Crystallizing Borax

[chris_raney1]

<p>Lately, I've decided to experiment with different formulas of divided D-76. So far I've used Vestal's version of the mix with very good results. Then I began thinking that perhaps Photographer's Formulary might have improved on the formula, so I happily whipped-up their version and poured it into my lovely, brown glass bottles. Solution B called for 60 grams of borax per litre, so I dissolved 240 grams in heated, distilled water to make a gallon.</p>

<p>The next day the bottom of the bottle looked like there had been an overnight frost; a substantial portion of the borax had precipitated out and had formed into large crystalline clumps. I shrugged my shoulders, poured the solution into my glass Griffin beakers, stirred it up, dissolving what I could (I was about to use it, so I didn't heat it up) then filtered the solution back into the bottle.</p>

<p>When I unstrung part of a roll of film during the wash cycle I kept unspooling, waiting for an image to appear...though there was none. Both rolls of film I had just developed were completely blank...as if they had been unexposed. In a moment much more painful than a rookie's mistake, my precious, irreplaceable images...were gone. </p>

<p>Vestal's solution B calls for a mere 2 grams of borax per litre, though it is mixed in solution with 50 grams of sodium sulfite. How in the world could a bit less than Formulary's 60 grams--given the crystals I had filtered out--not have been able to render an image for me? Would I be answering my own question by suggesting that the sodium sulfite is the savior, and perhaps is the true and necessary accelerant in Vestal's mild borax solution B? </p>

<p>The question I originally intended to pose was this: is there anything I can safely mix in with that heavy amount of borax that will keep it from crystallizing? Assemble, wisened alchemists, and give me your thoughts. </p>

[vince-p]

<p>The problem might be with your A solution, not your B. I get the chrystallized borax at the bottom of the bottle but since it's a plastic bottle I don't know about it til I clean it out. Everything develops ok. I use the Tom Abrahamsson formula which is out there in the Interzone.</p>

<p>Anyway just for kicks post your A solution formula for all to see.</p>

<p> </p>

[Alan Marcus]

<p>The developing agents in common usage are reducing agents with an affinity for oxygen, able to liberate metals from their salts. The ones used in photography must be able to differentiate between exposes vs. unexposed silver halogen crystals. It is the job of the developer is to reduce exposed crystals, splitting them into their two component parts. The silver to remain imbedded in the gelatin of the film, the halogen fraction (bromine or chlorine or iodine) is to dissolve into the waters of the developer. Most developing agents are derivates of benzene (originally derived from coal). When spent and oxidized they revert back to coal tar (black stuff).</p>

<p>Generally, these agents will not develop a silver image unless conditioned by an alkaline activator. Once the activator is added as one of the constituents of the developer, the agent can now reduce silver salts. A well know activator is sodium hydroxide. Other activators are sodium carbonate and borax. Borax is on the bottom of the list as to activity.</p>

<p>The activity is a function of the pH of the developer solution. While the pH is affected by several factors, it is the alkali employed that is the controlling factor. Developers using sodium hydroxide have a pH of about 12, sodium carbonate pH 10, borax finishes off with the least activity at pH 8.</p>

<p>As to solvents: Water is the chief solvent and because of this, developers are mainly water. Sometimes water is supplemented by a second or even third solvent. This is true if the solution will be highly concentrated. Diethyleneglycol (similar to anti-freeze) is commonly used as is some alcohols. Care is required if a second or third solvent is to be used because most will interfere with satisfactory development. </p>

[chris_raney1]

<p>Thanks for the lecture, Alan, but you missed the question: why does solution B, a solution of a gallon of distilled water and 240 grams of borax simply precipitate into crystals in the bottom my my glass jug? None of my other chemicals has ever done this: not pre-packaged Kodak F-5 hardening fixer; not my sodium sulfite concentrate (for hypo-clearing); nor any of my developers; nor my scratch-made, non-hardening F-24 fixer I use for paper prints to be toned. </p>

<p>Solution B is a use-and-discard chemical; the stuff in the bottle has never come in contact with a photographic emulsion. When I used the Vestal B formula of 2 grams of borax to 50 grams of sodium sulfite there was never this crystallization. Yes, I just spent my afternoon whipping up a new batch of Vestal formula, but I still want to solve this mystery so I can see if the Formulary recipe is a superior developer. </p>

<p>I don't know about the rest of you, but I just love to solve one of these old-school (as my students say) conundrums! So, what the hell turns the pure borax solution into gunk? Would adding sodium sulfite to the solution solve this chemical suspension problem?</p>

[Alan Marcus]

