That makes sense! I have used a lot of non-R XTOL and really like the developer. I have also developed with a lot of Diafine. But I still prefer one shot developers because I got through spurts of being very active and then not for awhile. I have had to throw out a lot of developer over the years because I let it sit too long.The reason I'm interested in PC-512 is that I would like to have a one-shot developer equal to Xtol-R with long keeping properties. I like and use Xtol-R a lot, but sometimes I just want to use a one-shot developer. It would be great to keep at my cottage instead of trying to lug Xtol-R up there.
I am pretty certain you can't dissolve all that borax. The reason I am using so much borax is because there is so much ascorbic acid. I added and mixed until I got to the pH I was looking for.
Have you tried using sodium metaborate instead of borax? They are both borates, so perhaps grain will look the same, but you'll probably need less of it -- enough less that you might get it to dissolve in the PG.
BTW, I read that Kodak replaced the sodium metaborate with borax in XTOL a few years ago to save money. That's a clue that they are interchangeable (but different amounts).
Have you tried using sodium metaborate instead of borax? They are both borates, so perhaps grain will look the same, but you'll probably need less of it -- enough less that you might get it to dissolve in the PG.
BTW, I read that Kodak replaced the sodium metaborate with borax in XTOL a few years ago to save money. That's a clue that they are interchangeable (but different amounts).
Mark,
I was thinking along those lines too. It would be nice to get the Kodalk (sodium metaborate)to be able to go into the glycol. For me, a slight increase in grain from the switch to Kodalk wouldn't be much of a problem, since I very seldom shoot formats under 6X6.
.........BTW, I read that Kodak replaced the sodium metaborate with borax in XTOL a few years ago to save money. That's a clue that they are interchangeable (but different amounts).
When creating Mocon, I discovered that a seemingly unlimited quantity of Kodalk and ascorbic acid will dissolve into PG. That's because it's not simple dissolution; rather, the chemicals are combining in some way. After dissolving everything, one is left proudly holding a beaker of beautiful clear solution. But after a day or two, one might notice a white wisp forming in the solution. And it thickens, and eventually takes over the entire solution, which separates into two liquids. What happened is that the solution was unstable, and one or more components left the main solution and separated into its own liquid of some kind. In my Mocon article, I describe some apparent conditions under which this separation occurs. That's worth reading.
The separated solution might develop film fine, if you shook it first to mix the separated liquids. I don't know; I never tried it. But if it's a good developer, then I think it would be acceptable to require that the concentrate be shaken before use.
And the difference in pH could be corrected by a little sodium hydroxide which is very cheap. But I don't know about solubility in glycol.
As an aside, I wondered why my 510-Pyro was giving poor shadow speed. I had mixed it without heat, which took days to dissolve. Now I wonder if it actually relies on being cooked a bit which is what is recommended and maybe that causes some reactions, not just dissolving.
Would boric acid and Borax be interchangeable w/ the developer? They sell Borax in the 20 Mule Team detergent, which is for washing clothes. I went to the detergent's website and they list only Borax, oxygen and sodium (the last two seem to be already in the Borax anyway). They mention that Borax is considered a salt, and shares many chemical properties with table salt.
Borax apparently is the mineral that comes right out of the ground, while boric acid is the mineral in a processed form.
Borax apparently is the mineral that comes right out of the ground, while boric acid is the mineral in a processed form.
Boric Acid is the free acid H3BO3 with one easily detached proton H3BO3.<===> H3O+ + BO2-. Sodium Metaborate is the sodium salt of this acid: NaBO2 with different amounts of crystal water tied to it.
Borax is a mixed crystal of Boric Acid and Sodium Metaborate, so it's moderately alkaline. All three salts will dissolve in PG, which allows you to set the target pH in a wide range from acidic all the way up to quite alkaline.
Stick another one on the list! It's like my never ending pile of negatives!
If I could get box speed with dilute Perceptol I'd use that for almost everything and Pyrocat for the rest.
Hmm, it seems in Europe I cannot buy powdered metaborate. I can make it of course, but it would be in a water solution (AFAICT NaOH is not soluble in glycol). Since I don't want water in the concentrate, I could evaporate it down to powder, but it all sounds like a lot more work than I want to put into it. I have a small amount of powdered metaborate from the US so I may try it once with that, but that would be all I have.
I can make it of course, but it would be in a water solution (AFAICT NaOH is not soluble in glycol).
John, Perceptol and attaining box speed does seem to be a bit of a mystery. According to Ilford you get box speed in the Delta range with Deltas 100 and D3200 at 3200 but not quite in D400. In the lower speed ones such as Pan F and FP4 you get it also but fail slightly in D400 and HP5
You also get it in Acros and both the 100 and 400 TMax. Oh, and the former Neopan 400 makes box speed as well No times or speeds for P3200 or Tri-X
I have yet to see a pattern that explains why some 400s make it and others don't. Of course that doesn't mean that Perceptol gets you there in your personal tests. However Perceptol seems a strange beast when it comes to speeds
pentaxuser
This post by @Nikola Dulgiarov gives a simple procedure for synthesising Metaborate crystals. I've used the process and found that it works well. You may want to give it a try.
From what I see here, PC-512 might be a long-lasting replacement for Perceptol in my chemical cabinet. Sharp enough, soft-working with a good range of tones while not going over the top in the highlight area. Yes, I will play with this when I get back home to that chemical cabinet.
Hmm, it seems in Europe I cannot buy powdered metaborate. I can make it of course, but it would be in a water solution (AFAICT NaOH is not soluble in glycol). Since I don't want water in the concentrate, I could evaporate it down to powder, but it all sounds like a lot more work than I want to put into it. I have a small amount of powdered metaborate from the US so I may try it once with that, but that would be all I have.
Thanks Alan, glad you approve of the work. Yes this is not a solvent developer. It does produce quite fine grain, though, at least on the films I've used. I will put something quite grainy through it when I get a chance. I have some ORWO N75 that I usually used in XTOL.Xtol, Perceptol etc give fine grain because the sulfite is a solvent and redeposits finely divided silver on the emulsion.
I don't see anything here with a similar solvent action so the grain is unlikely to be so fine.
However, the pH is quite low so the grain is likely to be finer than with eg PC-TEA.
Also, sulfite, where present, uncovers latent image sites giving higher film speed than where it is left out.
But IMO it would be hard to devise much of an improvement on the OP's formula when no sulfite is used.
As I mentioned above, I'm a medium and large format guy mostly. While I'm not a grain worshiper, I'm certainly not against seeing “honest” grain. I would much rather see that "honest” grain than mushy grain. It will still be interesting to see what I think of Xtol-R compared to a non-sulfite developer like PC-512 or even Mark's Mocon.
Fototechnik Suvatlar has it and ships world wide. It's on his current 2022 price list.
This post by @Nikola Dulgiarov gives a simple procedure for synthesising Metaborate crystals. I've used the process and found that it works well. You may want to give it a try.
This is from the roll I just developed, showing some different lighting conditions than the others I posted.
Leica M2 with Summarit-M 2.5/35mm on Ilford Delta 100 at box speed. PC-512 Borax 1+50 for 6.75 mins at 20C.
View attachment 322102
Dmin on this roll was 0.38 and Dmax was 2.26
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