Question on using Inert gas to protect unused Developer

[Steven Ruttenberg]

I am getting a dy nitrogen cyclinder from Prestacycle that is 6CF with regulator. I will do as I did in the Marines when we purged moisture/air from optical systems.

My question is this:

Does anyone have experience with Argon? I have read some interesting things about it and they use it for wine preservation sometimes instead of nitrogen. Price isn't the issue as much as effectiveness. I could go a couple of months with no developing while I take images so I can be effective in the use of the chemicals and not waste.

Looking for thoughts on who prefers what and why. I am perfectly good with dry nitrogen.

[lanactoor]

Dry nitrogen is sufficiently inert at normal temperature and pressures. Argon has the advantage of being denser and thus more effective at displacing oxygen at the exposed surface of the developer (or wine).

[Steven Ruttenberg]

Dry nitrogen is sufficiently inert at normal temperature and pressures. Argon has the advantage of being denser and thus more effective at displacing oxygen at the exposed surface of the developer (or wine).

Interesting. 1 vote for Argon

[koraks]

The necessity of all this depends on the developer. IIRC Steven you are using pyrocat. If this is in glycol, then no purge gas is needed in the first place.

[Jeff T]

Careful with Argon in a unventilated room. It could displace the oxygen in your lungs. Well, actually all inert gases have a risk of asphyxiation. I use Argon for TIG welding.

[Pere Casals]

Does anyone have experience with Argon?

Just use Tetenal Protectan cans, at the end it would be cheaper and way more convenient. Cheaper alternatives would be dust-off or butane spray.

_________________

Argon is better than nitrogen, completely inert and it has a higher density. Butane may even be better than Argon because of density, but it is flamable. Tetenal Protectan contains butane, propane and isobutane: Page 2: https://www.digitaltruth.com/product...ectan-MSDS.pdf

A high density allows to displace up any remaining oxygen in the bottle, with the protective gas forming a layer on the liquid, nitrogen won't do that. Se densities of butane, argon and nitrogen compared to oxygen.

I've argon for TIG, but I use Tetenal Protectan sprays for convenience. I use Protectan only for E-6 concentrate chem, I only mix from concentrate the amount I'm to use, then I fill the E-6 concentrate bottles with protectan. It looks that in this way E-6 concentrate lasts as if it was unsealed.

For BW chem I don't use gas, I keep BW developers inside soda bottles of different sizes that are flexible, allowing to remove air, also that kind of plastic has a barrier effect to contain the CO2 in the drinks, and it also prevents taking O2 from outside air. Of course I label very well the soda bottles with skull and bones.

[interneg]

I could go a couple of months with no developing while I take images so I can be effective in the use of the chemicals and not waste.

In that case you would be better off with a simpler solution: mix fresh chemistry when you need it & batch process. No point in trying to eke out extra life from ageing chemistry. Guaranteed exercise in wasted materials & frustration otherwise.

[Steven Ruttenberg]

Careful with Argon in a unventilated room. It could displace the oxygen in your lungs. Well, actually all inert gases have a risk of asphyxiation. I use Argon for TIG welding.

Nitrogen will do the same thing

[Steven Ruttenberg]

The gas storage is quite cheap for me. One cylinder will last me indefinitely. I develop slides, bw, color neg. Sometimes, it is easier to mix a certain quantity, especially for slide/color neg than to to try to precisely measure out exactly what you need for one session. I have enough individual chemicals for pyrocat to last years too so that is not an issue. It is more the convenience to mix a certain amount and not have to worry about that step each time I want to develop. I am leaning towards Argon. 6CF will last a very long time for what I will do with it.

[Steven Ruttenberg]

This is what I ordered along with a regulator. I have the rest of the stuff to use it. Local shop can fill it up. I got the high pressure 6CF one.

https://www.prestacycle.com/product/...gen-cylinders/