Inert gases for E6 chemical storage

[ZoneIII]

I started processing my own E6 film again last year because local labs closed and I don't like sending film out for processing. Even a large lab in Chicago ruined the last film I sent out. ( It had classic signs of chemical exhaustion and/or contamination.)

Years ago, I got a large stock of an inert gas sold by Beseler that I used for partially full chemistry bottles but I am almost out of that supply. Now that I'm doing E6 again, I want to find a reasonably priced source of inert gas that is readily available. I am using Kodak 6-step chemistry (one-shot) and I sometimes go a month or two between processing sessions. I am mixing the chemicals as I need them rather than mixing the whole 5 liters so oxidation is not a problem with the mixed chemicals because I use them right away. But I would like to shoot some inert gas into the concentrate bottles.

I know about marbles and using many small bottles. I may, in fact, resort to marbles if I can't find a readily available source of inert gas. But I really would like to find a substitute for the Beseler gas. I also know that inert gases are sold for wine storage and that's an option but, from what I can tell, they are sold in very small cans and they are expensive... probably because anyone who would buy them is also probably a wine connoisseur with money to burn.

I have also heard suggestions to use butane or propane. I remember reading a post somewhere where someone who responded to the butane suggestion almost had a heart attack. I know very little about chemistry but I don't think propane is an inert gas but if it will do the job (prevent oxidation) without causing any other problems, I would use it. (The risk really isn't anything to worry about with a little care and common sense.)

Anyway, can anyone suggest a type of inert gas that will do the job and is readily available?

Thanks

 

[Photo Engineer]

You can buy an empty tank for Nitrogen for about $200 or less and have it filled for about $30. The reducing valve for the top is about $120. One 4 ft tank will last you just about a lifetime!

PE

 

[Bob-D659]

You normally use CO2 for wine storage, problem is it isn't inert and dissolves in the water creating a very weak acid. Propane and butane are probably non reactive with photo chemicals, but heavier than air and REALLY FLAMMABLE. Bad news in a small darkroom.

I second the purchase of a tank of nitrogen and a regulator.

Just head off to a local welding supply place, they will have everything you need.

 

[MikeSeb]

What about Dust-Off or one of the other brands of dust-removal spray? They are supposedly inert. I use this for the very purpose you describe, and have not yet discerned any problems from it.

 

[Bob F.]

Argon in disposable tanks is available from arc-welding suppliers (locally about 12 GBP each). Get a regulator for the disposable cylinders while you are there. I found that 4mm electrical insulation sleeving makes good tubing but probably the welding shop can supply the proper stuff...

 

[resummerfield]

You can buy an empty tank for Nitrogen for about $200 or less and have it filled for about $30. The reducing valve for the top is about $120. One 4 ft tank will last you just about a lifetime!

PE

I use the Nitrogen tank as PE suggests, and couldn't be happier.

Another suggestion for an inert gas would be Argon, although it is more expensive that Nitrogen. But the disposable tanks that Bob F mentions are something that I've never seen here in the US, at least not at my regular welding supplier.

 

[nickandre]

why don't you fill the bottles? I went to a replenishment system because when I mix a liter of C41 developer I get 200 ml extra replenisher after making the working solution from the replenisher. Then when I process a roll of film I dump a bit and top it off with replenisher. Even in plastic bottles when they're completely full they last a while. I've had my C41 liter for a month and it's just starting to darken.

 

[Bob F.]

Ah, thanks for that info. I just did a couple of searches on the auction site for "disposable argon" and restricted the search to USA and UK. The USA search came up with zero finds (ditto Canada) and the UK one came up with 18... Ho hum... Forget that idea in the US and Canada at least. Rest of Europe?

At least I know they are not a N. American item now!

 

[Aurum]

I think the Americans go for refills / exchanges rather than the small disposible bottles that I can get my hands on in Machine Mart or Hellfrauds.

ZoneIII is in Illinois, so his sig says Dead Link Removed

 

[Photo Engineer]

Argon is way overkill due to expense and rarity compared to Nitrogen.

PE

 

[johnnywalker]

What about Dust-Off or one of the other brands of dust-removal spray? They are supposedly inert. I use this for the very purpose you describe, and have not yet discerned any problems from it.

I do this as well. Any chemists have some thoughts on it?? Like does it work?

 

[ZoneIII]

Thanks for the responses, folks. They're a big help.

Nitrogen would be O.K. except that it would be overkill for my purposes. One small can of the old Beseler stuff would last me for a few years. (I think it was called XDL or something like that. I just don't want to run down to the darkroom right now to check.) So spending a couple hundred dollars for nitrogen in tanks would be a bit too much for my uses. However, it would be a good solution if I was running a lot more film. In fact, I have seen nitrogen pumps for about the price mentioned in this tread for the tanks and I could produce an endless supply of nitrogen with one.

MikeSeb... I have heard of people using Dust-Off too. If it is an inert gas, that would be the perfect solution. I appreciate your reply because I had forgotten all about that possibility. Can anyone confirm that Dust-Off is an inert gas?

Tiberiustib2..... I don't want to get into replenishment at this time. I want to go one-shot and just use a blanketing gas in the concentrate bottles after mixing just the amount of chemistry that I need for the job at hand. If I was processing a lot more E6 film and doing it on a more regular basis, I would probably replenish as you suggest. I tend to shoot color in bursts... on trips, etc., but I shoot b&w all year long. That being the case, I think it's better for me to keep the concentrates at full strength and use an inert gas to prevent oxidation because they will often be sitting unused for weeks or even a couple months sometimes.

 

[amuderick]

I use Dust-Off. It is cheap. It works. Dust-Off contains difluoroethane. Pretty inert. Not quite Nitrogen or Argon but more than sufficient for a few months of storage.

