- PROCESSING WITH YOUR OWN SOLUTIONS -

When you have had some experience of processing with kits, it is only a short step to making up your own solutions from raw chemicals. For most of the published formulae the chemicals can be obtained in small quantities from the Club’s Chemical Stock.

You will of course require a balance to weigh out the chemicals and it is essential to have a couple of small graduated cylinders (10cc& 25cc) for measuring small quantities of percentage solutions.

Once you have bought the chemicals you require, it costs very little to develop your films. Your solutions will also be fresh as you canmix exactly enough to process the films you have to hand.

The solutions given in the accompanying formulae will last in good condition for varying times. The developers have been designed tohave a life of about six weeks in their concentrate form, while the other solutions will have at least six months life.

Working capacity of the developing solutions is 10 films per litre, The other solutions have a life of 25 films per litre. Make up two
Stop Baths and on no account mix them, as there is a carry over of chemicals from the previous bath once they have been used. Mixingthem up will give an unwanted colour cast to your transparencies. It makes good sense to mix up 1 litre of the Bleach, Fixer, Stop Bath, and Stabilizer, and to mix enough Developing solution for your immediate needs. It is quite straightforward to work out the quantities of chemicals for 300ml or 500ml etc. with the help of a pocket calculator.

Some chemical balances will not cope with less than 1gm. There is a simple way to remedy this - use a percentage solution. These are
simple to make up. In a graduate cylinder place a small amount of water. Weigh out the chemical to say 25gms. Stir into the cylinder
and carefully add water to 250 ml. You now have a 10% solution. If the formula calls for 0.7gm just measure 7ml of the solution. It ismore convenient than trying to weigh out the small amount.

FORMULAE

Most of us have our own pet formulae. All are based on British & American substitutes for Kodak’s formulae. They are designed to give results close enough to the original to satisfy most workers.

One of the formulae which has given our members good results is given here. It has developers which have been based on work by the late Arnold Moorhouse, when he was a member of the Club.

The formulae is suitable for Fuji and Ektachrome. The later formulae based on the E6 process gives superior results with all E6 film - but needs more skill and better equipment to make it up.