Metol and Sodium Sulfite
I mixed a stock of D23 variant (5g Metol and 50g Sodium Sulfite) as a first bath for a two bath process. Since I'm experimenting I wanted to increase the Metol to 8g and wondered if adding more Metol will work since the mixing order, if I recall correctly, is significant in this case. If so is there a way around, such as first mixing a pinch of SS and the extra metol in 100ml then adding to the stock. Or shall I resign myself to mixing a new stock?
if you have problems mixing the extra 3g of metol you can mix up an extra 50ml with a pinch of sod. sulfite and add it to your 500ml. remember to account for the extra 50ml your A solution which will be 550ml. i've experimented with metol/sod. sulfite A baths and have found that there is a big difference between 6.25g/Litre and 7.5g/Litre solutions - the latter being more sensitive to temperature variations as an A bath ( B bath being 20g/Litre of sod. carbonate ). i imagine 8g of metol to be quite active and require repeatable temp control. good luck with your experiment and let us know what happens. i'll be very interested.
It's not that Metol is insoluble in sulfite solutions but it is slow to dissolve. Heat your solution to 125 F and then add the extra 3 grams. You may have to stir quit a bit but it will eventuaally go into solution.
Thanks, its good to hear that adding more Metol won't ruin the stock. Thanks for the heads-up about the temperature sensitivity. What I'm doing is a variation on Vestal Split D76, without HQ. 5g Metol, 50g Sod Sulfite bath 1 and 5 grams Borax, 50 g sod sulfite bath 2. I dubbed it D550. The first experiment I agitated continuously for 6 minutes each. Great highlight contraction about N-2 with nice highlight detail in the shadows for TriX@320. Lost about one-half stop film speed. So for 6 min split TriX would have been happier at 200 or 250.
I want to increase the activity so I can 1) agitate normally, 2) get an N dev time at a 6/6-10 minutes, and 3) get better zone I density at ASA 320. Basically achieve what I was getting for straight D23 at 12 minutes triX@320 in a two bath process with borax and see how it compares from a image and utility perspective.
may i direct you Barry Thornton's work on this kind of developer in 'Edge of Darkness'. he pinned the optimum level of metol at 6.5g/Litre for the two bath process. some food for thought as you experiment. cheers.
Thanks, I worked with Thorton's version for a few months. The activity was low as well, great for n-3 and n-2 development. The higher alkaline sodium metaborate may be a better substitute for borax in low action development. I agitated the Thorton D23 normally Decent ASA, 320 for TriX. I'm convinced that triX just isn't absorbing as much developer and needs more activity to get those great midtone/highlight separation I know is possible.
One observation regarding splitting 100g of Sodium Sulfite between A and B bath is the solvent action isn't as pronounced and looks more like Thorton's variation with 85g/liter sodium sulfite rather then straight D23 with 100g/l. I expected the solvent action to be the same as using 100g/l soduim sulfite as in D23 for the same development time. Splitting definitely affected the Sod sulfite's solvent effect on the grain in a way that is less flattering
i used to use metaborate as a B bath but concluded after testing that, unless i specifically wanted the fine grain look of metol 85g/L sod metaborate 12g/L, i prefered the look of sod carbonate 20g/L - total development in bath B. mid tones, to my eye, separate well ( by printing at grade 3 - 3.5 ) without the highlight being too problematic ( highlight gradiation is also maintained ).
what splitting has done is lowered the sulfite content, improving perceived sharpness. i never understood the benefit of having the extra 50g thrown in bath B. perhaps someone will chime in. if you like the look of sod sulfite 100g/L ( which suggests to me you want smooth tones at somewhat the expense of sharpness then pursuing max absorption at bath A and local development in bath B may be counter to that look?