P-C-Soda and Fomapan 100: next step!

[eumenius]

Well, after I ruined two 120 rolls of Fomapan 100 in succession, the sacrifices apparently begun to work! In my last attempt I shoot the B/W step tablet with different ASA ratings, from 50 to 200. Development time was exactly 10 min at 20 C, 1st min constant agitation, then 10 sec agitation each following min. In those conditions the density was okay in frames shoot as ASA200, so probably the good development time for Fomapan 100 as ASA100 should be 8:30 - 9 minutes. I will post here when I will get results. This data should be applicable to all old-style films like Forte, Svema etc. Now I think if there is a way to decrease the speed of the developer - maybe glycerol in X-tol works like a diffusion brake? In present state the P-C-Soda requires a very precise timing and temperature control - 7:30 is not enough, and 10:00 is already one stop push!

 

[Claire Senft]

trying again to be helpful

I know that the first time I tried thise developer I used penidone in alcohol and got the type of results that you have gotten. I switched to metol and have had no further problems. If you have any metol try it. I know you feel differently but in the USA photographers are concerned with getting rid of 100 grams of Phenidone before it dies. I do understand that storage is important but 15 to 25 year old phenidone makes me suspicious of its strength. How much effort does it take to try meto; if you have it very little. No need to reply to this posting> I wish you luck and
Good negs
Claire

 

[Tom Hoskinson]

...in the USA photographers are concerned with getting rid of 100 grams of Phenidone before it dies. I do understand that storage is important but 15 to 25 year old phenidone makes me suspicious of its strength... Claire

I'll be glad to send you a sample of my 32 year old (dry) Phenidone. It is still fully active.

Phenidone deteriorates quickly in water. Alcohols are water grabbers and thus not the best preservatives for Phenidone .

Good preservative solvents for Phenidone are the various glycols, glycerine and triethanoamine (no water, of course).

By the way, I use Metol and Ascorbic Acid and I use Phenidone and Ascorbic Acid - - - they produce somewhat different results. I use triethanoamine (TEA) as the solvent.

 

[Maine-iac]

Well, after I ruined two 120 rolls of Fomapan 100 in succession, the sacrifices apparently begun to work! In my last attempt I shoot the B/W step tablet with different ASA ratings, from 50 to 200. Development time was exactly 10 min at 20 C, 1st min constant agitation, then 10 sec agitation each following min. In those conditions the density was okay in frames shoot as ASA200, so probably the good development time for Fomapan 100 as ASA100 should be 8:30 - 9 minutes. I will post here when I will get results. This data should be applicable to all old-style films like Forte, Svema etc. Now I think if there is a way to decrease the speed of the developer - maybe glycerol in X-tol works like a diffusion brake? In present state the P-C-Soda requires a very precise timing and temperature control - 7:30 is not enough, and 10:00 is already one stop push!

This is essentially the developer I use all the time. Here's a variation that may help when you're using different films.

I find that for Ilford Delta 400, (it may be the same for TMax 400 as well, though I haven't tested), the use of sodium metaborate instead of sodium carbonate will give development times in the 6-7 minute range.

However, for conventional films (not T-grain) as well as for ASA 100 T grain films like Ilford Delta 100 or Fuji ACROS, the use of carbonate gives times in the 7 minute range. Metaborate gives times with these films more in the 9-10 minute range.

Tom is right about powdered Phenidone keeping for a long time. I mix mine in 90% alcohol (because it's more convenient, more easily accessible, and cheaper) rather than in one of the glycols. I mix it only in 100ml batches, enough for 25 liters of developer, and have had no problem with it going bad or losing potency. I've kept it for up to six months with no discernible change.

If you're going to mix it in larger quantities and expect it to keep its properties for a longer time, then one of the glycols is probably a better choice.

Larry

 

[eumenius]

However, for conventional films (not T-grain) as well as for ASA 100 T grain films like Ilford Delta 100 or Fuji ACROS, the use of carbonate gives times in the 7 minute range. Metaborate gives times with these films more in the 9-10 minute range.

Hello Larry,
I tried to take metaborate (*4H20) instead of carbonate with my beloved Fomapan 100 - it works much slower, so maybe it's a good idea to give it a try - but the time for Foma with carbonate is still about 9-10 minute. Maybe Foma is just a tad special? I don't need a super-fine grain on my MF negs, the grain resulting from carbonate is okay... and it's not easy to find metaborate in Moscow, of course. I will try P-C-Soda on Acros and Ilford using your development times, I just don't use these films too often - they are too expensive for me and not readily available

Tom is right about powdered Phenidone keeping for a long time. I mix mine in 90% alcohol (because it's more convenient, more easily accessible, and cheaper) rather than in one of the glycols.

If Phenidone is dry and kept in a dark place, it should keep well. Only if it is dissolved once, it becomes oxidized and inactive very rapidly. Glycols are not the ideal solvents for it, too - they grab moisture from air, like all other alcohols, so it's easier to dissolve Phenidone in regular isopropylic alcohol (I'm a molecular biologist, so I have an access to it) and mix not more than 100 ml at one time. My experiments with Phenidone purification showed no difference between long-kept substance and fresh, new white crystals. Glycols are also too viscous to measure precisely, so the alcohols (or acetone, as it was commonly made in the USSR) are probably the best choice.

I have also a question about pH required for a correct work of Phenidone-ascorbate mix: maybe 10.6 is too much? Maybe it's better to use a different system, with another pH - a borate-based one, or even with some kind of organic base like tris-hydroxymethyl-aminomethane (pK about 8)? Is it important to keep pH constant during the development?

