Re: sodium citrate, ammonium citrate, bleeding of borders

Sandy,
In what way does the acidity have a big impact on printing? In the way the
print looks finally or in the way it processes? I think a while back you had
said that you get staining if the developer does not stay acid but I am not
seeing that happen.

BTW, Sam also told me you've tested am and sod side by side and may know the
speed/dif between the two. Does your result match mine--sod being a bit
lower contrast, 1/4 stop slower maybe at most, and a bit yellower in tone?
Chris

>I use sodium citrate for printing kallitype, and sometime with
> palladium (though for palladium I prefer potassium oxalate). What I
> use is Trisodium Citrate, C6H5Na3O7, 258.07. When mixed with
> distilled water the resulting pH is about 7.0. I bring this down to
> about pH 6.0 by adding more citric acid to the mix, and this has a
> big impact on printing.

One could also add citric acid to an ammonium
> citrate solution to reduce pH.
>
> In any event, I do agree that it would be best to test these two
> solutions at the same pH to create a valid comparison in printing
> characteristics, because pH does make a big difference, and you
> especially want to avoid allowing the solutions to become slightly
> base.
>
>
> Sandy
>
>
>
>
>
>>Oh pooh, Roger! I threw away the jar. I knew I should've kept it.
>>
>>I got it from Tri-Ess when it was in business, but since they closed
>>I threw away the catalog, too, so I can't even check back. But if
>>someone has an old catalog of TriEss it would be in there. I know
>>it was written on the label, anyway.
>>I had no idea there were three types!
>>Chris
>>----- Original Message ----- From: "permadocument" <info@permadocument.be>
>>To: <alt-photo-process-l@usask.ca>
>>Sent: Monday, July 24, 2006 2:18 AM
>>Subject: Re: sodium citrate, ammonium citrate, bleeding of borders
>>
>>>Dear Chris,
>>>
>>>Can you tell us what sodium citrate you used; monosodium (pH= 3,4-4,0),
>>>disodium (pH=5,0) or trisodium (pH=7,5-9,0)?
>>>Thanks,
>>>Roger
>>>
>>>--
>>>Roger Kockaerts
>>>Permadocument - pH7
>>>Rue des Balkans, 7
>>>B-1180 Brussels
>>>Tel.:32-2-347 66 76
>>>Fax: 32-2-344 43 04
>>>TVA: BE 0438 246 889
>>>web page: <http://www.permadocument.be>
>>>
>
Received on 07/24/06-09:23:54 AM Z