<p>As you know when you cause a chemical solution to be more highly concentrated then normal under conditions like higher temperature or pressure, the solution is said to be supersaturated.</p>

<p>Once a supersaturate lowers in temperature or pressure a precipitate forms. Crystals form around impurities. The crystals you dissolved were formed around impurities. Even though you mixed in distilled water, the impurities were induced forming around the constituent of the original crystals. </p>

[vince-p]

<p>Okay, so Alan, why did his negatives come out blank? That's the core mystery after all.</p>

[Alan Marcus]

<p>I do not know! However, I can tell you that the alkalis used are ones that exert a buffer action that resists pH changes. My guess it the pH of the final solution was closer to neutral and this interfered with the ability of the developing agent to differentiate between exposed and unexposed silver salts. </p>

[jay_de_fehr]

<p>Chris,<br>

If you're using the decahydrate form of borax, the solubility is 4.7% @ 68F. 60g/ liter is a 6% solution. That would explain the crystallization. The pH of a saturated solution of borax decahydrate is 9.32. If the temperature of your solution fell below 68F, more of the borax would crystallize, and would remain unavailable to the solution, decreasing the pH of the solution. If enough borax crystallized to reduce the pH beyond that required by your formula, it might result in blank film, but that seems unlikely. What seems more likely is that sodium sulfite is needed to catalyze the superadditivity between the metol and hydroquinone. If I was formulating a developer of this kind, I think I'd put sulfite in both baths, but surely this formula has been tested and found to work, as given. A real mystery. I can see no reason why your B solution shouldn't do its job. <br>

As for dissolving your borax, I'd say add another liter of water to make something closer to a 4.7% solution, and see if that does the trick. </p>

<p> </p>

[Alan Marcus]

<p>Superadditivity:<br>

I know nothing about this !<br>

I do know that developing solutions must be preserved because once the developing agents are dissolved in water, dissolved oxygen reacts. The reaction reverts the developing agents back to coal tar forming highly colored and staining compounds. The preservative used is sodium sulfite. It does double duty. It retards aerial oxidation. It reacts with the colored oxidized products rendering them colorless thus harmless. Eventually a used developer turns dark and should be discarded. </p>

[jay_de_fehr]

<p>Alan,</p>

<p>Sodium sulfite plays other roles as well as preservative; it also acts as a catalyst in MQ/PQ developers, as a mild alkali (the sole alkali in D23 and other developers), and a mild silver solvent in sufficient concentrations. There are very few sulfite-free developers.</p>

[chris_raney1]

<p>Wow, now we have a discussion going on! And yes, I live a bohemian existence in an old garage apt with neither central air nor heat, so the chemicals <em>did</em> get chilly that night. But they perhaps dipped no lower than 60 degree F, and the other chemicals weren't affected. I whipped-up the standard Vestal formula that does take 50 grams per litre of sulfite in the B mixture, and the next day everything was clear and lovely in the glass bottle.</p>

<p>Obviously, 60 grams per litre is a heavy saturation of Twenty Mule Team Borax. Yeah, that's right, I've been using the stuff out of the grocery store for years now and it's never acted up on me before. Though in truth the Vestal B solution only calls for 2 grams of borax per litre--I bump that to 16 grams, and this plus the 400 grams of sulfite in that gallon--which is then cut in half for a working solution of B--has always mixed up clean and clear for me.</p>

<p>Sodium sulfite in the solution B, is the answer? Should I simply default as Vestal did and mix the sulfite 50/50 between solutions A and B? </p>

[jay_de_fehr]

<p>Chris,</p>

<p>Are you saying the same A solution worked as expected with the sulfite/borax B solution? If so, it seems the sulfite must be the missing ingredient. Or, did you make a new A solution, too? In that case, do you still have the PF A solution? Have you tried it with the Vestal B solution? </p>

<p>If it were me, I would definitely put some sulfite in the B solution, if I was using an MQ 2-bath developer. </p>

[chris_raney1]

<p>Actually, I tossed all of it and went back to the Vestal formula. But if I try the PF formula, I'll be forced to experiment with the solution B, not knowing how much sulfite I should include in that formula. I suppose I could split the sulfite equally between A & B (as anecdote has it Vestal did, after forgetting to which bottle it should be added). </p>

<p>The beauty of the original, and perhaps even the original split formula was that bromide needn't be added to the mix. The sulfite was the secret, obviously.</p>

<p>But I'm here to learn, so I just might try it. </p>

[steve_faber]

My old 2 bath formula uses a saturated solution of borax for B.

It also had a warning that the temperature must not go below 60

degree F. Now I think we know why. I'm not sure why the borax

would not re-disolve though.