 

[ZoneIII]

A quick search on Wikipedia shows that Dust-Off is "Difluoroethane, also called simply difluoroethane, R-152a, or HFC-152a, is a chemical compound composed of carbon, hydrogen, and fluorine. Its molecular formula is C2H4F2."

I also learned that Dust-Off now has a "bitterant" added to it to discourage people from inhaling it to get high.

Are there any chemists here who know if difluoroethane is an inert gas or, even if it isn't, would it be effective for the application discussed here. Of course, the bitterant may be a problem too but it would probably be difficult to find out what that is.

 

[Photo Engineer]

We don't know what the "bitterant" is!

I know that Nitrogen is inert and cheap. Argon is inert and expensive. Both are probably better than most anything else.

PE

 

[Kirk Keyes]

I have a nitrogen tank and it works great. I also use it to exclude air from my Jobo tank when using pyro-type developers, and it works great for that too.

Dust-off will work as well, but it's more expensive than the N2 tank in the long run.

 

[AgX]

Argon is way overkill due to expense and rarity compared to Nitrogen.

I don't think it is as simple as that. At least if you don't want to have a large tank in house.
Over here there do not exist 1L N2 bottles. Thus one would have to buy a 1L CO2 tank, repaint it etc., have a valve adapter machined to comply to the NO2 system and, most difficult, have to find a company willing to flush and fill that non-standard tank.

Anyway, independant of any bottle size, for an amateur user the tank and and valves would probably mean the greater share than the gas itself.


Forming gas has been adviced somewhere else. But this is not even flammable, as Propane/Butane, but stated as highly explosive, even to be ignited by strong oxidants.

 

[Trond]

I top up my chemical bottles with butane/propane. Unless you have an open flame close by when you top up or open the bottles, I can't see how using butan/propane can be much of a hazard.

Tetenal even has a product called Protectan, which is a mixture of butane/propane just for this purpose.

 

[Mike Wilde]

Private Preserve

sold in better wine stores. prevents oxidation by blanketting the surface of a liquid. In our case developers etc, and not wine or scotch.

 

[Photo Engineer]

I don't think it is as simple as that. At least if you don't want to have a large tank in house.
Over here there do not exist 1L N2 bottles. Thus one would have to buy a 1L CO2 tank, repaint it etc., have a valve adapter machined to comply to the NO2 system and, most difficult, have to find a company willing to flush and fill that non-standard tank.

Anyway, independant of any bottle size, for an amateur user the tank and and valves would probably mean the greater share than the gas itself.


Forming gas has been adviced somewhere else. But this is not even flammable, as Propane/Butane, but stated as highly explosive, even to be ignited by strong oxidants.

Many chemical supply houses and some welding shops here sell the 1 L tanks for most gases. Since a larger tank will last virtually a full lifetime, one tank for $30 will pay for itself. You can also rent the equipment and pay a monthly or yearly charge.

But, no matter which way you go, I don't suggest Argon. It is a rare expensive gas. Neon might be cheaper in the long run. IDK. It is more readily available than Argon in some areas due to its use in signs.

PE

 

[ZoneIII]

"I top up my chemical bottles with butane/propane. Unless you have an open flame close by when you top up or open the bottles, I can't see how using butane/propane can be much of a hazard.

Tetenal even has a product called Protectan, which is a mixture of butane/propane just for this purpose."

Thanks, Trond. I totally agree with you about safety not being a big issue as long as basic common sense is followed. Are you saying that you use butane or propane or a combination of them? Also, have you verified that they will do the job discussed here?

Also, thanks for mentioning Protectan. I'll check that out.

 

[ZoneIII]

For anyone else interested in this topic, here's something that I found in a Photo.net thread. It's a quote from Jobo USA.

"All color chemistries need protection form oxidation. You can do this by putting them chemistry in collapsible containers or by displacing the air in the bottles with inert gas. We used to carry Protectan but Tetenal no longer ships it to us. There are other brands on the market. Do not use the Argon gas used for wine storage. We have had cases of developer going bad when this product is used."

 

[Photo Engineer]

Argon gas is totally inert for all practical purposes. It, along with Nitrogen are virtually ideal for storage, but Nitrogen is less costly.

All inert gases are suffocants, that is they can cause loss of consciousness and death in confined areas. They must be used with caution. Butane and Propane are flammable gases and also form explosive mixtures with air. As such, I restrict use of them in case of a static spark which could start a fire.

Use any of these you wish, but being a chemist, I prefer Nitrogen. Kodak has suggested this for years.

PE

 

[AgX]

I agree with Trond that the typical volume of a flammable gas used as protective gas by us is not that hazardeous. And think of all that hairspray that is used in rooms with perhaps a burning candle around...
What makes me dislike Propane/Butane is rather the odourant.

But we shall keep aware of our foolishness, or mine... I once repaired some Propane burner at home. Having finished I left having closed the burner valve, but forgot to close the main valve. Should have been safe anyway. But on my return I realized that I forgot about that open pilot flame valve, through which quite some gas must have leaked meanwhile.

Use what you think being apt but use your common, or even better, sense.

 

[Rob Landry]

An easier method...

Hate to sound like a broken record again but, freeze 'em!

- Mix the full 5L kit the 1st time you process

- separate into plastic water bottles (I use 500ml bottles to leave room for expansion)

- place in freezer (I use a deep freeze)

- done

When you're ready to process, pull from freezer and thaw. No more time spent mixing chems and playing with graduates EVERY time you wanna process a quick roll or 2.

Read this thread if you'd like more info:

(there was a url link here which no longer exists)