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Experiment with Jay DeFehr PG110B and DCM18/DCM20 developers

srardnec

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Luostari
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Moderator note: this thread was split off from another one: https://www.photrio.com/forum/threads/my-pc-512-borax-developer.195379


Hi, I found this formula in a search about phenidone-ascorbic acid developers. Sometimes I develop lot of whole-plate sheets and am interested in this kind of concentrates, often derived from Patrick Gainier tries.
I have been mixing a 12 y. old formula by Jay DeFeher https://flic.kr/gd/cXMbL :
PG110B
propylene glycol 100ml
borax 30g
scorbic acid 10g
phenidone 1g

as I read about these DCM20 and DCM18 formulas, and I have a lot of phenidone-B/Z ie. C10H12N2O CAS 2654-57-1, more active than phenidone-A, I went to mix DCM18. The idea being to use quite some of it, I mixed 200ml so 36g sodium metaborate, 24 ascorbic acid, 1,4 phenidone-B

I use a water-bath around 70°C and magnetic stirer.
With PG110B it takes some time but the borax then the ascorbic acid dissolve.
With this DCM18, sodium metaborate dissolves, it seem to reach point of saturation as a trace stays, neglieable, but then ascorbic acid didn't dissolve. After repeated long stirring and warmed a bit more around 90°C. The result is a creamy whitish emulsion, that decants after few hours, staying creamy, with glycol of course on top as it is light.

DCM18 vs. PG110B:





DCM18 decanted:





Anyway decided to try this. Shaked the small bottle well so to homogenize it. Used 2% solution with a sheet of old Agfa Mamoray (single-coated x-ray). Made 300ml, ie. 6ml seringed of this cream.

This is the developed sheet:



not printing to paper, went digital in order to have an idea. V700 scan at 2400 dpi and ColorPerfect inversion

800x JPG:



detail:




so this creamy stuff seams useable. Yet I prefer to obtain a soluted concentrate instead. Was expecting dissolution to be easier than in the case of borax.
 
Last edited by a moderator:

Please check the quality of your metaborate.
 
I already pointed out that the concentrates were found to be unstable and not a satisfactory replacement for the 2 part form of PC-512 Borax given in post 1.

My PC-512 Borax Developer

PCM20 [and probably HC-110] do not work with microfilm type films to give pictorial contrast, at least for practically useable EIs. I tried Spur Ultra R 800 at EI=10 in PCM20 for the dilution and times as specified in the massive development chart for HC-110 with Adox CMS20 but only obtained...
www.photrio.com
I suggest that if it is wished to further discuss the preparation and stability of such concentrates it might be better to start a new thread as it has been shown not to be relevant to the use of PC-512 Borax which is the subject of this thread.
 
Alan Johnson said:
I suggest that if it is wished to further discuss the preparation and stability of such concentrates it might be better to start a new thread
Click to expand...
Thanks for highlighting this; I've split off the post in question into a new thread.

@srardnec welcome to Photrio! Your example negative looks rather thin (underdeveloped) to me.
 
If all your chemicals are OK, it should dissolve if it is heated enough as others in that thread also found. But by Albada's rule for stability it is correctly predicted to crystallize eventually:

Progress on XTOL-concentrate

Mark; We typically used small strips (35mm x 12") to check new coatings and new chemicals out. Then we processed a full roll. I have never seen this happen. These were 1 L to 2 L tanks for the strips and about 2L - 4L for the full rolls. We used both hand agitation (dip and dunk) and...
www.photrio.com
 
I tried the PCM18 and 20 versions of PC-512 and now just have a bottle of Karl's original PC-512 on my darkroom shelf. The PCM versions just didn't work out for me. I wanted it to work in the worst way since I have a lifetime supply of Kodak Kodalk (8-mol sodium metaborate) to use up, but it wasn't meant to be.
I'll throw another something out there to chew on when it comes to sodium metaborate. I recently mixed a batch of PMK pyro and had a devil of a time trying to get the sodium metaborate in solution B to go into solution. I'm now wondering if my "older than the hills" Kodak Kodalk is the problem being 8-mol and being exposed to the atmosphere too long. I did buy some new Sodium Metaborate, but haven't tried to make a new part B for PMK with it yet. The Darkroom Cookbook doesn't seem to say it makes much difference whether the sodium metaborate is 4-mol or 8-mol when making fixers or whatever.
 
Sidd said:
Please check the quality of your metaborate.
Click to expand...

just regular sodium metaborate from Merck. Kept dry, etc. I use it trouble free mostly for DK-25R replenisher for D-23 (20g/liter) and in a Diafine ersatz (15g/liter).
How is the condition of sodium metaborate chimically tested?



]
 
Google Gemini:
Sodium metaborate tetrahydrate (NaBO₂ · 4H₂O) is stable at ordinary temperatures under normal storage conditions, but it is not stable when exposed to air for extended periods.
Ataman Kimya +1
Key factors affecting its stability in air include:
  • Carbon Dioxide (CO₂) Absorption: When exposed to the atmosphere for long durations, it readily reacts with CO₂ to form sodium carbonate and borax.
  • Humidity Sensitivity:
    • In a humid atmosphere, the tetrahydrate (4 mol) can pick up moisture and convert to the octahydrate (8 mol).
    • In a warm, dry atmosphere, it may slowly lose its waters of crystallisation.

I suggest try making up the part A of Mocon developer from @albada.It is documented on here that it was free of crystals.

Mocon -- XTOL-quality in a long-lasting concentrate

Mocon is a two-part developer consisting of a long lasting liquid concentrate and sodium sulfite powder used one-shot. It was originally intended to be an XTOL-clone, but it turned out to be not quite that. Mocon generally gives slightly finer...
www.photrio.com
 
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