Gas Burst Chemistry Oxidation Questions

[Tin Can]

As some know I am trying Gas Burst development.

I am not a chemist and wonder about degradation of developer and fixer from Gas Burst operations. Advice, thoughts?
I observe most call the process Gas Burst, not N2 Gas Burst and all systems I have researched have 2 pressure systems, one N2 and one compressed air.


Specifically, I am using compressed air with one shot Rodinal @1/100 10 minutes. 55-10 second off, 1 second on cycles. It seems to me that one shot developer does not need N2 gas as the developer will last the cycle.

I am more concerned about TF5 Fixer as I reuse it from a 4 gallon tank and test with film for clear speed before each use. Plenty of scrap X-Ray around here.

Will my rather complete aeration of TF5 with compressed air degrade it quickly? Am I contaminating or weakening my storage fixer tank reserve? I use 1 gallon out of 4 and dump it back in.

I suppose I will find out empirically.

Will I get longer usage from TF5 or any fixer by using N2 for Gas Burst?

In the future I may go to a developer replenishment system. Will I really need N2 for Gas Burst. Or not?

Theorists and user input highly desired.

Thanks in advance.

[Michael Wesik]

Hi Randy,

Alistair Inglis is a wonderful fellow who makes gas burst systems and he may be of some help to you: http://www.alistairinglis.com/

Best,

Michael

[Peter De Smidt]

Randy, I've never heard of fixer being affected by oxygen. In color processing Blix (Bleach + Fix) actually requires oxygenation in order to work effectively. I'm not even close to being a chemist, though. You might ask Ron Mowry (Photo Engineer) over at Apug. Lynn Jones, who's a member here, might also know. He was responsible for setting up gas burst systems for developing movie film. I'll send an email off to an acquaintance of mine. He was a project manager in the BW division at Kodak.

[Tin Can]

Hi Randy,

Alistair Inglis is a wonderful fellow who makes gas burst systems and he may be of some help to you: http://www.alistairinglis.com/

Best,

Michael

I hesitate to ask Alistair anything, especially his recomended processes.

I respect his IP rights and if he wanted to share more, he could on his website.

I am not his customer. I am DIY, relying on members here and historical data as I find it.

I'm in the ballpark, I just need to learn my game better.

[Tin Can]

Randy, I've never heard of fixer being affected by oxygen. In color processing Blix (Bleach + Fix) actually requires oxygenation in order to work effectively. I'm not even close to being a chemist, though. You might ask Ron Mowry (Photo Engineer) over at Apug. Lynn Jones, who's a member here, might also know. He was responsible for setting up gas burst systems for developing movie film. I'll send an email off to an acquaintance of mine. He was a project manager in the BW division at Kodak.

Thx. I need to speak to my chemist in Chicago.

[Bob Salomon]

Randy, I've never heard of fixer being affected by oxygen. In color processing Blix (Bleach + Fix) actually requires oxygenation in order to work effectively. I'm not even close to being a chemist, though. You might ask Ron Mowry (Photo Engineer) over at Apug. Lynn Jones, who's a member here, might also know. He was responsible for setting up gas burst systems for developing movie film. I'll send an email off to an acquaintance of mine. He was a project manager in the BW division at Kodak.

Afraid Lynn is no longer with us.

[Michael Wesik]

I hesitate to ask Alistair anything, especially his recomended processes.

I respect his IP rights and if he wanted to share more, he could on his website.

I am not his customer. I am DIY, relying on members here and historical data as I find it.

I'm in the ballpark, I just need to learn my game better.

Totally your prerogative.

When I used gas burst it was recommended by several people to use nitrogen and not compressed air. I can't remember the explanation.

[Peter De Smidt]

Afraid Lynn is no longer with us.

I'm very sorry to hear that. Bob, thanks for letting me know.

[Tony Lakin]

It's nitrogen for developers and air for bleach and fix.

[Michael R]

Thiosulfates are more stable in air than say developing agents, but they do oxidize. This is one reason why even neutral (eg TF-5) and alkaline fixers contain sulfite to scavenge oxygen. In general, plain air is not the best idea for gas burst agitation in a B&W process. If you want maximum longevity out of your TF-5 with a re-use regimen, nitrogen would be the way to go. Alternatively if you stick with air, test your fixer at regular intervals. Using air will accelerate oxidation, but how much faster, we don't know. It may or may not make a meaningful difference in how long you normally run a batch of TF-5. All you can do is monitor it.

Hope this helps.