Re[2]: About HCA

NADO000 (LNADEAU@unb.ca)
Fri, 09 Dec 94 15:22:18 -0400

>>
>> As far as I know the recipe of Kodak HCA is not published. According to

Correction. It is published in a US Patent, which I believe is
mentioned in my first book, or elsewhere. I have it around here
somewhere. I'll try to look it up this week-end

Luis Nadeau
NADEAUL@NBNET.NB.CA

>> Runo Kohlbeck (Kohlbeck: Bevarandet av Fotografiska Bilder (in
>> Swedish) Conservation of Photographs, School of Conservation,
>> Copenhagen, 1987, pp. 78-79) KHCA is made of a 2% buffered and
>> stabilised solution of Sodium Sulfite. Kohlbeck say that you can make your ow
>> solution by mixing 20 g of Sodium Sulfite (Na2SO4, dry), 5 g Sodium
>> Bisulfite (NaHSO3) and 0,5 g EDTA tetrasodium. This is for 1 liter of
>> working solution. I do not know the capacity of this solution, but it
>> might be the same as recommended for the KHCA.
>>
>> Jesper Stub Johnsen
>> The National Museum of Denmark
>> Department of Conservation
>>
>
>Kodak also adds sodium citrate. Kodak lists four ingredients on the
>package: Sodium sulfite, Sodium metabisulfite, Sodium citrate, and EDTA.
>
>- dave
>