Chemical storage - part 2

[Jorge Oliveira]

There was a thread sometime ago re Protectan - and propane/butane.

My fist findings using butane (gas lighter refuel bottle):

The paper developer bottle half full would bend towards the inner side without it, due to oxygen absortion by the developper. Now no more (and sometimes even to the ouside, like a barrel, due to excess butane).
The devloper (I use homemade ID-62) looks like new even with just one quarter bottle full after about a week (and before that 3/4, 1/2, etc). It was darker without butane.

I turn the butane bottle upside down and squeese the valve for 1~2 seconds inside the dev bottle and close the dev tight.

All the usual safety precaution apply.

Jorge O

 

[BobF]

Bravo Jorge, glad to see someone else has a test running. I am getting about the same results so far with a few differences.

I have mixed D-76 and 1/4 filled some small plastic Pepsi bottles and some small glass drink bottles for a control sample. My butane is reacting the same as yours but my air/dev combo has not sucked the bottle sides in. Because of the concern about explosiveness of Butane I also have used a Dust off like product and it seems to be absorbing into the developer as the bottles look like they have been in a crusher. All samples still look clear but I am not going to open most of them till six months has passed. I am opening and re-butaneing (is that a word?) one of the bottles monthly.

I also have a plastic bottle of d76 1:1 in the fridge to see how long I can keep working strength solution.

This is so much fun I just sit around and look at the bottles for hours :twisted:

 

[Jorge Oliveira]

Bob

I've used paper dev since it has less sulphite and more alkali, so I thought it would show the results more clearly.
Your 6 months test will be very interesting.

Eagerly awaiting,

Jorge O

 

[BobF]

I think you're right about it responding more quickly. I thought about using paper dev also for testing as it is stronger but I don't often store it for long and want real world results for film. I often have left over film dev. that I don't want to toss but if you risk using it later on good shots it's not so easy to just re-expose and develop again like with prints.

 

[Robert]

What are you using for bottles? I'm not sure I get the bit about the developer absorbing O2. If the developer absorbs oxygen shouldn't the developer then grow by a similar amount? It's not like the Oxygen disappeared.

Those plastic pop bottles will leak air over time. Not enough to be noticable with pop but it's happening.

 

[BobF]

Robert, I don't know either but I can tell you that simple observation of the container shows that whatever gas was filling the container has gone somewhere and I have to assume it has dissolved into the liquid thereby decreasing the gas pressure and causing the atmosphere to crush the container.??????

Part of the testing is to see if Pepsi type bottles are suitable as many have said. I don't know but will find out if soda bottles work as well as glass. I am not testing those brown photo bottles as I know they don't work as well as glass.

 

[Jorge Oliveira]

Robert
Oxygen reacts with the developer's salts (metol, sulphite, etc) and they become other salts.
Sulpite, if I'm not wrong, becomes sulphate - and useless as an anti oxydizer (but then it's there, among lots of other reasons, to protect the real developer agent's by absorbing oxygen).
This way, it occupies very much less volume.
It's quite well known the fact that a developer's bottle (tight closed) may look 'crushed' when partially filled if it's not strong enough. Try it!

Re brown bottles - they may not be good for long term storage, but I've never had problems with say one month.

Now, Bob's point re film developer in glass bottles makes a lot of sense.

Jorge O

 

[Ole]

One explanation for the "sucked-in" airfilled and "bulging" butaned bottles could be temperature changes. I do have a very old unopened bottle of Ilfosol-S whith sucked-in sides, so oxygen absorption is definitely taking place...

When you fill up a bottle wit hbutane, the gass expands. That cools it down. When you close the bottle, the butane is still below ambient temperature. As the gas warms up, it expands - bulging bottles!

 

[avandesande]

Butane will also pass through the walls of certain types of plastic bottles. Not a good choice of inert gas. It's probably worth it to spend a few dollars and get a nitrogen tank and regulator if this is what you want to do.

 

[BobF]

Butane will also pass through the walls of certain types of plastic bottles. Not a good choice of inert gas. It's probably worth it to spend a few dollars and get a nitrogen tank and regulator if this is what you want to do.

If it was only a few dollars you're right but I could thow away a lot of chemistry for the price of tankand regulator set up.

 

[glbeas]

I got a nitrogen tank for $60, a regulator for $40 and a refill for $14. The setup will last near forever andin nonexplosive.

 

[dr bob]

I got a nitrogen tank for $60, a regulator for $40 and a refill for $14. The setup will last near forever andin nonexplosive.

Bravo!

I'm glad to see I'm not the only "crazy person" doing this. I invested about the same amount way back in 1975 for air brush purposes. When I suggested using this setup for topping off developer on rec.photo.darkroom, I recieved a lot of criticism for having "dangerous" materials around. Of course any material under high pressure deserves careful handling but I know a lot of artists who use bottled gas. I use Argon. It is as cheap as nitrogen and more available around here, with all the welding and boats et c.

I use two regulators: one for gross bottle pressure and a second in series for more exact work. The second regulates from 2 to 50 psi and yields repeatable results with the air brush. Two-stage regulators are available at a higher cost. I have not done air brush for a decade now. Anyone interested in the equipment?

 

[Robert]

One explanation for the "sucked-in" airfilled and "bulging" butaned bottles could be temperature changes. I do have a very old unopened bottle of Ilfosol-S whith sucked-in sides, so oxygen absorption is definitely taking place...

