Chemical oxidation and vacuum wine stoppers!

[rwhb12]

Darkroom liquid chemicals, we are told, have shelf lives because they deteriorate with air in the bottle.

Having seen and purchased vacuum wine stoppers (put vacuum wine stopper in Amazon search bar) and used them on glass bottles filled with Perceptol etc., they appear to work well. But the question is is a partial vacuum enough to prevent or reduce deterioration for part time darkroom workers like me? The other question is they say not to be used for non domestic use. I guess this is only because of marketing?

i have to say it is great to be part of this forum - I am not alone!

russell

 

[Steve Smith]

they appear to work well

Then that's all you have to worry about.

The other question is they say not to be used for non domestic use. I guess this is only because of marketing?

Once you have bought it, you can use it for whatever purpose you like.

Sometimes there are suggestions to replace the air with CO2 but that will cause the developer to become more acidic as CO2 absorbed by water becomes carbonic acid.

p.s. It's oxidisation, not oxidation - and don't let any Americans convince you otherwise!


Steve.

 

[markbarendt]

Darkroom liquid chemicals, we are told, have shelf lives because they deteriorate with air in the bottle.

Having seen and purchased vacuum wine stoppers (put vacuum wine stopper in Amazon search bar) and used them on glass bottles filled with Perceptol etc., they appear to work well. But the question is is a partial vacuum enough to prevent or reduce deterioration for part time darkroom workers like me? The other question is they say not to be used for non domestic use. I guess this is only because of marketing?

i have to say it is great to be part of this forum - I am not alone!

russell

Hi Russel,

The wine stoppers are a fine idea, especially if you are recycling a bottle that can use it.

Some people add marbles to their bottles to "top up" the fluid in bottle and eliminate any air space before capping, that works with any cap. Others use accordion style collapsable bottles.

For bottles holding small amounts of chemical I just displace the air with a shot propane/butane.

My favorite method of storage of prepared chemicals is a "wine box"; once it's empty it gets a good bath, then I make up the chemical and pour it in the bladder, reinsert the valve, expel all the air, then put it back in the box. This allows dispensing without introducing any air into the storage container.

All of these methods help and are worth doing, but none give me the confidence to go much past the manufacturers recommended storage times.

Simply put, the cost of the chemicals is so small compared to the rest the costs of getting a shot that it simply isn't worth messing with.

 

[gleaf]

Slight pair of sideways. How we preserve precision electronic parts for decades is under a dry nitrogen blanket. Slight low pressure bleed into a closed small storage shelf space. Inert gas is interactive. So only the contaminates will continue to react.

Wine box bladders.. is there enough flow for direct to Nikor type tanks or is bladder storage only?

Have been considering using cubitainer type storage. The wine bladder should be less porous.

For now it's half gallon rectangular jugs, not elegant but pours fast.

 

[sepiareverb]

Bloxygen is my method. Has worked beautifully for me with all kinds of developers including the finicky Studionol.

 

[markbarendt]

For me the wine boxes are typically for storage of "stock" mixes that need to be; measured for dilution, measured for replenishing, or are measured directly into JOBO beakers for printing.

The bladders flow real quick when full, when getting the last bit though, its slow.

 

[pentaxuser]

The bladders flow real quick when full, when getting the last bit though, its slow.

True and some bladders seem better than others but all will get nearly all the liquid out and the last remaining drops can be squeezed out by taking the bladder out of the box and squeezing by hand. By that stage the bladder anyway needs a clean out or if it is the same liquid to go back in, then a simple re-fill. Each bladder will do several re-fills before you have to buy a new wine box and drink the filthy stuff again to get a fresh bladder.

It's a dirty part of the whole process but someone's got to do it. Lots of sacrifices have to be made in photography

pentaxuser

 

[fotch]

Replacing air with nitrogen I think is the preferred method although it may not be practical/affordable for everyone. Its not just the cost savings of chemicals, rather, the convenience of having chemicals ready to use that you can trust, without always mixing fresh. JMHO

 

[markbarendt]

True and some bladders seem better than others but all will get nearly all the liquid out and the last remaining drops can be squeezed out by taking the bladder out of the box and squeezing by hand. By that stage the bladder anyway needs a clean out or if it is the same liquid to go back in, then a simple re-fill. Each bladder will do several re-fills before you have to buy a new wine box and drink the filthy stuff again to get a fresh bladder.

