My PC-512 Borax Developer

[Rlibersky]

Finally got through the thread. I am wondering if some, of the other experimenters, are willing to post some pictures here.

 

[JWMster]

Those shots came out REALLY nicely... to the extent that it makes me wonder about saving a buck with some Kentmere might not be such a compromise. Great work.

 

[relistan]

Finally got through the thread. I am wondering if some, of the other experimenters, are willing to post some pictures here.

@Andrew O'Neill has some on his video he linked earlier on

Those shots came out REALLY nicely... to the extent that it makes me wonder about saving a buck with some Kentmere might not be such a compromise. Great work.

Thank you! Yes, I have been pretty pleased with the Kentmere films, actually. I know they have lower silver content, but they have nice straight line response curves and the grain is pretty small for traditional grain films. In 120 the 400 has been very good for darker days here.

 

[JWMster]

Possibly you mentioned this in your linked article, but there's a Timothy Gordish who's linked to E-76: Phenodine = 20cc Sodium Sulfite = 100g , Vitamin C = 8g, and Borax = 12g. Not far off. Suggestion is to use D-76 times. Your formula has 3 development ingredients. Nice. This adds 1. I like that yours has long shelf life, too.

 

[JWMster]

BTW, here in the States, what we commonly call phenidone appears technically to be "Phenidone A" as I have just been schooled. ArtCraft sells it in 100g bottles for a good price. Haven't handled this before, and I'll have to look up the Hazards, but any special tips? I'm supposing the small size could be an issue, but health hazards? I'm assuming this is safer than Metol... which never bothered me, and gloves were sufficient for safety. From the E-76 formulation (which is embedded on this site somewhere) I see that discussion of it's components that "Hydroquinone" (in D76) is listed by EPA as an airborned carcinogen) substituted with Phenidone....which presumably is not since the formulation for E76 states that with Phenidone "it has none of this". Tim Layton's version of D76 used Metol instead, so this avoids that potential skin issue, too.

So all in, I take PC-512 to embody goals (not listed by the author in full perhaps) which I'll restate from reading through all this with intent to give it a whirl: 1) Safe, 2) XTOL-like tonality, 3) D76-like development, 4) One-bath, 5) Easy to mix and keep, and 6) Easy to put together 1-roll at a time without requiring 5 liters initial confecting of materials at the get go (like Ilford's ID11 seems to be). Thanks!

 

[koraks]

I'm assuming this is safer than Metol

Not necessarily. It's an irritant and toxic. The reason why phenidone-containing developers are often labeled as eco-friendly etc. is because they generally contain a relatively small amount of it. Phenidone powder should be handled with the same type of sane/sensible caution as other developing agents. Don't breathe the dust, avoid any contact with mucous membranes (eyes, nose, mouth), don't get it into your system, avoid skin contact.

Tim Layton's version of D76 used Metol instead, so this avoids that potential skin issue, too.

Phenidone can trigger contact dermatitis just like other developing agents. Again, the 'safety' of the compound derives mostly from the fact you need to handle much less of the compound in comparison to e.g. metol for the same quantity of an equally effective developer.

When in doubt, always refer to the safety data sheet.

 

[relistan]

Possibly you mentioned this in your linked article, but there's a Timothy Gordish who's linked to E-76: Phenodine = 20cc Sodium Sulfite = 100g , Vitamin C = 8g, and Borax = 12g. Not far off. Suggestion is to use D-76 times. Your formula has 3 development ingredients. Nice. This adds 1. I like that yours has long shelf life, too.

There are a number of developers that have 3-4 ingredients and which all have slightly different ratios. These ratios can produce a surprising array of different outputs. The main difference with E-76 is the large amount of sulfite. This is a kind of "magic" chemical in photo chemistry because it serves so many purposes. In D-76 and E-76 one of the main reasons to add it (other than as a preservative) is to aid in the dissolution of the edges of silver halide crystals and thus the exposure of additional latent image centers which may not otherwise be reachable. This is one of the reasons that most developers with sulfite are capable of producing a higher film speed than those without. However, that is only one mechanism and there are many others. In testing and including that of @aparat (now hidden, unfortunately), PC-512 Borax achieves box speed with the tested films so far. I expect that E-76 might produce higher film speed with the same films, but probably it will be less sharp. To me, the simplicity was one of the goals, as was the ability to work from a concentrate, so I am happy without the sulfite.

