E-72 Concentrate

[Maine-iac]

I tried something a little different yesterday and today with excellent results so far. Nothing terribly original, but promising in its benefits.

I mixed up a fresh batch of Chris Patton's E-72. Only I mixed it triple strength and left out the alkali (carbonate.) As you probably know, E-72 is similar in tonal quality and activity to Dektol (D-72) but made with Phenidone and Ascorbic Acid instead of Metol/Hydroquinone.

When I finished, I had a liter of triple strength E-72 (minus the carbonate) which had a pH of 5. I reason that at that pH, the concentrate should have excellent keeping properties.

Then, when I was ready to print, I mixed 100 ml of the concentrate with 900 ml of water, and threw directly into the tray two tablespoons of Arm&Hammer Washing Soda (carbonate). The carbonate dissolved in the tray in less than a minute with a little agitation and I was ready to print. The tray solution had a pH of 11.

I'm very pleased with the results. It's a neutral tone developer. The image appears in at least overall outline in 20 seconds, and full development is achieved in approximately a minute. In fact, after 1minute 20 seconds, no further development takes place.

Yesterday, I ran about six 11X14's and 10 8X10's through that liter of developer, and it showed no signs of slacking, so I saved it overnight and used it again today. No discoloration. Today, I ran 4 more 11X14's and another dozen or so 8X10's, and the only change I saw, was that for the last few prints, it was taking about 1 minute 20 seconds for full development. But the blacks were still deep and rich. I threw it out this time, figuring that enough's enough for one liter of developer, but I'm quite sure that I could have added another 25-50 ml of concentrate and another tablespoonful of carbonate and rejuvenated it if I had been doing a longer print run.

I don't know yet how long the concentrate will keep, but will report when I know. Might be six months for all I know.

Since I'm lucky if I get in the darkroom once a week, I wanted something that had good keeping properties, was non-toxic, and was easy to mix quickly. So far, so good.

Larry

 

[jim appleyard]

Cool! Sounds like the ascorbic acid version of Ansco 130.

 

[srs5694]

Since I'm lucky if I get in the darkroom once a week, I wanted something that had good keeping properties, was non-toxic, and was easy to mix quickly. So far, so good.

FWIW, I've used DS-14 in a replenished system with good results. I mixed up a liter of the developer and a liter of the replenisher (which is the developer minus potassium bromide). Each session, I'd pour my liter of developer into my tray, develop my prints, pour the developer back into the bottle, and top the bottle up with the replenisher. I used this for at least two or three months until I completely used up the replenisher. At that point the developer had darkened noticeably, but it still worked. To be on the safe side, I ditched it, and I decided to try out E-72, but once I've finished with that, I'll probably go back to DS-14. Although the DS-14 is a more complex formula than the E-72, the replenished use and long shelf life means it's at least as easy to mix and use over the long haul. I haven't attempted any computations, but I'm guessing the replenished use system makes DS-14 less expensive than E-72, although the DS-14 is more expensive on a per-liter basis for working-strength solution. DS-14, like E-72, is a PC developer, so no MQ allergy or toxicity worries. DS-14 takes a little longer to develop a print than E-72, though; I use 1:45 in DS-14 rather than 1:15 in E-72 (both times including drain time).

Edit: Oh, I forgot: I used Dimezone S rather than phenidone for both DS-14 and E-72. Suzuki specifies Dimezone S for DS-14, and it's possible that using phenidone would result in a developer that wouldn't last as long. On the other hand, it's also possible that E-72 lasts longer when made with Dimezone S. I know that mine keeps for at least a week or two at working strength, but I get nervous and ditch it after a while.

 

[Loose Gravel]

I hope this works out and I'm going to watch this post. I'm looking for a replacement to Agfa's Neutol +. Could this be it?

 

[Maine-iac]

FWIW, I've used DS-14

I tried DS-14 also and liked it. I think it's a fine developer.

I hadn't tried E-72 previously, and basically chose it to try because it's a very simple formula, and because I wanted to see if making it without the alkali added in until I'm ready to use it would give me solution that would keep a long time and could be mixed in concentrated form for easy dilution. I suspect it will keep because there's a lot of ascorbic acid (Vitamin C crystals) in relation to the amount of Phenidone, and the sulfite is also a preservative. I suspect it can be warmed up or cooled down by using EITHER potassium bromide OR benzotriazole as the restrainer. I use Edwal's liquid orthazite which is essentially benz, so I have a somewhat cooler tone. However, that was when my main paper was Afga MCC which with its warm base and cool-toned developer gave me lovely prints. Now that MCC is no more (except for several boxes I still have in stock) I'm starting to experiment more with Bergger and Kentmere, and both are cool/neutral emulsions. So I may switch to the bromide to warm them up a bit.

Since I've got enough Phenidone to last me my lifetime, I probably won't bother with Dimezone. I mix my Phenidone in 90% alcohol to make 1% stock solutions in 100 ml sizes, and it keeps just fine.

Larry

 

[srs5694]

I hope this works out and I'm going to watch this post. I'm looking for a replacement to Agfa's Neutol +. Could this be it?

A&O has announced that they'll continue to produce Agfa B&W chemistry. Most people have been concerned about Rodinal in this respect, so that's where the discussion has been focused. I don't know if this includes Neutol Plus, but it might.

Of course, there's nothing wrong with having a backup plan!