Re: About HCA

Claude Seymour (cseymour@cap.gwu.edu)
Fri, 9 Dec 1994 11:01:14 -0500 (EST)

Is this stock or working solution?

Claude Seymour

On Sat, 10 Dec 1994, Jesper S. Johnsen wrote:

> 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.
>
> Jesper Stub Johnsen
> The National Museum of Denmark
> Department of Conservation