Replenish Mytol?

Donald Qualls · Jun 11, 2020

I searched on this, and found one mention of actually using Mytol replenished -- in a rebuilt C-41 processing machine, a post in 2012 asking about pH changes and loss of speed in replenishment (and treating it as identical to Xtol).

I'm interested in setting up to replenish, and Xtol looks like the easy way, since it is its own replenisher. I've seen the Naked Photographer on YouTube calculate a long term cost of around 14 cents a roll for replenished Xtol -- but I can easily beat that with one-shot Parodinal. Yes, very different developer, very different negative character.

It seems very probable, however, that I can mix Mytol at a fraction of the cost of buying Xtol -- and since I have reverse osmosis de-ionized water to mix with, I'm not worried about the effects of water (and leaving out the Calgon and similar).

So the question here is: does Mytol actually work well (like Xtol) in a self-replenished regimen, and is the replenishment rate the same if it does?

Raghu Kuvempunagar · Jun 11, 2020

Donald,

If you are thinking of a replenished developer that you can mix yourself, you might want to consider Adox MQ Borax.

Donald Qualls · Jun 11, 2020

Thanks, Raghu -- if it were only that, I'd go with D23 and its replenisher, DK23R; I used (home mixed) replenished D23 for most of a year back in the 2004-2006 time frame. I'm specifically after the properties of Xtol (sharpness, full or slightly increased film speed) along with the cost saving of replenishment and home mixing.

If I can't verify Mytol works well in replenishment, I'll probably mix up a big enough batch to treat as Xtol, and watch the first few rolls closely. Xtol is said to take four to six rolls to reach equilibrium in replenishment, and then requires a little more time than fresh stock, so it ought not to be difficult to see this happening with Mytol -- or not happening.

If Mytol misbehaves in the first 6-8 rolls, there'll still be plenty to use up as one-shot with dilution, so little if any waste.

MattKing · Jun 11, 2020

The biggest challenge will be determining whether the rate of build up of development byproducts matches the rate of decrease of chemical capacity.
If not, you may not see any mis-behaviour until later than 6-8 rolls.
The big advantage of X-Tol is that those two rates are matched, thus permitting use of fresh developer as replenisher, rather than needing a separate and different replenisher.
Good luck and I will be interested in your results.

Donald Qualls · Jun 11, 2020

MattKing said:
The biggest challenge will be determining whether the rate of build up of development byproducts matches the rate of decrease of chemical capacity.
If not, you may not see any mis-behaviour until later than 6-8 rolls.
The big advantage of X-Tol is that those two rates are matched, thus permitting use of fresh developer as replenisher, rather than needing a separate and different replenisher.
Good luck and I will be interested in your results.

Mytol is supposed to be a direct replacement for Xtol -- but it's not as simple as Parodinal replacing Rodinal in one-shot processing, of course. We can be fairly confident on the sulfite level, and we know Xtol is a PC formula with not much if anything else in the fresh stock other than the borax accelerator -- and a hint of restrainer, as I recall (don't have the Mytol formula in reach while I'm typing this).

I guess the question is how much risk with my film am I willing to take to save, perhaps, five or six cents a roll over long-term Xtol replenishment (and thinking of it that way, the answer may be "none"). Hence why I'm here asking -- apparently at least one person was doing it in 2012, but they were here asking questions about a sudden excursion that turned out to be pH related, and the thread was too long to immediately determine if it was a developer limitation or something related to the automatic processor he was using.

koraks · Jun 11, 2020

Donald Qualls said:
and a hint of restrainer,

Nope, that that I'm aware of. Mine is just sulfite, phenidone and vitamin c with an activator, for which I use borax + sodium carbonate. No bromide or benzotriazole. A replenished variant would build up bromide and perhaps trace amounts of iodide depending on the film processed - among all sorts of other stuff such as oxidized developers, maybe some minute traces of certain sensitizing metals such as iridium.

I don't know if a replenished mytol will work and if so, under what conditions. I'd start by doing some longevity tests on non-replenished mytol and compare that to genuine Kodak xtol to see how comparable they are in terms of stability.

Donald Qualls · Jun 11, 2020

koraks said:
Nope, that that I'm aware of. Mine is just sulfite, phenidone and vitamin c with an activator, for which I use borax + sodium carbonate. No bromide or benzotriazole. A replenished variant would build up bromide and perhaps trace amounts of iodide depending on the film processed - among all sorts of other stuff such as oxidized developers, maybe some minute traces of certain sensitizing metals such as iridium.

I don't know if a replenished mytol will work and if so, under what conditions. I'd start by doing some longevity tests on non-replenished mytol and compare that to genuine Kodak xtol to see how comparable they are in terms of stability.

