buffers.  I preferred metaborate-boric acid.  I miss
conversations with that guy.

Marty


On Fri, Dec 11, 2009 at 12:58 PM, Mark Rabiner <mark at rabinergroup.com> 
wrote:
>> Indeed - chemistry in particular is very easy to DIY. ?Making Xtol
>> isn't so easy, but most everything else is no harder than following a
>> recipe.
>>
>> Marty
>
>
> People just ad a tab of ascorbic acid to their D76 1:1 and they do fine 
> from
> all I hear. Maybe even better. You can even use powdered ascorbic acid of
> some sort you might not get from a vitamin store but a chemical place.
> Xtol has Phenidone the D76 ?is Elon or Metol more poisonous but all in all 
> a
> much sharper and better silver reducer than Phenidone.
>
>
> Mark William Rabiner
>
>
>
>
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In reply to: Message from benedenia at gmail.com (Marty Deveney) ([Leica] Kodak discontinues some chemicals)
Message from mark at rabinergroup.com (Mark Rabiner) ([Leica] Kodak discontinues some chemicals)