For a number of reasons I have been away from alternative printing for a couple of years and am now in a position to start printing again. However I notice that potassium dichromate (I use it for contrast control in the kalitype process) is not readily available to individuals in the UK and although I have a small amount of chemistry remaining I was wondering whether any one could possible help with a couple of questions I have:
1. Can you substitute sodium dichromate for potassium and if so is it obtainable in the UK?
2. What is the shelf life of 5% potassium dichromate solution? (I have about 80ml made up which is I guess about 3 years old).
I'm guessing this has caused a few problems to other UK alt printers and wonder how this lack of availability of potassium dichromate has been over come?