Not necessarily. It's an irritant and toxic. The reason why phenidone-containing developers are often labeled as eco-friendly etc. is because they generally contain a relatively small amount of it. Phenidone powder should be handled with the same type of sane/sensible caution as other developing agents. Don't breathe the dust, avoid any contact with mucous membranes (eyes, nose, mouth), don't get it into your system, avoid skin contact.



Phenidone can trigger contact dermatitis just like other developing agents. Again, the 'safety' of the compound derives mostly from the fact you need to handle much less of the compound in comparison to e.g. metol for the same quantity of an equally effective developer.

When in doubt, always refer to the safety data sheet.

Koraks is right here. The main reason that phenidone is much safer in developers like PC-512 Borax, is that there is just not very much of it!

 

[JWMster]

So.... have a set of chems on order from ArtCraft up in NY. Thought I had more of this on hand... but not. Still.... not bad on price.

 

[relistan]

So.... have a set of chems on order from ArtCraft up in NY. Thought I had more of this on hand... but not. Still.... not bad on price.

Look forward to your results!

 

[JWMster]

Look forward to your results!

Well here's a question I'm not sure about: You talk about mixing 300ML of combined - I'll be using different final quantity but that's not the question - and that Solution B is good for 3 to 4 films. I thought you were using this 1 shot. Ambiguity is a detail, but it helps to clear it away if possible. As a matter of reference, I'm using ID-11 one-shot and D23 pretty much the same as well. If you're running the same fluid a few times, then are you adjusting times for a 2nd, 3rd or 4th run?

 

[relistan]

Well here's a question I'm not sure about: You talk about mixing 300ML of combined - I'll be using different final quantity but that's not the question - and that Solution B is good for 3 to 4 films. I thought you were using this 1 shot. Ambiguity is a detail, but it helps to clear it away if possible. As a matter of reference, I'm using ID-11 one-shot and D23 pretty much the same as well. If you're running the same fluid a few times, then are you adjusting times for a 2nd, 3rd or 4th run?

It's all one shot, no re-use. In the blog post I make 1L of borax solution, which is good (one shot) for either three or four 35mm films depending on if your tank needs 250ml or 300ml.

 

[JWMster]

It's all one shot, no re-use.

Great! This helps a lot. THank you.

 

[Alan Johnson]

Where did you guys get your information about phenidone?
It appears to have been listed by the FDA as non-toxic. @6.07min.

 

[koraks]

Where did you guys get your information about phenidone?

Phenidone

Phenidone | C9H10N2O | CID 7090 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.

pubchem.ncbi.nlm.nih.gov

It appears to have been listed by the FDA as non-toxic

This is the only FDA listing I can find for it: https://precision.fda.gov/uniisearch/srs/unii/H0U5612P6K
They refer to four resources, one of which is the PubChem linked to above, which includes the toxicology information I relied on for my earlier post. I see no mention of it being non-toxic and I don't see how it could possibly be classified as such given the existing empirical evidence.

Unfortunately, even the Wikipedia entry for phenidone seems to be overly optimistic in stating it doesn't cause contact dermatitis (referring to a Merck publication that's closed access), although other sources are quite clear on the opposite, e.g.: https://haz-map.com/Agents/828 My personal experience is that phenidone most definitely is an irritant and I would be highly surprised if it would not be capable of triggering contact dermatitis. The dry powder should really be handled with gloves.

 

[Alan Johnson]

My point was really that phenidone appears to have a lower toxicity than metol for skin sensitisation which comes up as category 1. But it's a bit of a rabbit hole with hard to find comparative data.

 

[koraks]

Toxicity and skin sensitization are different things, though. I do agree that there are likely differences and that these are difficult to quantify. There can also be differences in personal sensitivity. It's complicated - as usual!

 

[relistan]

My point was really that phenidone appears to have a lower toxicity than metol for skin sensitisation which comes up as category 1. But it's a bit of a rabbit hole with hard to find comparative data.

