Alan Johnson had the idea of dissolving sodium sulfite into water ahead of time, creating a sulfite solution that you use over a period of one or more months. Using a concentrate such as 214D is then as easy as Rodinal:
1. Measure 18 g/L (= 15.4 ml) concentrate into a beaker using syringe or scale.
2. Pour sulfite solution up to fill-line. This works out to 1+64 dilution.
For 214D, you would mix 46 g of sulfite into each litre of sulfite solution. If you wish, this can be stored refrigerated to ensure longevity. Quiz: Why 46 g/L instead of 45? Any idea how long sulfite solution will last?
Then I had the idea of doubling the sulfite (to 92 g/L) and adding some sodium metaborate to the sulfite solution, creating an alkali solution. If you then use 2.5 times as much concentrate, you should be able to make a close clone of XTOL similar to the formula I tested back in July here:
My latest alkali solution consists of:
Sodium sulfite ..................... 92 g
Sodium metaborate 4 mol .... 4.1 g
Water to ............................. 1 L
1L of developer contains 45 g of 214D (=38.6 ml) and the remainder is alkali solution (1+25 ratio of concentrate+alkali solution).
The pH matches XTOL perfectly, but the developer is too hot (overdevelops), so I need to reduce the metaborate in the solution some to get matching curves when using XTOL's times. Or maybe reduce the amount of concentrate. So I'll do more experiments. Anyway, if this works out, then 214D can be used either in its usual way or as an XTOL-clone.