E6/7 First Developer Formula. The formula published in the CRC N/L is the official Kodak Formula but needs interpretation to enable the normal worker to be able to make it up. All the chemicals are available, but not readily, and in some cases it is not necessary to go to the trouble of obtaining them. It is essential to use Dimezone `S` and Potassium Hydroquinone Monosulphonate in this developer - there will be colour shifts if these materials are substituted. The inhibited potassium sulphite solution puzzles many people and no one can really decide what is meant by an inhibitor in this particular solution. It is available as a 54% solution but is hardly worth the effort unless you lie near to the supplier. 22.7 gms. of Sodium Sulphite proves a straight alternative which is in almost universal use. In the same way Kodak anti-calcium is available but only in large quantities and can be substituted by EDTA (Na2). Note that Kodak anti-calcium is NOT Calgon, which should not be used. 1.0 gm. of EDTA (Na2) will substitute effectively for anti-calcium. In making up this solution I use a 10% solution of Sodium Thiocyanate and a 0,0% solution of Sodium Iodide rather than weigh out small amounts each time. I also use a 10% solution of Sodium Bromide for the same reason. When making up the solution I omit the Potassium Hydroxide initially and add it when adjusting the pH if this is low, most workers will find that this addition is not necessary. The di-ethylene glycol previously recommended in the original E6 formula is no longer used. E6/E7 Colour Developer formula. As in the First developer Kodak anti-calcium can be substituted, in this case by Calgon, and 1.0 gm. has been found effective. For those who wish to make up the solution as laid down they should use solid potassium hydroxide rather than the 45% solution which may be difficult to find. 31.2 gms. are required of the commercial potassium hydroxide. The use of Pot. Hydroxide and the 85% solution of phosphoric acid will possibly cause problems to a number of people, not the least because of the `spitting` which can take place when the acid is added to the highly alkaline solution. I suggest if these ingredients are not readily available, or the hazard of handling them is to be avoided then 30 gms. of tri-sodium phosphate be used instead but it is essential to use the HS 104 in the solution together with reputable grade of CD3. As regards the latter I suggest that this is made up as a solution:-
The basic developer is made up without the CD3 which is added just prior to use at the rate of 12 mls. per 300 mls. of developer solution. Be careful when measuring this out since there is a very strong smell of sulphuric dioxide until the CD3 solution has gone into the developer. A lot of the CD3 about at the moment (1988) is not of very high quality and has caused some colour casts to result. Reversal Bath. The reversal agent is Stannous Chloride. Acetic Acid may be used in place of the proprionic acid, 10 mls. being required as a substitute. EDTA (Na2) may be used in place of the anti-calcium. 3,0 gms. being used, Calgon may be used as an alternative, in this case. |
