Inert gases for E6 chemical storage

[AgX]

In case of having a problem with a rather high pressure stream of inert gas, as Tim described, perhaps a `bubble stone´ intended for aquarium oxigenation might be an outcome. Just an idea.

 

[gatewaycityca]

An inert gas that is cheap and readily available? Sure...helium!

I've seen small tanks sold at Walmart and Costco for around $20. I don't know how long that would last for you, but you could try. I've actually done some experiments with inert gasses. One of the other hobbies I'm into is experimenting with high voltage, and I've made homemade vacuum and discharge tubes. Helium was very easy to work with, and it also seemed to leak slower. So it might not be a problem if you didn't have a *perfect* seal. Maybe because it has a larger molecule size? I don't know exactly why, but I did notice different characteristics that I didn't see with other inert gasses.

And yeah, don't use CO2...it's not an inert gas.

 

[Bob F.]

I think helium will only form a blanket over the chemicals in Australia and New Zealand...

Surely helium with an atomic number of 2 has a very small molecular size - possibly the smallest, as hydrogen mainly exists as H2 (on Earth anyway)? Resident chemists feel free to correct me there - it's been a few years since I did O-level chemistry at school (so many, they stopped doing O-levels decades ago...).

 

[Photo Engineer]

Helium is not a real good choice. It is so small a molecule that it easily is lost from containers due to diffusion either collapsing the container or being replaced by air. It is good enough if you don't mind replenishing it all the time though, say on a weekly basis.

Hydrogen is explosive in air and exists mainly as water.

PE

 

[keithwms]

I would think that dry nitrogen would be about as good a choice as some of these more pricey and more inert options. With dry N2 you can afford a UHP lecture bottle, keep it at an overpressure, and flush it out every now and then. At low temps, and if you use a desiccant to take care of any residual moisture when opening and closing the fridge, then I doubt the inertness matters so much, frankly.

I agree with Ron that the leakiness of He makes it a not-so-good and pricey choice. Ar is nice but I doubt that it really has an advantage relative to N2, as long as temps are low.

I worry a little bit about complete dryness of the storage gas. At some point charge buildup may become a concern with IR and high-speed films. It's not 100% clear to me that you really want superdry conditions for IR and high speed films; I can imagine gradual charge buildup from background ionizing radiation. So I am actually not sure that a completely inert buffer gas would prove better for those kinds of films, for very long term storage. Probably not a heck of a lot you can do about it though- just use the stuff fresh.

Probably a bigger issue, though, is that when something is completely desiccated, if you then expose it to ambient, moist air it will suck up moisture like a sponge. So bringing things up to temp in dry air is probably the best thing one can do.

 

[Wayne]

Again, the only thing I would worry about is the pH effect of the carbon dioxide gas in the mix.

PE

Do you think the C02 would have an adverse impact on the pH of silver dye bleach concentrates? It comes in 3 parts and I was going to use the wine preservative-till I read this thread.

Wayne

 

[Photo Engineer]

Wayne;

IDK about CO2 and the dye bleach solution. If anything, CO2 would raise the pH of that one and impair its working properly, but that is just a WAG. Sorry.

PE

 

[keithwms]

I would assume that CO2 under pressure could eventually develop some partial pressures of of CO and O2, particularly if catalytic metal particles are present. I imagine CO2 chemisorbing on the metal and then dissociating and recombining... But this effect should not matter at low enough temps and pressures and in the absence of (UV) light though. What I am talking about is probably irrelevant in a fridge or cool room.

(N.b. this is a physicist waving his hands abotu chemistry so :rolleyes: take it with a grain of salt...)

 

[Aurum]

Carbonic acid wikipedia

From that link, atmospheric pressure CO2 has the potential to take DI water down to around pH 4 or thereabouts.

 

[Photo Engineer]

Carbonic acid wikipedia

From that link, atmospheric pressure CO2 has the potential to take DI water down to around pH 4 or thereabouts.

But the Dye Bleach solution for Ilfochrome is about pH 1 - 2, so what does CO2 do to that? That is what I cannot answer. But, it might just raise the pH for all we know right now.

It has little likelyhood to disassociate into CO and byproducts though.

PE

 

[bdial]

FWIW, I just got a confirmation via email, from VinyardFresh, that their product has no CO2.

 

[Richard Harris]

just came upon this thread, haven't used apug for ages, sorry. I couldn't believe Bob F's reply. I use welding argon from a DIY store, I use 4mm electrical sheathing for the delivery tube. There's a coincidence. I use green and yellow earth sheathing but have all colours. Bob F, can you tell me what colour you're using so I can rid my self of this annoying lack of exclusivity?
I tried butane from blow lamp cylinders but had oxidation, so went the extra step with argon. Driving of the air is not a science so it's difficult to know if you have failed in the process or it's the gas that isn't preventing oxidation. The plastic bottles that most chemicals come in do not seem to reseal well so I always decant large quantities in to 250ml beer bottles and crown cork them. I then keep the partial filled bottles covered with the argon. No problems for me even when using very small volumes. I agree that CO2 is likely to give you a weak, acid, fizzy drink style developer. Probably tastes rubbish too, try it with the Kids?
Richard.

 

[Bob F.]

just came upon this thread, haven't used apug for ages, sorry. I couldn't believe Bob F's reply. I use welding argon from a DIY store, I use 4mm electrical sheathing for the delivery tube. There's a coincidence. I use green and yellow earth sheathing but have all colours. Bob F, can you tell me what colour you're using so I can rid my self of this annoying lack of exclusivity?

<snip>

Richard.

To allow you to make your life whole again, I am willing to reveal that I use the green and yellow earth insulation. I hereby promise not to buy any other colours.

 

[Richard Harris]

Thanks Bob, I'll cut myself some blue sheathing tonight.
regards etc,
Richard.