It's a dirty part of the whole process but someone's got to do it. Lots of sacrifices have to be made in photography

pentaxuser

Speaking of that.

 

[mgb74]

I've used those wine stoppers for wine, but never did any tests to see just how long they keep their vacuum. I suspect the point about "not to be used for non domestic use" is not about marketing, but rather that the seal is not reliable enough for industrial use (or tested, certified, whatever).

I use brown beer bottles and a bottle capper (available at any homebrewing shop). I can fill very close to the top so only a bit of air. I can fill 12 or 22 oz bottles, so can tailor the size to what I need. A partial bottle gets a wine cork for a stopper. Obviously needs to be labeled (but I don't store beer in my darkroom).

 

[gone]

Oxidation is only part of the issue. Heat plays a large roll as well. I use D76 in those brown plastic bottles from Freestyle, as well as a couple of accordion plastic bottles. This works fine, but 4-5 weeks is all I'll go w/ this developer. I like the wine bottle idea (any excuse to buy more vino rosso is a good one). Don't have any caps for them though, and I had no success trying to just put a cork in a bottle full of developer, so for now the bottles are for a nice decorative display.

 

[GRHazelton]

Canned air??

Any thoughts on using canned air to exclude air from developer bottles? Since the canister warns against using near ignition sources I assume the stuff is flammable, perhaps propane, butane? Would be necessary to keep canister more or less upright and release the gas through the furnished wand gently, to avoid splashing, etc. Since I have this stuff around for dusting off negs prior to scanning or enlarging it would be really handy.

 

[GRHazelton]

Since chemical reactions roughly double/halve in speed with each 10 degree C change, storage in the fridge sounds good ... or is it? Any thoughts on using a fridge at perhaps 35 F? Would there be a problem with precipitations which wouldn't then redisolve?

 

[bsdunek]

Since chemical reactions roughly double/halve in speed with each 10 degree C change, storage in the fridge sounds good ... or is it? Any thoughts on using a fridge at perhaps 35 F? Would there be a problem with precipitations which wouldn't then redisolve?

Yes, there will problem with precipitation, and it will be difficult to redisolve. Most of the solutions are nearly saturated.

As far as vacuum corks holding their seal for a long time - I've left partial wine bottles with them for a week or more, and they still seem to be sealed. Not that its good for the wine, it's just that we were on vacation and a partial bottle got left at home.

 

[sewarion]

I am using a system of vacuum wine stoppers too and it has definitely improved the longevity of my darkroom chemicals. Using fix for papers over months (low frequency, though) can be done with no problems, whereas I had problems with fix going stinky (very sour) in non-vacuumized bottles, in particular if they only half full.

if the bottle is filled full or just to a quarter seemingly doesn't matter as long as the vacuum is kept. unfortunately, you can only really check the next time you open the bottle, as there is usually a 'pop' if the vacuum was kept and no such sound if it wasn't. i usually put a drop of water (or spit, for that matter) around the very area of the stopper that would contact the bottle before pumping the air out of it and it generally holds up very well. for me the method has solved about any oxidation problem i have come across in the past, so i can only advise you to stick with it, in particular if you already have the equipment.

 

[bvy]

Any thoughts on using canned air to exclude air from developer bottles? Since the canister warns against using near ignition sources I assume the stuff is flammable, perhaps propane, butane? Would be necessary to keep canister more or less upright and release the gas through the furnished wand gently, to avoid splashing, etc. Since I have this stuff around for dusting off negs prior to scanning or enlarging it would be really handy.

Do you mean canned air in general, or the "dust off" stuff? I would avoid the latter. Look into a product called Bloxygen. It's nonflammable and inert (argon). Displacement is still my number one method, however.

 

[Jim Noel]

Hi Russel,

The wine stoppers are a fine idea, especially if you are recycling a bottle that can use it.

Some people add marbles to their bottles to "top up" the fluid in bottle and eliminate any air space before capping, that works with any cap. Others use accordion style collapsable bottles.

For bottles holding small amounts of chemical I just displace the air with a shot propane/butane.

