My PC-512 Borax Developer

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relistan

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Thanks for testing that @Alan Johnson. Results look good. It’s interesting that the pH is over 9. I wonder if something like 18g would result in closer to the pH of PC-512 Borax? In any case this is great. Thanks!
 

Alan Johnson

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In case PCM20 should crystallise I made up a half strength concentrate PCM10 for storage [pic]:

PCM10 one shot concentrate:

Propylene glycol........................80ml
Sodium metaborate..................10g
Ascorbic acid.................................6g
Phenidone....................................0.25g
Propylene glycol to.................100ml

For use dilute 1:25 with tapwater.

Here is a test shot developed for 6m 20C in PCM10 1:25 [underdeveloped, dull day]


I guess a small decrease in metaborate in PCM20 might increase the developing time without detectably reducing the grain so will keep to the PCM20 formula.
 

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JWMster

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Alan: Please forgive me as I'm sure this was covered, but having done the PC-512B mix and liked it and NOT really seeking to re-read a zillion posts on this thread, can you please tell me what the effect is in replacing the Borax with Metaborate? Is there a particular effect on accutance or grain, or is the substitution driven by what's on hand (and/or available) and what's not?
 
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Alan Johnson

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The PC 512 concentrate is mixed with a borax solution.
The PCM20 metaborate concentrate is mixed with tapwater.
Whichever is considered more convenient.
The working solutions are not the same and cannot be made so.
I am not planning a comparison but it would be no surprise if they have very similar grain etc.
 
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relistan

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Alan is carrying on from the experiments I did toward a single solution. Some people really want a single concentrate and the only way to do that with a borate is with metaborate since it has so much higher solubility in propylene glycol than borax does. His concentrates use the same ratio of ascorbic acid to phenidone that I worked out, but the pH is different because sodium metaborate has a higher pH in solution than borax does. This may or may not have an effect on grain. It definitely changes the development times.
 

Alan Johnson

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Using Ilford Delta 100 I compared HC-110 1+47 (dilution E):

with PCM20 1:50:

Both were developed for 7.5min 20C, a little too long for PCM20.

As far as I can see from these scans , the grain is similar for both but PCM20 seems to have an edge for apparent sharpness [they were processed virtually identically). So far so good for PCM20.
 
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JWMster

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Karl and Alan: Can you speak to the keeping qualities? While taking a break to develop some color, I need to mix some more PC512B, and notice that Concentrate-A with the glycol is now a bit yellowed (which I assume is just the glycol's color). I believe you'd mentioned it will keep and remain effective for more than a year or so. Am I confused on this? Probably too early to ask about Alan's version PCM20.... but did want to say "very nice results!" on the small jpeg posted here. THanks!
 

Alan Johnson

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@JWMster, Karl is busy so I will have a go re your question.
The 512 concentrate in 100 propylene glycol contains 0.5g phenidone and 12g ascorbic acid (post 1 link).
This is somewhat similar to Gainer's PC glycol from some years back and I never saw any grumbles about the stability of that.
So it appears that PC512 concentrate should also be long lasting.


btw, click on my Flickr pics here to get an enlarged version.
 
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JWMster

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Alan: Kind of you to reply. Thanks! I'm kind of assuming the yellow colorization is fine anyway. Thanks.
 
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relistan

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Looks good, Alan.

Karl
 

JWMster

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Alan: Foreground detail (water) looks comparable. Both are great shots. Same day? Same camera? What format? BTW, really like the shot from # 302 above, but about 50% less diluted. If I may, what inspired the change? aka... what were you trying here as opposed to #302? I'm about to mix some PC512B, but I do have some Metaborate... might not do it this go round, but eventually I've got to use that stuff or throw it out.
 

Alan Johnson

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Hello JW,
Pics are of places easy to get to for me, all are on 35 mm with my Ricoh FF-70 (5 element lens). Regent Street was on Fomapan 100. The boats were on Ilford Delta 100 ,rather hazy because of light autumn rain which may account for the difference in appearance. Traditional and tabular grain films, the latter being a little sharper.
I stocked up with metaborate when heard it was to be generally discontinued and has to be bought from photo chemical suppliers so not many will bother with that version I daresay.
Hope you will post some pics here later.
 

