Using a syringe to keep liquid developers longer?

ChristopherCoy · Apr 16, 2021

I just had a thought. It's a scary thought, but none-the-less a thought.

I can only get to my dark room, which is 2.5 hours away, about twice a month. I've been thinking about how to keep my chemicals oxidation free for as long as I can. I researched mixing small batches of powdered developer just a few grams at a time, but the problem is that the particles are different sizes so settling in the bag will create consistency issues.

And then I thought about liquid developers in plastic containers, i.e. Multigrade or PQ Universal. The plastic containers they are in are relatively soft, and with a larger gauge syringe, you could technically pierce the plastic, draw out the amount you need for dilution, and then put a piece of tape over the hole to keep air out, all without breaking the factory seal. You'd just have to go down the side of the bottle as you withdraw chemical in order to reach it with the syringe.

Is this a ludicrous thought, or do you think it could possibly work?

grain elevator · Apr 16, 2021

What would be the advantage over screwing the lid back on? I'd say better go with the usually recommended means such as protective gas, squeezable or small bottles etc. Twice a month isn't that rare at all I think, I don't set up the darkroom in my bathroom more frequently than that, not having problems with chemical life.

runswithsizzers · Apr 16, 2021

As you withdraw the liquid from the container, one of two things is going to happen: either air will replace the volume of liquid that was removed, or the container will start to collapse.

You may have heard the expression that "nature abhors a vacuum" and that applies here. Removing liquid from a "sealed" container creates a partial vacuum inside, and when you withdraw the needle, outside air is going to be sucked in through the hole left by the needle. I doubt if covering the needle hole with tape will be 100% effective in preventing air pressure from eventually equalizing inside and out.

So, I think your plan would reduce exposure to air compared to opening the top and pouring liquid from the container, but I would expect there to be some infiltration of room air into the container. You will know you are successful if the bottle starts to collapse, and if it does not, you will know you are not maintaining a vacuum inside the bottle.

Consider as an alternative possibly replacing the volume of liquid you remove with some inert gas.

ChristopherCoy · Apr 16, 2021

grain elevator said:
What would be the advantage over screwing the lid back on? I'd say better go with the usually recommended means such as protective gas, squeezable or small bottles etc. Twice a month isn't that rare at all I think, I don't set up the darkroom in my bathroom more frequently than that, not having problems with chemical life.

The advantage would be that you don't have to break the factory foil seal under the cap, and by only removing liquid from the bottle with the syringe, you aren't introducing more air for oxidation.

Donald Qualls · Apr 16, 2021

Use Rodinal. And opened and reclosed, partially full bottle will last years.

Or mix your own from raw chemicals at time of use (there are formulae that work well without heating the water and waiting for it to cool as you'd have to do with D-76 or D-72).

Or mix stock solution to double strength (I've got Dektol I mixed that way, in distilled water, in 2005 -- still works).

ChristopherCoy · Apr 16, 2021

Rodinal? For paper developing?

So you just mix dektol with half the recommended water?

ChristopherCoy · Apr 16, 2021

runswithsizzers said:
As you withdraw the liquid from the container, one of two things is going to happen: either air will replace the volume of liquid that was removed, or the container will start to collapse.

.

I figured the bottle would collapse as you remove liquid. But if it stays that way then at least I would know that air isn't getting sucked in, which would mean that my developer is staying good for longer.

Andrew O'Neill · Apr 16, 2021

Just get some PET bottles, and squeeze the air out. I do this at school where I teach photography. Works great.

Donald Qualls · Apr 16, 2021

ChristopherCoy said:
So you just mix dektol with half the recommended water?

Yep. The batch I had was five gallons, and I didn't have five gallons of storage. Water has to be hot to do it, but everything stayed dissolved when it cooled down to room temp. As a bonus, it apparently never froze (some was in glass, would have broken the jar) sitting in my shed through four winters after my move. Don't worry about color (it'll be darker than you're used to), and be sure to mark the containers to remind you to use 1+3 instead of 1+1 or 1+5 instead of 1+2.