Regards, Zhenya

 

[gainer]

Zhenya, can you find borax and lye in Moscow? 69 grams of borax + 14.5 grams of lye when dissolved in water is close enough to 100 grams sodium metaborate 4 mol for government work. The pH may be modified up or down by changing the proportion of lye. Those amounts of borax (sodium borate decahydrate) and lye (sodium hydroxide) in a liter of water make a convenient solution equivalent to 10% sodium metaborate 4 mol. Incidentally, there is no difference between the 4 mol and the 8 mol in solution. The molecular weight of the 8 mol is exactly twice that of the 4 mol. One becomes the other above a certain temperature.
How much water can 100 ml of propylene glycol absorb from the air in a 100 ml container? You can dry the glycol by heat because it boils at a higher temperature than water. I have had better success with glycol than alcohols for this purpose. Beside the water, there must be oxygen in the solution to oxidize the phenidone. There will not be much of either water or oxygen in the airspace in a 100 ml bottle.

 

[eumenius]

Yes, both borax and sodium hydroxide are readily available in my lab, as well as a good pH meter to adjust the alkalinity. The final concentration of them in the developer will provide an adequate buffer capacity to keep the pH constant.

I am sure the glycol is a better solvent for Phenidone than hygroscopic primary alcohols, but it can be a problem to measure, say, 0.6 ml needed to fill my 300 ml tank. This problem can be easily overridden by use of a 1 ml positive displacement pipettor, like an insuline syringe, of course. One can think, however, that the nature of Phenidone solvent can influence some photographic emulsion properties like contrast, grain size etc, because it alters the adsorption properties of silver halide micellae - even when its concentration is low. I assume that the developer containing some surface-active isopropanol will work faster than its glycol analog, though it should be tested first

What do you think about pH optimum for conventional B/W development? Maybe some organic bases will work better than the inorganic ones? TRIS is very cheap, for example, has an excellent buffering capacity in pH 8-9 range...

Regards from Moscow,
Zhenya

 

[gainer]

First, make a weaker solution of phenidone so you can use more of it. Second, I haven't noticed any of the things you are worried about while using glycols as solvent. There is 25 or 50 times as much water as glycol, which at worst is only a small difference in dilution. I use triethanolamine as both alkali and solvent in some concentrates. Just dilute the concentrate with water and go at it. Other times, you may want to play with the pH, in which case the lye-borax mixture is convenient as part of a 2 part system. I often use the B part of PMK pyro as the B part of a PC-Glycol a part. This gives good control of activity, if I ever get enough practice to know how to use it.

I'm getting to the point where, if I want to get any picture taking done I will have to dump all but one of my developers and stick with that one. In fact, I did dump a lot of concentrates into 1 big jug of which I sometimes use a little for paper developer.

 

[Maine-iac]

I tried to take metaborate (*4H20) instead of carbonate with my beloved Fomapan 100 - it works much slower, so maybe it's a good idea to give it a try - but the time for Foma with carbonate is still about 9-10 minute. Maybe Foma is just a tad special? I don't need a super-fine grain on my MF negs, the grain resulting from carbonate is okay... and it's not easy to find metaborate in Moscow, of course. I will try P-C-Soda on Acros and Ilford using your development times, I just don't use these films too often - they are too expensive for me and not readily available

Every film reacts differently to a particular developer, I've found, so I'm not surprised that your times for Foma with either carbonate or metaborate are different than mine. It also depends on what enlarger, what paper, and what taste in final print contrast and look you want. I've never tried Foma, although I recently was given two 35mm rolls of it as a promotional gimmick at my local photo store. So, even though I haven't shot 35mm B&W for years, I may give it a try. Sorry that the Delta and Fuji films are so expensive in Moscow. I like them very much and have used them almost exclusively for years now.

If Phenidone is dry and kept in a dark place, it should keep well. Only if it is dissolved once, it becomes oxidized and inactive very rapidly. Glycols are not the ideal solvents for it, too - they grab moisture from air, like all other alcohols, so it's easier to dissolve Phenidone in regular isopropylic alcohol (I'm a molecular biologist, so I have an access to it) and mix not more than 100 ml at one time.

I'm neither a chemist nor a biologist, but I learned about using 90% isopropyle alcohol from Pat Gainer in the days before he began pushing ethylene and propylene glycol and trietholanomine. As he mentions in one of the responses to your post, sometimes it's possible to get too many developers going. I've stuck pretty much (except for a little fun experimenting) to the following formula which works very well for me, gives me very fine grain, very good sharpness, very good tonal scale.

5g metaborate or 6 g carbonate
4 g ascorbic acid
4 ml 1% Phenidone stock
1 liter water

I do the experimenting just for fun, but for my serious work, I stick with what I know and like.

I have also a question about pH required for a correct work of Phenidone-ascorbate mix: maybe 10.6 is too much? Maybe it's better to use a different system, with another pH - a borate-based one, or even with some kind of organic base like tris-hydroxymethyl-aminomethane (pK about 8)? Is it important to keep pH constant during the development?

The above formula with metaborate is usually around pH 10, although I don't have a pH meter--just indicator paper. So I can't be more precise than that. But around 10 seems to be close enough "for government work" as Pat Gainer is fond of saying. I've found that in photochemistry, that rubric serves well in most processes.

Off topic, we have some friends in Moscow. The husband is the chaplain for the American Protestant Chaplaincy and his wife, I believe, is doing something with refugees from Africa or something like that. Don't know whether she's with the U.N. or some private charitable agency, but we knew them from when they were serving the American Protestant Church in Bonn several years ago, and I was the pastor at the American Church in Paris. (The name "American" does not connote any ties to the American government; it's a common name for churches throughout Europe founded by Americans to provide a place of worship in English.)

Cheers,
Larry