That sounds like a sensible approach -- I should be able to make my scanner pretend to be a densitometer, at least well enough to spot negatives that have lost contrast relative to a reference. I see two possible approaches -- either add time for each processed roll, as if I were reusing Xtol stock according to Kodak instructions, or don't add time and observe how rapidly contrast drops off. The former at least has canonical data to work against (I think). Or are you talking about storing the stock solution (I can get one liter PET bottles for 79 cents -- and dump the seltzer water that comes in them) and watching for deterioration over time?

koraks · Jun 12, 2020

Donald Qualls said:
don't add time and observe how rapidly contrast drops off.

Yeah, that's the approach I had in mind. But it's a bit of a napkin exercise to be honest; I never really seriously considered working out a thorough approach towards replenished mytol. Personally I just use it one shot or perhaps twice, but discard after a couple of days. I always considered mytol a bit too cheap to make things complicated.

Raghu Kuvempunagar · Jun 12, 2020

Donald Qualls said:
I'm specifically after the properties of Xtol (sharpness, full or slightly increased film speed) along with the cost saving of replenishment and home mixing.

How're you going to ensure that the stock/replenisher don't go bad due to Fenton reaction?

@albada developed a glycol based alternative to XTol which might be a better choice for single use.

Donald Qualls · Jun 12, 2020

Raghu Kuvempunagar said:
How're you going to ensure that the stock/replenisher don't go bad due to Fenton reaction?

I use RODI purified water (purer than most distilled, and handled only in aquarium grade plastic after purification) to mix chemicals. All my storage containers are either bought-new photographic items, or food-grade PET bottles. The only reasonable source for iron ions would be the stem of my darkroom thermometer (which is stainless, but not coated with glass, plastic, etc.) This could possibly affect the working solution, but not the stored replenishment stock (no reason to ever check or regulate its temperature).

138S · Jun 12, 2020

Donald Qualls said:
I searched on this, and found one mention of actually using Mytol replenished -- in a rebuilt C-41 processing machine, a post in 2012 asking about pH changes and loss of speed in replenishment (and treating it as identical to Xtol).

This is easy to check, just develop lights open in a small tray some fully exposed film ends, with some ml of developer, using the little amount of starter and replenisher that is proportional to the film film test strip size.

I guess that while it would work the same perhaps the shelf life of the used developer may be different, so I think this is what it would be important to check.

Raghu Kuvempunagar · Jun 12, 2020

Isn't possible to test whether Mytol is its own replenisher in a systematic way? The only parameter that needs to be determined is the replenishment rate. We can have, say, five bottles of replenished working solution where each bottle is replenished with a volume specific to that bottle - 50ml, 100ml, 150ml, 200ml and 250ml after developing a full roll of 35mm film with that bottle. Results can be evaluated at the end of every round of development.

koraks · Jun 12, 2020

There's no doubt that mytol can work as its own replenisher. The question is if it is workable in a practical setting where there may be long intervals between development and replenishment sessions.

138S · Jun 12, 2020

Raghu Kuvempunagar said:
The only parameter that needs to be determined is the replenishment rate.

IMO the formal replenishing rate does not exist, it depends on how dense are our negatives. If we usualy meter to expose average +1 then we'll need more replenising rate because we exhaust more the developer from our denser negatives. So we may end making drop tests to know how strong our soup remains, before it's noticed in the negatives.

Xtol replenisment is not the usual way. A classing replenisment consists in a bromide rich stater and a low bromide replenishment, in that way the replenisment overflow removes the average bromide produced in a development, in this way Br is kept stable from the beginning to the end.

Instead Xtol replenisment relies in a high replenishment dose that saves only one third of the chem, this is quite useful when our tank requires too much undiluted stock liquid so we waste a lot of chem but in a rotary Xtol replenishment is not to save much chem.

koraks said:
There's no doubt that mytol can work as its own replenisher. The question is if it is workable in a practical setting where there may be long intervals between development and replenishment sessions.

+1

Raghu Kuvempunagar · Jun 12, 2020

koraks said:
The question is if it is workable in a practical setting where there may be long intervals between development and replenishment sessions.

Doesn't replenished XTol work fine in such situations? The solution could be in replenishing with slightly larger volume of replenisher than one would do normally. It might be the same case with MyTol. Of course only experiments can confirm.

koraks · Jun 12, 2020

Raghu Kuvempunagar said:
Doesn't replenished XTol work fine in such situations? The solution could be in replenishing with slightly larger volume of replenisher than one would do normally.

Yes, but this is about mytol. Since XTOL is a proprietary formula, it is not certain if mytol will behave similarly especially taking into account the practical reality of long intervals between replenishment.

Raghu Kuvempunagar · Jun 12, 2020

koraks said:
Yes, but this is about mytol. Since XTOL is a proprietary formula, it is not certain if mytol will behave similarly especially taking into account the practical reality of long intervals between replenishment.