My favorite method of storage of prepared chemicals is a "wine box"; once it's empty it gets a good bath, then I make up the chemical and pour it in the bladder, reinsert the valve, expel all the air, then put it back in the box. This allows dispensing without introducing any air into the storage container.

All of these methods help and are worth doing, but none give me the confidence to go much past the manufacturers recommended storage times.

Simply put, the cost of the chemicals is so small compared to the rest the costs of getting a shot that it simply isn't worth messing with.

My experience with the wine boxes is that the bladders permit osmosis over fairly short periods of time, thus allowing oxygen to enter. THe "wine pumps" work pretty well.

 

[Nikola Dulgiarov]

Any thoughts on using canned air to exclude air from developer bottles? Since the canister warns against using near ignition sources I assume the stuff is flammable, perhaps propane, butane? Would be necessary to keep canister more or less upright and release the gas through the furnished wand gently, to avoid splashing, etc. Since I have this stuff around for dusting off negs prior to scanning or enlarging it would be really handy.

Canned air generally consists of polyfluorinated alkanes - di-,tri-, tetrafloroethane. They're heavier than air and reasonably inert. Burning does release fluorine compounds, so be careful.

 

[ozphoto]

I was very surprised by how well they work - raided some my folks had been given (they had plenty!!!) and stoppered a couple of bottles of dev. 6 months later it was still *very* useable. I couldn't detect any oxidisation and it worked perfectly.

Longer than 6 months? Not sure - it will certainly be there when I visit AU again, so I guess I'll find out sooner or later, just how good they do seal a bottle.

 

[MattKing]

I'm wondering if their greatest effect is improving the strength of the seal of the cork/stopper.

Because otherwise it just seems that the reduction in oxygen in the bottle would be minimal.

 

[David Allen]

If you mix developer, fixer, wash-aid, etc yourself then there is no storage problem because they are so cheap to make from raw chemicals that you do not need to store working strength over long periods - you simply throw away after use. In addition, most liquid chemicals at stock strength will last for ages (HC110 for example will last more than 3 years if stored at stock strength and used one-shot). With working strength chemicals (with the exception of two-bath developers, selenium toner, etc) it is best not to store them over long periods because this is a false economy resulting in unpredictable results.

The key question with storing working strength chemicals over long periods is whether you are actually being economical. For example, if you use Dokumol print developer, 1 litre at working strength (I use 1 + 6 strength) is enough to develop 10 final 16 x 12 prints including test strips and work prints - I always feel that I have 'had my monies worth' with 10 final prints and would not store for further use although Dokumol will deliver good results if you do store for a few weeks. Having achieved 10 good prints in a session why would you want to store the developer for further use?

Don't get me wrong, I am not loaded and can't afford to just throw away good chemicals but after all of the effort in finding images I do not want to take risks with developing the film. With printing, a good testing regime for the fixer (two-bath) is far more important than trying to save a few bob by storing the working strength fixer for months before a new printing session.

Perhaps if you could explain which chemicals you are trying to store over long periods, everyone here could provide better advice in terms of whether there is an appropriate storage method, whether it would be more economical to mix fresh chemicals (i.e. changing to HC110 one shot for film development) or whether you are trying to make a false economy (i.e Tetenal Lavaquick when mixed at 60ml + 1000ml water has an archival capacity of 30 prints at size 16 x 12 and should not be used beyond this).

Bests,

David
www.dsallen.de

 

[RalphLambrecht]

Then that's all you have to worry about.



Once you have bought it, you can use it for whatever purpose you like.

Sometimes there are suggestions to replace the air with CO2 but that will cause the developer to become more acidic as CO2 absorbed by water becomes carbonic acid.

p.s. It's oxidisation, not oxidation - and don't let any Americans convince you otherwise!


Steve.

steve, you lost that battle hundreds of years ago, give it up.

 

[Steve Smith]

steve, you lost that battle hundreds of years ago, give it up.

If you can show me something which has oxidated rather than oxidised, then I will agree that oxidation is a word!


Steve.

 

[RalphLambrecht]

If you can show me something which has oxidated rather than oxidised, then I will agree that oxidation is a word!


Steve.

a word is a word not because it's in the dictionary butwhen a group of people use it with the same understanding of its meaning;oxidation is a word, and you know that there is such a group; you possibly included.

 

[fotch]

I agree with Ralph.