Re: About HCA

nadeaul@nbnet.nb.ca
Sat, 10 Dec 1994 17:40:49 +0300

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

This is not from Kohlbeck, it is from the US patent which I mentioned in
another post.

Luis Nadeau
>
>Jesper Stub Johnsen
>The National Museum of Denmark
>Department of Conservation