I don’t have a lot of info, just that the safety data sheets list it as harmful to aquatic life and that it is a skin sensitizer. Both of which are much alleviated by such small quantities.

 

[bluechromis]

There are a number of developers that have 3-4 ingredients and which all have slightly different ratios. These ratios can produce a surprising array of different outputs. The main difference with E-76 is the large amount of sulfite. This is a kind of "magic" chemical in photo chemistry because it serves so many purposes. In D-76 and E-76 one of the main reasons to add it (other than as a preservative) is to aid in the dissolution of the edges of silver halide crystals and thus the exposure of additional latent image centers which may not otherwise be reachable. This is one of the reasons that most developers with sulfite are capable of producing a higher film speed than those without. However, that is only one mechanism and there are many others. In testing and including that of @aparat (now hidden, unfortunately), PC-512 Borax achieves box speed with the tested films so far. I expect that E-76 might produce higher film speed with the same films, but probably it will be less sharp. To me, the simplicity was one of the goals, as was the ability to work from a concentrate, so I am happy without the sulfite.



Koraks is right here. The main reason that phenidone is much safer in developers like PC-512 Borax, is that there is just not very much of it!

Some folks, including Gainer as well as Anchell and Troop, say there are advantages, such as sharpness, for developers that produce a greater degree of surface (chemical) development compared to those that create more physical development. Developers with considerable sulfite (AKA solvent developers) are said to create comparatively more physical development unless diluted. Ascorbate developers sans sulfite ought to promote surface development. I am curious if there is empirical evidence for the purported advantages of surface developers.

 

[JWMster]

FWIW, made up 200ML of Concentrate A and 2000ML of Concentrate B yesterday, and as a first time handling this, it took a while. Not in a bad way, but will hope the prep time shortens with familiarity. The 200ML of A pushes the Phenidone to 1 gram which is a tad easier to measure out... given it is VERY light weight stuff. Either way, however, I'm a tad leery whether I've got the exact number in the mix even though my scale measures to 2 decimal place....cause some sticks to the spoon, the side of the jar, goes airborne or otherwise AWOL, etc. And when you chief active ingredient is this small and apparently hard to handle, that seems dicier than it probably is. Yes, I'm not a chemist... but the imprecision of real world stuff and real world mixing means it'd be easy to be off .05 grams or more. But I have reasonably enough experience with other developers - commercial and home mixed - to hope that imprecision is fine.

But fairly, this of course means I'm trying to keep relatively low expectations for a 1st batch for HP5....and errors will likely all be my own in mixing rather than any fault of the formulation. That said, I'm pretty sure the NEXT batch will be a better controlled and more consistent batch almost to the extent of throwing this one out.... except I won't. It's likely fine. Mr. Transparency here.... my bad if that's TMI.

Times given for HP5 seem to run between 8 and 10.25 mins @20C. Delta 400 similarly has times of 8.28 and 9.12 min @ 20C. Some of these were given by others than Karl at 21C and converted back to 20C using the Massive Development Time/Temp converter. But as this sort of fuzziness suggests the merit of estimating time on the basis of the following steps I found either here or in a book somewhere (but seems a bit of arcana rarely discussed) so I'll be curious what times it actually gives and if it works - and frankly that might be a good way to correct for imprecise measurement, too... so this is a good thing to learn to do and on my bucket list anyway in terms of learning controls:

Film - Developer 1st Estimation of Time:
1) Clip a bit of film
2) Dip into the developer - NOTE the TEMP of the developer as the Defined TEMP
3) Time in seconds until the dipped part becomes dark is the TEST TIME for the Defined TEMP
4) Divide the TEST TIME by 3 and that's the recommended time at that temp
5) Repeat the above 2X to have a total of 3 times as a confirmed estimate