JWMster

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Alan: Thanks. Great detail. I should have been more specific in my inquiry regarding the switch in dilution from 1:25 to 1:49 with PCM20. Was it simply to match the HC-110 Dilution E's dilution?
 

Alan Johnson

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The 1:25 dilution is for PCM10 which contains the same ingredients as PCM20 but at half the strength.
So the working solutions from PCM10 1:25 and PCM20 at 1:50 are identical except the PCM10 will have a tiny bit more glycol.

PCM20 1:50 is the one I expect to use, PCM10 1:25 is for storage in case the PCM20 crystallises.
I used PCM10 in post 302 just to confirm that it works.
The difference in tonality in post 306 is the result of there being light rain on that dull day.
I used HC-110 1+47 as being a close match for PCM20 1+49, to compare the two.
 

JWMster

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Alan: PERFECT! Now my old thickhead understands. Thank you.
 

Alan Johnson

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After 6 weeks the color of PCM20 concentrate had a yellow tinge [attachment].
These two illustrated are kept for a shelf life study with occasional opening of the caps to let air in.
The separate sample I use continues to give satisfactory results, eg:

 

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albada

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Alan, are you keeping some PCM20 refrigerated or frozen? Based on my experience with Mocon, it'll probably last much longer.

Mark
 

Alan Johnson

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Thanks for the comments, on consideration some changes to the concentrate.
(1) 0.5g phenidone to be replaced by 0.7g dimezone-s (0.5 x (206.2/162.20)) +10%, post 146, @john_s.
This because the presence of metaborate may produce alkaline conditions from the water of crystallization.
(2) The metaborate to be reduced so as to give a development time approximately the same as HC-110 1+47.
This to allow times for many films to be estimated from the massive development chart.
(3) A sample of the changed concentrate to be fridge stored.
For actual use a different sample of changed concentrate to be kept at room temperature in a glass bottle, ie, used in the same way as HC-110 [new water solution] and Ilfotec HC.
I hope to post an updated concentrate formula later.
 
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John Wiegerink

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Alan,
I've been closely following your experiments, since using Kodalk (sodium metaborate) is more to my liking. Plus, I have several pounds of Kodalk and this developer would be a good place to use it. Your results look very good to me and well worth the effort.
 

lamerko

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Interesting topic. I plan to try the metaborate formula. I would replace Phenidone A with Phenidone B (Methylphenidone). Methylphenidone oxidizes more slowly, and unlike Phenidone A, it comes in microgranules or crystals (I'm not too sure). It is easily measured, non-volatile and does not stick to dishes and paper. It is much easier to work with it.
About Metaborate - I have some stock but have been wanting to try making my own for quite some time, just to know I would have a reliable source for the future. The method is straightforward:
"69.15 g of borax (decahydrate) and 15.20 g of sodium hydroxide (purity 99%, 5% excess) were mixed in a plastic beaker as dry powders and 17.0 ml of ice-cold DI water (5% excess)"
Click to expand...
I have a query here for those who have tried this way. I have sodium hydroxide in granules and flakes. The flaked one probably won't be good because the flaked ones are quite large. Do I need to grind/pulverize the granules or can they be used directly in the mixture? I guess the high hygroscopicity might not allow me to get powder from the granules...
 

koraks

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What physical form the NaOH comes in is inconsequential as long as you can sufficiently accurately measure it. Once in solution, it really doesn't matter if it started out as flakes, granules, powder, etc.
Dealing with powdered NaOH is literally irritating since it will quite literally dissolve your mucous membranes if it gets airborne. I guess that's why it's generally distributed in a more granular form.
 

Alan Johnson

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Here are the results of using 17g or 18g sodium metaborate per 100 ml ,all developed 1+50 for 7.5 min 20C to compare with HC-110 1+47 for the specified time 7.5 min in the massive development chart.
The film leader with 17g metaborate is somewhat lacking in density and 18 g metaborate per 100 ml more closely matches HC-110, although it is rather hard to see from the attachment.
All get about EI=100 for this film, Delta 100, with evaluative metering [matrix metering Nikon].

I will make a field test using 18g metaborate to check before posting a formula.
 

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