Carbon Dioxide compressed air - good at stopping oxidation?

Gerald C Koch · May 24, 2011

I haven't seen any definitive study as to whether these systems to replace air in bottles with inert gas actually works. Some systems use a high pressure gas canister which probably creates a vortex and sucks in as much air as replacement gas.

Photo Engineer · May 24, 2011

In NYS, Butane or Propane tanks are not permitted in stores attached to malls due to the danger associated with these.

The other threads, I repeat, contain a wealth of information on this.

PE

Gerald C Koch · May 24, 2011

The best ways to insure that your solutions remain fresh is to

o buy a size appropriate for your immediate need.
o store the solution in a suitable container. Use glass, PETA or PVC bottles for developers.
o use the solutions in a timely fashion. This may require planning ahead so that you have enough exposed film to develop or for prints that you have selected the negatives you wish to print.

Newt_on_Swings · May 24, 2011

In NYC you cant even transport or have in possession propane tanks at all in Manhattan, they are illegal.

Bob-D659 · May 25, 2011

Really, http://www.manhattanpropane.com/

Besides, were really discussing Ronsonol 4.5 or 6 oz cans of butane for refilling lighters, probably available in almost every grocery store, etc.

Steve Smith · May 25, 2011

Newt_on_Swings said:
In NYC you cant even transport or have in possession propane tanks at all in Manhattan, they are illegal.

What about propane accessories?!

Steve.

jm94 · May 25, 2011

As i bought the kodak developer, (4 lots of 5L), the problem of using it all is reduced somewhat... i thought about even cutting up some plexi in a circle and leave that floating on the liquid once ive mixed the right quantity with my working solutions and then remove the plexi when i need to access the A and B concerntrates again..RA4 is very hard to buy in small quantities, the rollei monoconcerntrate isnt enough, and ive read not-so-good reviews concerning monos. and the next step up is the kodak 4 lots of 5L. Would be a "once in 6 months" purchase given the volume of printing i like to do! Have loads of fix, am just wondering where i can get bleach on its own to save a few at the moment, especially as I am just starting out and money is tight at the moment.. for working solutions... zoom bottles will do the trick nicely cost an arm and leg near enough for a bottle but its a one time purchase unlike any spray

michaelbsc · May 25, 2011

Bob-D659 said:
Really, http://www.manhattanpropane.com/

Besides, were really discussing Ronsonol 4.5 or 6 oz cans of butane for refilling lighters, probably available in almost every grocery store, etc.

Correct. Or at least that's what I thought we were talking about. That's what *I'm* talking about. For that matter you can just use a lighter. Just don't strike the flint.

Somewhere along the lines you have to let people use some common sense. And if they don't maybe the Darwin principles apply.

EDIT: Or you can tear the pizeio crystal out of a barbeque grill lighter. Then you have point to stick down inside the bottle.

hrst · May 25, 2011

hoffy said:
You also don't need to displace ALL the air out of your containers with the butane. Since butane is heavier then ambient air, all is required is enough to form a barrier to cover the top of the solution. This is probably no more then a short puff.

This is the common Internet theory and it indeed makes sense....

But have you really tried it and compared results side to side, in a controlled test?

I have, and I found out that a short puff was of little protection. You really needed a long puff to have good protection and even that did not provide the same level of protection as squeezing the bottle.

I use the combination of butane AND refrigerator as a last resort if I just cannot squeeze the bottle for some reason.

For a REAL gas protection, the only way to go is a nitrogen or argon cabinet filled with complete inert gas atmosphere. "Puffing" from the bottleneck in normal room atmosphere leaves air in the bottle, and the barrier theory for heavier gasses doesn't seem to work in reality.

postalman · May 25, 2011

Just to answer the original question 4 pages ago, those dust removal sprays are neither CO2 or air, they're a refrigerant. Usually R134a or sometimes R152a. They should be fairly inert (although R152a is flammable), but it's been too long since I studied chemistry to guarantee that.

Gerald C Koch · May 25, 2011

jm94 said:
zoom bottles will do the trick nicely cost an arm and leg near enough for a bottle but its a one time purchase unlike any spray

By "zoom bottles" do you mean those accordian pleated bottles? If so they should not be used for developers as the plastic they are made from is permeable to oxygen which really defeats their intended purpose. They're OK for other soltions but are impossible to clean thoroughly.

PETE (polyethylene terphthalate) plastic bottles are a good choice and can be free as they are used for many beverages.. To find them check the recycle number on the bottle it should have a 1 inside the triangle. I use empty Powerade bottles for developers.

Bob-D659 · May 25, 2011

Every package of "canned air" I've seen always has the CAS number on it. Pretty easy to google it and find out exactly what the contents are.