Going to go load the 2 rolls of HP5 I have as 1st guinea pigs ( tonight) for this into a tank and grab a 35mm roll I have somewhere unexposed to do some tests, too. I use a Citric Acid STOP and don't remember which FIXER I've got mixed - only that it works great. I've picked up an 8-inch tall McMaster distributed divided plastic gear box (with adjustable dividers - see photo) for holding the bottles like a Jobo would that I'm eager to try out as well for greater convenience and especially for some C41 and E6 temp controlled work I have ahead. Manufacturer sells this stuff in only large quantities, but McMaster will sell you only 1 and deliver it in 2-days which was amazing - and acce3pts returns without a prior authorization. If it works with my Cinestill temp control (Sous Vide) system, then it will be miles ahead of the Jobo CPE2+ I had as at 17-1/2" X 22-1/2" X 8" ( Part # 4893T29 ) BECAUSE there's acres of space to hold a lot of bottles ( I like to have a bottle made up for each chem bath and each rinse I use.... which can run 9 to 10 bottles for a full set) plus the Cinestill unit. I use 1 liter Nalgene bottles available from US Plastics which ain't cheap, but last and work extremely well.

As always, I'm eager for suggestions, corrections, etc. Thanks!

 

[relistan]

Either way, however, I'm a tad leery whether I've got the exact number in the mix even though my scale measures to 2 decimal place....cause some sticks to the spoon, the side of the jar, goes airborne or otherwise AWOL, etc. And when you chief active ingredient is this small and apparently hard to handle, that seems dicier than it probably is. Yes, I'm not a chemist... but the imprecision of real world stuff and real world mixing means it'd be easy to be off .05 grams or more. But I have reasonably enough experience with other developers - commercial and home mixed - to hope that imprecision is fine.

By the time you take that 0.05g of inaccuracy and divide it by 16-18 or more rolls of film, it makes almost no difference to development. Do your best to be accurate and then don't worry about the slight difference. You're going to be testing with the batch you made, anyway.

Times given for HP5 seem to run between 8 and 10.25 mins @20C. Delta 400 similarly has times of 8.28 and 9.12 min @ 20C. Some of these were given by others than Karl at 21C and converted back to 20C using the Massive Development Time/Temp converter. But as this sort of fuzziness suggests the merit of estimating time on the basis of the following steps I found either here or in a book somewhere (but seems a bit of arcana rarely discussed) so I'll be curious what times it actually gives and if it works - and frankly that might be a good way to correct for imprecise measurement, too... so this is a good thing to learn to do and on my bucket list anyway in terms of learning controls:

My starting times have been XTOL times minus 10 to 15% generally.

Film - Developer 1st Estimation of Time:
1) Clip a bit of film
2) Dip into the developer - NOTE the TEMP of the developer as the Defined TEMP
3) Time in seconds until the dipped part becomes dark is the TEST TIME for the Defined TEMP
4) Divide the TEST TIME by 3 and that's the recommended time at that temp
5) Repeat the above 2X to have a total of 3 times as a confirmed estimate

Feel free to try that and see how it goes. I just put a roll of 35mm into the camera, shoot 5 frames at different speeds (-2 stops, -1, box sped, +1, +2). Then I advance one more frame, cut it out of the camera, and develop to the time I think makes sense based on XTOL times. This usually gets me very close. You can see from the other more exposed or less exposed frames by how far you are off if you are off it at box speed.

Going to go load the 2 rolls of HP5 I have as 1st guinea pigs ( tonight) for this into a tank and grab a 35mm roll I have somewhere unexposed to do some tests, too. I use a Citric Acid STOP

I never use an acid stop bath with film, so keep in mind that my times will reflect a water stop of 1 minute.

As always, I'm eager for suggestions, corrections, etc. Thanks!

Good luck and let us know how it goes!

 

[JWMster]

Yeah. THanks Karl. Will let you know for sure. Thanks!