When you fill up a bottle wit hbutane, the gass expands. That cools it down. When you close the bottle, the butane is still below ambient temperature. As the gas warms up, it expands - bulging bottles!

Ya but the whole should equalize in pressure over time. Pulling the gas into solution. So then it should end up someplace in between.

 

[Robert]

Well nitrogen shouldn't be anymore dangerous then C02 used by many people at home for everything from soda to beer. When you consider the average fast food place hires teenagers and they manage to keep from blowing themselves up it's not that hard. OTOH I'm sure every year some frat kid gets hurt but then I'd never suggest handling anything under pressure when drunk.

 

[avandesande]

The only practical danger of handling inert gasses like argon or nitrogen is the possiblity of the cylindar falling over and the head getting knocked off. The resulting projectile could result in death or injury. Chaining the cylindar properly to the wall will eliminate this possibility.

 

[Ole]

Ya but the whole should equalize in pressure over time. Pulling the gas into solution. So then it should end up someplace in between.

Butane doesn't dissolve very well in water - or in water-based solutions. The only way it could equalise is through leaking caps or diffusion through the bottle. Even water diffuses through plastic faster than butane does.
Butane is also surprisingly little explosive, and should be quite safe in the amounts used to top up a bottle. A single-use lighter contains enough butane to last several years if only used for filling bottles...

Another benefit of butane is that it liquefies easily, so relatively low pressure is needed to store it as a liquid. If your darkroom ever gets REALLY cold, you may see your butane condense to a fluid. I've only seen it outdoors...
Nitrogen needs a lot more pressure for compact storage - that's why nitrogen bottles are so much heavier. IMO the wight and pressure of nitrogen bottles make these far less safe than a bottle of butane!

 

[Jorge Oliveira]

I've only seen it outdoors...

Ole

I think you mean it in Norway, right?



Jorge O

 

[Silverpixels5]

Does anyone use tetraflouroethane to top off their chemicals? I've been using it, only because I don't have another source of relatively non-reactive gas. The only thing I dont' know is if it has any effect on what I'm storing since nearly half of it always goes into solution. I imagine the only thing that could oxidize the developer is the flourine, but I seriously doubt thats happening. So does it just dissolve into solution and live happily ever after, or is it having some effect that I'm not aware of? I havn't noticed any loss of effectiveness in my solutions, but until recently I also havn't been very meticulous in the darkroom either.

 

[BobF]

Does anyone use tetraflouroethane ............I havn't noticed any loss of effectiveness in my solutions, but until recently I also havn't been very meticulous in the darkroom either.

Hey, join my TOT club (Top Off Testing) and age your own pepsi bottle test containers with tetraflouroethane. Glass beer bottles would be even better.

 

[glbeas]

The only practical danger of handling inert gasses like argon or nitrogen is the possiblity of the cylindar falling over and the head getting knocked off. The resulting projectile could result in death or injury. Chaining the cylindar properly to the wall will eliminate this possibility.

Quite, thats why it lives behind the film dryer accessible from the edge of the sink. You can see it in my darkroom pictures if you look for it.

 

[dr bob]

"The only practical danger of handling inert gasses like argon or nitrogen is the possiblity of the cylindar falling over and the head getting knocked off. The resulting projectile could result in death or injury. Chaining the cylindar properly to the wall will eliminate this possibility."

Yes! That should have been mentioned. I have a little stand to hold the cylinder. Otherwise I lay it down on the floor.

 

[Aggie]

..

 

[Ole]

I've only seen it outdoors...

Ole

I think you mean it in Norway, right?



Jorge O

Ehm - yes. But much of the midwest can be really cold in the winter - unlike Brazil

I've even seen liquid propane when I was in the army in North Norway... Temperature went down to below -47°C: I don't know how cold, because the thermometer was frozen solid.

 

[dr bob]

another risk, albeit small, is if any form or a oil or grease should hit the top of the cylinder at the connectrion. It can cause it to start a fire and explode. Helps to have had a brother in law who was a fireman.

No! Neither Argon not Nitrogen are flamable in that respect. In fact, sudden release of pressure of these systems will cause a cooling effect - sometimes so great that the temperature can approach the temperature of liquid gases. The main problems stem from flying objects.

On the other hand high pressure air can certainly cause a fire if mishandled. That is one of the most underestimated hazards in my old engineering business. And forget hp Oxygen! Oxygen has to be one of the most hazardous materials in daily use. No smileys here. I worked with these compressed gasses at pressures exceeding 18,000 psi without incident, but I have been witness to oxygen fires (read:explosions). I was commissioned by the U.S. Navy to solve a problem on their electrolytic oxygen generators used aboard submarines. I now hold the patent on a new design still in use as far as I know. Because the generators also make Hydrogen at high pressures, no one else wanted to take on the project I found that the problem was _not_ the Hydrogen but the Oxygen. Actually, Hydrogen is a pussy-cat compared to hp Oxygen, which is unpredictable. Hp air has similar properties.

Whew! Got that off my chest.

 

[Silverpixels5]

Yea hp nigtrogen is pretty harmless. I used to fill liquid nitrogen tanks for the grad students back in college, and the room would fill with nitrogen...needless to say it got pretty cold in there. Actually the worse thing that ever happened was when one of the valve knobs was loose and actually came off when i was opening it. Liquid nitrogen sprayed all over the palm of my hand (with rawhide gloves on). I had a pretty good burn on my hand from that....