For others, CAS 75-37-6 = R152a, 811-97-2 = R134a. Usually there is no bitterant in R134a canned air, there is in the R152a, as it is abused by "sniffers".

jm94 · May 25, 2011

http://www.firstcall-photographic.co.uk/products/850/ap-chemical-storage-bottle-3395z-1-litre is the bottle i am talking about, and as for the refregerant post, i found R134a on one of the bottles in one of the computer shops... but didnt buy it as i didnt know what it was.... cheaper, too actually!
if the zoom bottles are impermable to oxygen, if it takes a long time, i would use the working solutions reasonably quickly (within a month for b/w not sure about RA-4), i found 100ml to 900mlwater of firstcall print NE yields about 80 - 100 decent prints!

michaelbsc · May 25, 2011

Refrigeration increases the amount of dissolved O2 in water. Unless other more damaging reactions are retarded by temperature then storage at ambient is probably better.

hrst · May 26, 2011

michaelbsc said:
Refrigeration increases the amount of dissolved O2 in water. Unless other more damaging reactions are retarded by temperature then storage at ambient is probably better.

Again more Internet theories --- have you studied this in a controlled test?

I have and I can tell you that you are "probably" wrong.

Refrigerated sample -- a little bit of XTOL in the bottom of a bottle full of air -- was the best sample, producing around the same density (or a little better) than the second best sample -- a completely squeezed bottle with practically no air, stored at room temp.

I think this is because there is a certain amount of dissolved O2 in the solution and it keeps constant after the bottle is closed. This is especially true when the air is squeezed out, but even with a half-full bottle your theory didn't seem to have a visible effect.

Then, reducing the temperature simply slows down the oxidation reaction as well as other reactions.

As stated before, the samples stored with butane were inferior; especially the one that had only short "puff" of the gas that was quite close to the one with no protective gas stored similarly at room temperature.

Of course, I won't suggest refrigerating everything blindly. I'm just telling the results of my test. If you go too low in temperature, there may be precipitation problems. The best bet would probably be to store in a "cool" place, near the minimum temperature limit by the manufacturer -- usually 10 deg. C.

However, as said before, RA-4 developer is VERY robust and you don't need any special protection for short term storage like a few months. If you are going to keep it for more, then just use squeezable PET soda bottles and squeeze most of the air out.

In fact, I have had it keep more than a year in a 80-90% full, not perfectly squeezed 1 liter HDPE bottle. So it is not so critical.

And last but not least, as others have already said, DO NOT EVER BUY "ACCORDION BOTTLES"!!! They are the best way to get any photo chemistry go bad. They fail in every aspect they are designed for. On the other hand, I have had RA-4 developer survive even the accordion bottle test, so don't worry about RA-4.

Newt_on_Swings · May 26, 2011

bleh... I just send it up into the vacuum of space in my rocket after each darkroom session.

Seriously does this even matter? just date and mark your usage, and dump your chems in a timely manner. Its not like your pouring a precious metal down the drain... lol

michaelbsc · May 26, 2011

Newt_on_Swings said:
bleh... I just send it up into the vacuum of space in my rocket after each darkroom session.

Wow!

How do you keep it from boiling at that pressure?

Dave Pritchard · May 26, 2011

Steve Smith said:
What about propane accessories?!

Steve.

Just ask Hank!

polyglot · May 26, 2011

Newt_on_Swings said:
Seriously does this even matter? just date and mark your usage, and dump your chems in a timely manner. Its not like your pouring a precious metal down the drain... lol

You've never tried buying colour chemicals in Australia, have you?

jm94 · May 27, 2011

i have begun my ra-4 printing, which is a shambles at the moment! i mixed the chems into a big 5L PET container... then i poured out my first 1L, then squirted the refrigant into the big container for several seconds, then screwed on the cap, tight.
so the next 4x1L will be ready for me to use when im ready for it the last 3 lots of concerntrate for the developer i left. the blix halves, i mixed as blix for my first run, and stored that 5L in the same manner =] p.s we are actually dumping precious metals down the drain (silver) if we do not remove it first! im saving up all my fixer to try electroplating

Dave Pritchard · May 31, 2011

jm94 said:
i have begun my ra-4 printing, which is a shambles at the moment! i mixed the chems into a big 5L PET container... then i poured out my first 1L, then squirted the refrigant into the big container for several seconds, then screwed on the cap, tight.
so the next 4x1L will be ready for me to use when im ready for it the last 3 lots of concerntrate for the developer i left. the blix halves, i mixed as blix for my first run, and stored that 5L in the same manner =] p.s we are actually dumping precious metals down the drain (silver) if we do not remove it first! im saving up all my fixer to try electroplating

Try it. It is fun. I have removed silver from used fixer with a simple rig consisting of a AA cell, some silver wire, and some stainless steel wire. It is not hard, you just have to look up some diagrams online. I started with silver wire, so the silver would just make the silver wire thicker over multiple uses.

Carbon Dioxide compressed air - good at stopping oxidation?

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