 

[Alan Johnson]

Test 1

I was thinking last night about @albada saying a few times that I should try metaborate in glycol. Referring to the solubility numbers I could find, it doesn't really pencil out as mentioned a few posts back. But I found some numbers for borax that showed that solubility might actually be higher in glycol than in water and I thought that might be even more true for metaborate. And then I was thinking last night that the solution will of course not be only glycol and metaborate: it will also contain ascorbic acid and phenidone. And actually that amount of acid could substantially change the solubility of sodium metaborate. So thanks to Mark (@albada) for mentioning it again. I did an experiment this morning (day off) and was able to get about a 50% solution of metaborate in glycol once the ascorbic acid was added. I tested the following:

• 6ml of propylene glycol
• 3g sodium metaborate
• 0.7g ascorbic acid
• 0.03g phenidone (from 2.5% glycol solution)
• Stirred and heated into solution

This translates to a full formula of (DO NOT USE):

• 100ml propylene glycol
• 50g sodium metaborate
• 11.67g ascorbic acid (target is 12)
• 0.5g phenidone

This turns out to actually be too much metaborate and the resulting pH is too high at about 9.25. Knowing this was too high, but wondering what effect that would have on times and density, I tested with a small strip of Ilford Delta 100 and backed the time down to 6 mins 15 secs at 20C. Resulting clip density was way too high at about 2.5 and those are unusable dev times for other films (e.g. Fomapan would be like 4 mins).

But it looks like there is a possible route there to a working developer.

Test 2

I did a further test to try to narrow in on the amount of metaborate needed to match the pH. I took 6ml of the PC-512 developing agents and added to 300ml of water. I then added small amounts of sodium metaborate and measured pH until I got to about 8.4. This is close to the borax version. I then tested a leader of Ilford Delta 100 for 6 mins 40s at 20C, the time I would normally use. I got a density of 2.10, which is just slightly under what I would normally get. I then developed a full roll in:

• 300ml water @ 20C
• 6ml PC-512 concentrate
• 1.2g sodium metaborate

Since the density was slightly low, I ran the short film clip for 7 mins. Results look pretty good. Eyeballing it I would say base + fog is a little higher, and maybe density a bit lower. Will post better numbers when the film is dried and I can measure it and scan it.

View attachment 332382

The idea then would be to try to make a single concentrate with that amount of metaborate. Assuming that it doesn't change its pH substantially when combining with glycol in heated solution.

I tried test 1 formula above with 20g/100ml as suggested by @relistan. Call it PCM20.

PCM20 one shot concentrate:

Propylene glycol ..............80ml
Sodium metaborate.........20g
Ascorbic Acid......................12g
Phenidone ...........................0.5g
Propylene glycol to....... 100 ml

It can be made in a container partly immersed in very hot water. The ingredients dissolve with stirring at 60C , with some effervescence around 50C.

For use dilute 1:50 with tapwater.

The viscosity is low and it is easy to syringe and mix.

Results of developing Fomapan 100 @ EI=100 for 4m, 6m and 12m 20C are attached.
Here is a test shot developed for 6m 20C:



I believe @albada found 15g/100ml metaborate in glycol was stable after 4 years [did not crystallise], here using 20g/100ml.
I did try the formula with only 12g/100ml metaborate but at 1:50 the negatives were extremely thin after 12 min development.

It seems that 20g/100ml is a good compromise.

Photoformulary and Fototechnik Suvatlar list sodium metaborate.

 

[Andrew O'Neill]

Great work, Alan. I'll have to give PCM20 a go.

 

[albada]

Alan, thank you for performing this experiment! I wanted to try modifying my Mocon developer like this, but eventually forgot about it. PCM20 is roughly the same formula as Mocon, but with no sulfite and about 1/4 as much ascorbic acid.

Mocon concentrate showed no deterioration (yellowing, or crystallisation, or separation) after years when kept frozen. At room temperature, it began yellowing after about six months.

However, in my article on Mocon, I mention that a major factor in crystallisation or separation is the ratio of metaborate to ascorbic acid. I found that a solution is stable for a ratio up to around 0.4 or 0.5. Above that, the concentrate collapsed after a week or two at room temperature. The ratio of PCM20 is 20/12 = 1.67, which is far above 0.5. On the plus side, the overall concentration is lower, so perhaps it will be stable. I suggest watching the room-temperature concentrate for a few weeks. Any crystals or smoke-like white wisps indicate failure. Even if it fails at room temperature, it might last a long time if kept frozen, so I suggest also keeping a bottle in the freezer.

Mark

 

[Alan Johnson]

Thanks Mark,
I will make up some more dilute in glycol as well as more PCM20.
The working solution (PCM20 1:50) has a pH of 9.15 +/- 0.05.