Andrew O'Neill said:
Just get some PET bottles, and squeeze the air out. I do this at school where I teach photography. Works great.

PET is a bad choice for squeezing, I've found. I used PET bottles sold with club soda inside, squeezed them, and the active one developed a hole where the plastic creased when it was about half full -- lost 200+ ml of Flexicolor color dev replenisher before I caught it. My current preference is to store in glass or PET (without squeezing) and blanket the liquid with butane lighter fuel. It's enough heavier than air to form a blanket inside the bottle (demonstrated by the fact that PET bottles handled this way don't shrink from the developer sucking the oxygen out of the trapped air).

ChristopherCoy · Apr 16, 2021

Donald Qualls said:
and blanket the liquid with butane lighter fuel. It's enough heavier than air to form a blanket inside the bottle (demonstrated by the fact that PET bottles handled this way don't shrink from the developer sucking the oxygen out of the trapped air).

How do you know when there is enough butane in the bottle? I'm assuming you just turn a cigarette lighter upside down and hold the button down a few minutes?

runswithsizzers · Apr 16, 2021

Donald Qualls said:
[...] My current preference is to store in glass or PET (without squeezing) and blanket the liquid with butane lighter fuel. It's enough heavier than air to form a blanket inside the bottle (demonstrated by the fact that PET bottles handled this way don't shrink from the developer sucking the oxygen out of the trapped air).

I use a similar technique in my woodworking shop to keep partially full cans of varnishes and enamels from hardening. I stick the nozzle of a butane torch in the paint can and open the valve for a few seconds before sealing the lid. Obviously, one must keep in mind that these are flammable gasses.

Rick A · Apr 16, 2021

Christopher, when I used D-76 I mixed the full gallon, then decanted it to smaller plastic bottles. I used 8 ounce water bottles and squeezed the excess air out and capped tightly. I've had this developer last over three years this way. I also switched from Dektol to LPD paper developer, it lasts forever(or so it seems), and is replenishable. Stop and fixer solutions can be mixed from concentrate at time of use. If you want to use butane for replacing the air in your bottles, get a canister of Ronson butane lighter refill and squirt a two or three second burst into the bottle, just be careful not to shake the contents of the bottle afterward.

Donald Qualls · Apr 16, 2021

ChristopherCoy said:
How do you know when there is enough butane in the bottle? I'm assuming you just turn a cigarette lighter upside down and hold the button down a few minutes?

A few seconds is all it takes. You don't need to displace all the air; the butane will settle to and form a blanket (it's enough heavier than air to stratify when the bottle is still).

Rick A said:
get a canister of Ronson butane lighter refill and squirt a two or three second burst into the bottle, just be careful not to shake the contents of the bottle afterward.

Why not shake? Yes, that will mix the butane and air, but butane is enough denser (molecular weight 58, twice that of air, hence twice the density) that it will settle into a layer again once it's left to stand for a while.

gone · Apr 16, 2021

Physics says that 2 objects cannot occupy the same space at the same time. Your plastic bottle came to you w/o air (maybe a little at the top). Taking a syringe to it and withdrawing the fluid won't introduce any more air into the bottle, except when you pull the needle out, and at that point I would imagine that there would be some small fluid initially lost. Might work. Easy enough to try it w/ a plastic bottle filled w/ water and see what happens.

mshchem · Apr 16, 2021

Use Adox Rodinol, the bottle has a restriction that allows for a blunt tip needle. It's really genius. I normally pour into a Nalgene 10 ml graduated cylinder . For XTOL I package into 125 and 250 mL singles, that are ready to go. I buy bottles.

Rick A · Apr 16, 2021

Donald Qualls said:
A few seconds is all it takes. You don't need to displace all the air; the butane will settle to and form a blanket (it's enough heavier than air to stratify when the bottle is still).

