making co2 for chemistry storage?

eli griggs · Aug 27, 2007

I was wondering if anyone here is using vinegar and baking soda to make small amounts of co2 for replacing the air in their chemistry like undiluted HC-110?

If so, what is your method and observations?

Eli

jim appleyard · Aug 27, 2007

I don't think you want to do that. From other posts I've read, the CO2 will combine with the water in the chemistry and make carbonic acid (???, I'm no chemist and I'm goin on memory here).

What you can do is use glass jars for storage and fill up the remaining space with glass marbles, or give a shot of propane (I know, a fire hazzard) into the space.

Or, just use up the chems before they go bad. That means more phototaking, rough, isn't it?

MikeSeb · Aug 27, 2007

NOW we know why the Iranians are enriching uranium--they want to preserve their stocks of HC-110 in case of an embargo!

imazursky · Aug 27, 2007

I think and i could be wrong but Co2 will oxidize developer.
In the past, i have used Nitrogen.
Nitrogen is an inert gas and will not oxidize the developer. It is also heavier than air (oxygen).
It will displace the oxygen in the bottle and create a blanket over the liquid protecting it.

srs5694 · Aug 27, 2007

Another option is to create a (partial) vacuum. I use the Pump-n-Seal, but another option I've seen mentioned is the Vacu-Vin. The Pump-n-Seal works with (relatively) wide-mouthed jars and their original lids; it uses inexpensive tabs that you place over small holes you punch in the lids, enabling them to be vacuum-sealed. The Vacu-Vin is similar in principle, but it uses relatively expensive plugs that are designed for use in relatively narrow-necked wine bottles. Both devices work much like bicycle tire pumps, but they suck air out rather than pump it in.

eli griggs · Aug 27, 2007

I don't think you want to do that. From other posts I've read, the CO2 will combine with the water in the chemistry and make carbonic acid

That's interesting; I have been under the impression for years that co2 was ideal for replacing air in chemistry, using things like canned dust removers, such as Dust Off and those little co2 cartridges for 'air-guns.'

Besides Propane and Nitrogen, what sort of gasses are safe for chemistry?

Eli

Photo Engineer · Aug 27, 2007

Eli;

Carbon dioxide will indeed change the pH of developers and some other photographic solutons.

Carbon dioxide is a weak acid and will form carbonic acid in the water which will neutralize the alkali in alkaline fixers such as TF-4 and also in all alkaline developers.

Don't use it!

PE

Ed Sukach · Aug 27, 2007

For years, now, I've used butane from a BernzOMatic Torch. The torch itself is easily obtainable at Home Depot, etc.,
It is small, easily handled and refillable from BernzOMatic and other butane cylinders used for butane lighters and candles.

It has worked like a charm... a two-three (five?) second burst, and my chemistry is protected.

I still appreciate Ole's help here.

eli griggs · Aug 27, 2007

Now that I know co2 is verboten! it looks like butane or propane is the best choice for the moment. It's cheap, available everywhere and, as I would rather use a gas than other methods, a good fit.

I have occasionally used marbles in the past, but I'd rather not and a vacuum system is more likely to see use in the kitchen than the darkroom.

Thanks for the feedback everyone, all of it is helpful.

Eli

Photo Engineer · Aug 27, 2007

Use nitrogen. A cylinder is about $25 and if you buy the tank it is about $100. The valves/regulators are about $150.

This setup, for about $250 US will last the average person a lifetime with one tank of nitrogen.

PE

Alex Hawley · Aug 27, 2007

Photo Engineer said:
Use nitrogen.
PE

Yep, nitrogen. Its the standard for use across many various industries for making an inert atmosphere.

imazursky · Aug 28, 2007

I would recommend nitrogen instead of butane.
There is always the chance of combustion. Static or a flame.
My darkroom is in the same room as my HVAC.
With my luck.......Kaboom!! if i used butane.

You can also purchase smaller Nitrogen cylinders. They are less expensive and the valves are cheap on ebay.

gainer · Aug 28, 2007

Butane is obviously inflammable.

Anyone who has been using CO2, upon finding that it can change pH of the solutions, but has seemed to do no harm, must wonder what is the need to use anything but air! Could it be much worse? How long will it take to show its worseness?