I don't know how @Donald Qualls plans to use replenished MyTol. It's possible that he will pool a good number of exposed rolls and develop them in quick succession using the replenished developer. That way he can get good economy while not needing long shelf life.

koraks · Jun 12, 2020

I really thought this was specifically about mytol, not xtol.
In any case: yes, you could develop in rapid succession and then discard the developer, but in my view that would limit the purpose of replenishment to its supposedly unique image characteristics. I can't comment on those as I don't know what they are and haven't seen them myself (but, I haven't tried!)

Donald Qualls · Jun 12, 2020

138S said:
Xtol replenisment relies in a high replenishment dose that saves only one third of the chem, this is quite useful when our tank requires too much undiluted stock liquid so we waste a lot of chem but in a rotary Xtol replenishment is not to save much chem.

I don't consider 70 ml a roll a high replenishment dose. Where are you getting that impression?

My current expectation is to develop a couple rolls a week -- at least until I get caught up on film that's been waiting a while. Longer term, it'll be at least a couple rolls a month. No pooling up to develop 20 rolls in a weekend -- I use plastic reels a lot, and they have to be dry. I do have stainless for 35mm, but never got really comfortable loading those with 120.

138S · Jun 12, 2020

Donald Qualls said:
I don't consider 70 ml a roll a high replenishment dose. Where are you getting that impression?

Xtol 70ml dose is a high replenishment dose, D-76R dose is 22 to 30ml.

With Xtol you replace 70ml when for single shot you only require 100ml.

I don't say that because of the economic cost, but for the chemical concentration strategy each kind or replenishment uses. In the Xtol case you never discard the liquid in the tank as you replenish indefinitely, this is possible because of the high dose, with D-76 you have to discard the liquid in the tank after some amount of film processed.

m00dawg · Mar 5, 2021

@Donald Qualls curious as to if you were able to try replenishment and what those results were?

Donald Qualls · Mar 5, 2021

@m00dawg I've been running my Xtol replenished since last September; I've used a liter or so of replenisher so far, got a couple liters left (my tank solution is two liters because my Yankee Agitank needs almost 1.6 liters to cover 4x5 film). If Kodak Alaris/Sino Promise will get their act together, I'll be mixing more in a few months. So far, it's working great, even though I'm averaging no more than about a roll a week.

I'm also replenishing Flexicolor LORR color developer, on which I was also warned about my low volume (similar, average about a roll a week); that uses a little less than half the replenishment rate of Xtol (roundly 30 ml per roll, depending on the film stock) and that's going well too. As usual, manufacturer recommendations are well onto the conservative side.

And years ago, I mixed D-23 and DK-25R, and ran that replenished for a few months (before deciding I didn't like the mushy-grain look of D-23 that much).

I never did mix Mytol; apparently, in order to make it reliably last long enough to bother with replenishment, one needs to source high purity, iron- and copper-free chemicals, which pushes the cost up significantly.

m00dawg · Mar 5, 2021

Donald Qualls said:
[I never did mix Mytol; apparently, in order to make it reliably last long enough to bother with replenishment, one needs to source high purity, iron- and copper-free chemicals, which pushes the cost up significantly.

Ah got it! Yeah I was wondering since, I too, have been loving XTOL-R, actually largely for the R. Folks find that a drawback but I find it hugely beneficial since I can do sheets without wasting chemicals and I generally really don't like having to mix chemicals (and like that, when I do, I can do them in large 5L batches). Buuuut given the XTOL situation, I'm starting to shop around as it were. I didn't think about the purity issue with Mytol so that's good to know. Guess I should keep looking, although mixing it up one-shot doesn't seem so bad in reading through this thread (though ignores my favorite feature of real XTOL alas).

I haven't tried replenishing Flexicolor C-41 but awesome you have that working! I do use Flexi but been using that one-shot. My primary concern has been finding a better way to store the stock fixer and how far I can push the bleach. I know you can aerate it and check/adjust pH, but I recall there was something else about bleach you have to do ideally (I can't remember what it is, and will have to re-read some old PE posts probably to find it again).

Donald Qualls · Mar 5, 2021

I just mixed fresh C-41 fixer due to a bottle crossup that landed 300 ml of my developer tank solution in the fixer bottle. Before that, after 20+ rolls, that liters of fixer (I apparently ordered RA instead of LORR on the fixer) still had a clearing time well under a minute. My bleach is the same age, and hasn't shown any indication of weakening (it does get a little aeration every time I pour it back into the storage bottle). My plan has been to replace the bleach after processing 32 rolls in the liter, or at the first sign of unintentional silver retention.

relistan · Mar 7, 2021

Hey Donald AFAIK Mytol is an XTOL work alike but not super close to the original formula. I am looking for the doc but somewhere I found a comparison to the XTOL patent. That’s not to say it won’t just work in replenishment in the same way. It might. Mytol has less sulfite as far as I recall. From memory I believe XTOL also has EDTA as a chelating agent, which also has silver solvency properties (so says Haist). The long and short of it is Mytol is a different developer so would need long term testing. I’d love to know how it turns it if you do it, though!

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