Why not shake? Yes, that will mix the butane and air, but butane is enough denser (molecular weight 58, twice that of air, hence twice the density) that it will settle into a layer again once it's left to stand for a while.

Because what O2 is in the bottle will mix into the developer regardless of the butane.

wiltw · Apr 16, 2021

There are bottles of nitrogen which are used to keep open bottles of wine longer, too. Not flammable like butane!

pentaxuser · Apr 16, 2021

Rick A said:
Because what O2 is in the bottle will mix into the developer regardless of the butane.

Shouldn't that be " what O2 is already in the bottle before it was sealed has already mixed into the developer" That sounds correct but as Donald says a heavier inert gas displaces any additional air that is sucked in as the developer is dispensed so oxidation does not get worse?

pentaxuser

Donald Qualls · Apr 16, 2021

Reaction of oxygen in the bottle with sulfite in the developer takes time -- shake the bottle, and the air that gets dispersed into the developer will have a chance to dissolve, and you'll momentarily increase the area of the liquid-gas interface by a large factor, so you'll get some additional reaction -- but in a few minutes, the stratification will be reestablished, bubbles in the developer will have come to the surface and burst, and things will be as they were before the shaking.

You can't dispense the liquid without losing the butane blanket (unless you use a tube to suck up the liquid without disturbing the bottle), so you'd have some exposure at each use anyway -- but if that's all the exposure you have, the developer will still last much longer than its usual "official" shelf life. The same is probably true by simply closing the bottles (they won't get disturbed sitting in a darkroom for several months at a time), but the butane blanketing will prevent the developer reacting with the oxygen trapped in the bottle as it otherwise would.

Nitrogen doesn't work as well -- it's actually slightly lighter than air, so you have to fully displace the air in the bottle to gain by it. Argon does work (similar density to butane and inert), but it costs more than butane.

mshchem · Apr 16, 2021

wiltw said:
There are bottles of nitrogen which are used to keep open bottles of wine longer, too. Not flammable like butane!

Argon.

mshchem · Apr 16, 2021

I remember syringe pumps from early liquid chromatography . We would sparge all the solvents with Helium, this would remove the dissolved gases from the solvents. Otherwise like "the bends" when the liquid entered the lower pressure detector cell it would suffer from bubbles of air.

ChristopherCoy · Apr 16, 2021

@jay moussy solved my problem. Wine pouches! Who wouldda thunk?

mshchem · Apr 16, 2021

ChristopherCoy said:
@jay moussy solved my problem. Wine pouches! Who wouldda thunk?

These are genius. I don't drink, there's a make your own shop nearby. I need to see if they have.

Donald Qualls · Apr 16, 2021

I bought a package of five 5L wine pouches, with a box, from an Amazon seller. Free 2-day shipping with Prime, and that's enough for two or three years of my usage of Xtol. And unless the pouches have a one-time closure (haven't opened the package yet), they ought to be reusable.

Andrew O'Neill · Apr 16, 2021

Donald Qualls said:
Yep. The batch I had was five gallons, and I didn't have five gallons of storage. Water has to be hot to do it, but everything stayed dissolved when it cooled down to room temp. As a bonus, it apparently never froze (some was in glass, would have broken the jar) sitting in my shed through four winters after my move. Don't worry about color (it'll be darker than you're used to), and be sure to mark the containers to remind you to use 1+3 instead of 1+1 or 1+5 instead of 1+2.

PET is a bad choice for squeezing, I've found. I used PET bottles sold with club soda inside, squeezed them, and the active one developed a hole where the plastic creased when it was about half full -- lost 200+ ml of Flexicolor color dev replenisher before I caught it. My current preference is to store in glass or PET (without squeezing) and blanket the liquid with butane lighter fuel. It's enough heavier than air to form a blanket inside the bottle (demonstrated by the fact that PET bottles handled this way don't shrink from the developer sucking the oxygen out of the trapped air).

I've never had an issue.

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