At 09:58 PM 11/26/2017, `Richard Knoppow wrote:
This was mixed from scratch D-76. The effect was discovered early and there is a long paper about its cause and cure. Don't have the citation handy. I am not sure I remember the explanation exactly but the cure was to buffer the solution by using a combination of Borax and Boric acid. The commercial packaged version is either this or something close to it. The experimental data shows it is much more stable as far as activity than the original. There is an alternative formula using Kodalk (sodium metaborate pentahydrate).==========================================================
The formula is:
Kodak D-76d Buffered Borax Developer
Water (at about 125F or 52C)..............0.750 ml
Metol.....................................2.0 grams
Sodium sulfite, desiccated..............100.0 grams
Hydroquinone..............................5.0 grams
Borax, granulated.........................8.0 grams
Boric acid, crystalline...................8.0 grams
Water to make.............................1.0 liter
Mix in order given. Times are the same as for fresh standard D-76
To minimize fog and maximize film speed with fresh developer add
Potassium bromide.........................0.5 gram.
Boric acid powder should not be used as it dissolves only with great difficulty.