Various other schemes have been used. Accordion style collapsible containers aren't much good. They can only collapse so far. Small sealed bottles each filled with one dose are good if you are sure that the solutions are themselves stable in the absence of air.

pkrentz · Aug 28, 2007

Gas sealing

I don't know how effective it is but I always just exhaled into the bottle. Its cheap too!Pat

Photo Engineer · Aug 28, 2007

Pat;

Ineffective and perhaps harmful to the solution.

PE

eli griggs · Aug 28, 2007

Accordion style collapsible containers aren't much good.

Isn't that the truth! I bought a bunch of those accordion bottles years ago and never found them to be anything but a pain. Maybe I'm bent, but I lost so much chemistry while trying to expel all the air, that I would have rather had let it go bad than deal with the mess and aggravation.

As far as buying nitrogen, I do have an empty medium sized tank and gages already, it's just that the cost of the gas seems way out of proportion to the savings in chemistry. I suppose I'll eventually do this, but I would rather spent those few dollars on film or chemicals to make more chemistry. I guess this means I'm not only near sighted but short sighted as well.

Eli

Photo Engineer · Aug 28, 2007

The best storage bottles I have ever found are the Jobo bottles sold in 1/2, 1, 2 and 5 liter sizes. Seems like developers keep forever in these things, even without a nitrogen head.

PE

Dan Henderson · Aug 28, 2007

Please follow PE's suggestion and use nitrogen rather than a flammable gas such as butane or propane. Propane is under pressure to stay liquified and be stored efficiently. Therefore it is always looking for an opportunity to escape its container. It is heavier than air and accumulates in low places, then just waits for an ignition source (pilot light, electrical switch, static charge, etc.) A propane explosion is no way to remodel the darkroom, and your wife/husband will be really pissed if you blow her/his house up in the process. I'm not as versed with butane and propane, but I believe that it behaves badly as well.

Ed Sukach · Aug 28, 2007

gainer said:
Butane is obviously inflammable.

True. So was Tetenal's "Protectan" spray - specifically intended for photographic chemistry preservation - composed of a mixture of butane and propane. I've used Protectan for years with great success - but it has not been exported to the United sates for quite some time.[/QUOTE]

donbga · Aug 28, 2007

eli griggs said:
I was wondering if anyone here is using vinegar and baking soda to make small amounts of co2 for replacing the air in their chemistry like undiluted HC-110?

If so, what is your method and observations?

Eli

Specifically for HC-110 concentrate you really don't need to put any nitrogen or other gas in the storage bottle. The HC-110 will stay good in a partially filled bottle for a very, very long time even though it will change color - darken.

donbga · Aug 28, 2007

jim appleyard said:
or give a shot of propane (I know, a fire hazzard) into the space.

Good grief, we're talking about preserving chemicals from spoilage not making an IED!

pentaxuser · Aug 28, 2007

pkrentz said:
I don't know how effective it is but I always just exhaled into the bottle. Its cheap too!Pat

I've exhaled into developer after drinking whisky or even whiskey if I am desperate. It did nothing for landscapes but in all the people shots they came out smiling and mellow looking on the negs.

pentaxuser

gainer · Aug 29, 2007

The human body can make either noninflammable or flammable gases. I watched a demonstration of that in a basic training barracks about 60 years ago after a meal with plenty of GI pork and beans. One guy would yell "I've got one coming" and another would hold a lit cigarette lighter at the seat of his problem, and directly we saw a marvelous jet of flame.

So, you don't really have to but either CO2 or butane. I don't recall it smelling any better for the burning.

jim appleyard · Aug 29, 2007

donbga said:
Good grief, we're talking about preserving chemicals from spoilage not making an IED!

The last time I mentioned to put propane/butane in a bottle of chemistry, I was "reminded" that it was/is a fire hazzard. Just doing a little CYA!

pnance · Aug 30, 2007

I agree with Ed Sukach, in the old days I used a product called Prolong, I'm not sure what it was, but it was probably propane or butane. In Europe, and occasionally in the US you can get Tetenal's Protectan, also propane/butane. You pay 5 to 10 bucks for a very small can of the gas, Home Depot, etal, sell the Benzomatic tanks for much less. You only need to use a small amount, the heavy gas will cover the surface of the liquid. I find it greatly increases the lifetime of developers.

Yeah, I know it could be a fire hazard, but like a lot of the chemicals in the home (much less the darkroom) used reasonably it is safe. If you're a klutz, I wouldn't recommend it. Another reason not to smoke.

making co2 for chemistry storage?

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