From: Sandy King (sanking@clemson.edu)
Date: 08/21/02-03:25:24 PM Z
Julian wrote:
>Hi,
> one thing I have noticed when doing a batch of VDB prints, is that if I mix
>all three solutions together to make a single working solution it just
>doesn't last. It seems to go off (oxidise?) and makes producing a decent
>print impossible even the next day.
>I tracked the problem down to the tartaric acid, having found that the other
>two solutions will keep well for months in dark brown bottles. The tartaric
>acid solution will not work even the next day. I figure the cost of the
>tartaric acid to be almost negligible and therefore mix this fresh before
>any printing batch- a bit of a pain, but I always get a decent result.
>
>The f.A.citrate, btw , will always generate a certain amount of sludge on
>storage. I have found this to be harmless to my prints as long as it is not
>disturbed in the bottom of the bottle..
>
>All the best,
>
>Julian.
Very curious. I have not found that the combined solution goes bad,
even after many months. Just a few days ago I finished a large bottle
of the combined A, B, and C solution that was mixed in January or
February of this year and the results at the end seemed as good as
what I saw at the beginning of the year.
Sandy King
>
>
>
>
>
>
>----- Original Message -----
>From: "Don Bryant" <dsbryant@mindspring.com>
>To: <alt-photo-process-l@sask.usask.ca>
>Sent: Wednesday, August 21, 2002 12:15 PM
>Subject: Re: Van Dyke Brown Mixing question
>
>
>> ----- Original Message -----
>>
>> >
>> > Don:
>> >
>> > I went through this same problem with the list a few months ago, and
>> > subsequently have mixed in part C very slowly as per the advice I
>> received.
>> > The batch I made last Sunday was pretty much clear by Monday evening,
>with
>> > just a little sludge. Yours will probably be fine tomorrow.
>> >
>>
>> Thanks Clay, I'll keep an eye on it.
>>
>> Don Bryant
>>
>>
>>
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