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.

[Tin Can]

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.

Yes, that helps.

Thank you!

[Harold_4074]

Michael R has it right; the thiosulfate will react with oxygen, at a rate partly determined by the rest of the formulation. The sulfite, as an oxygen scavenger, will convert to sulfate. It also stabilizes the thiosulfate against acidity, which is why pure thiosulfate solution will precipitate sulfur on contact with the carbon dioxide in the air. Presumably, there is more going on in TF-5 than these simple reactions; I don't know the formula and in fact still use TF-4, which has a recommended storage life and tray life which are probably based on oxygen permeation of the bottle and solution respectively.

Gas burst agitation creates a lot of air/liquid surface area, and the turbulence will pretty much eliminate concentration gradients, so whatever can happen to fixer in contact with air will happen a lot faster in a burst system than in tanks or even trays.

My worry would be that the degradation would not be gradual enough to trigger the "double the initial clearing time" test until suddenly a batch of film comes out stained, grainy, or otherwise compromised. Exhaustion of things like stabilizers, plasticizers and inhibitors can behave that way.

[Tin Can]

Michael R has it right; the thiosulfate will react with oxygen, at a rate partly determined by the rest of the formulation. The sulfite, as an oxygen scavenger, will convert to sulfate. It also stabilizes the thiosulfate against acidity, which is why pure thiosulfate solution will precipitate sulfur on contact with the carbon dioxide in the air. Presumably, there is more going on in TF-5 than these simple reactions; I don't know the formula and in fact still use TF-4, which has a recommended storage life and tray life which are probably based on oxygen permeation of the bottle and solution respectively.

Gas burst agitation creates a lot of air/liquid surface area, and the turbulence will pretty much eliminate concentration gradients, so whatever can happen to fixer in contact with air will happen a lot faster in a burst system than in tanks or even trays.

My worry would be that the degradation would not be gradual enough to trigger the "double the initial clearing time" test until suddenly a batch of film comes out stained, grainy, or otherwise compromised. Exhaustion of things like stabilizers, plasticizers and inhibitors can behave that way.

Thanks Harold,

I will be getting N2 in 2 weeks and will start using it on TF5 right away. Heretofore I was counting sheets and replacing fixer at a set schedule. I am now certain TF5 or any fixer will degrade faster with Air Gas Burst.

Then I will need to consider how to test in a discernible way the efficacy of N2 and Air on one shot Rodinal. That may be a poor quest.

If N2 cost over time is low enough, I will simply use N2 for all processes. The air compressor simply got me running sooner.

[Mark Sampson]

I won't contradict the chemists, but in the lab where I worked at Kodak we used nitrogen for the developer and air for stop bath and fixer. We (naturally) followed the recommendations engineered (and published) by our colleagues at Kodak Research Labs across the river. I never saw fixer degrade faster than normal- at least it always lasted until the 'square-inches of film' limit, when we replaced the stop bath and fix. All EK products of course...
As I recall, (this was c.1985), gas-burst systems were meant for full-strength, replenished developers and lots of film; not diluted, one-shot methods. But this may make no difference in practice.

[Jim Noel]

"As I recall, (this was c.1985), gas-burst systems were meant for full-strength, replenished developers and lots of film; not diluted, one-shot methods."
Correct. At the college we used N burst with D-23 on a replenishment basis, and air for the fixer. The D-23 was used for a full semester at which time I recovered it for use in total development when maximum increase in overall density and contrast was needed. Since the average usage was on the order of 1200-1500 sheets of 4x5 per month, the D-23 lasted well, but the fixer had to be changed sometimes every other day.
In the final years of using the system, we did not use gas burst for fixing, but had students remove film from hangers and fix in trays. This eliminated problems with under-fixed negatives.

[Harold_4074]

I never saw fixer degrade faster than normal- at least it always lasted until the 'square-inches of film' limit

That sounds entirely reasonable, since there is probably a good margin of safety built into the limit. My guess is that you were using either Kodak Fixer or Kodak Rapid Fixer (or the bulk equivalents--wasn't there something like Ektafix sold in boxed bags?) which was rather different from the TF series of fixers. Anything with sodium thiosulfate to which sulfuric acid is going to be added is probably going to need a lot more sulfite than a "neutral" fixer, which could play into the oxidation characteristics.

This thread has me wondering if the old formulas for fixer test solution are usable with the TF series, and if not, is there a formula that is? My suspicion is that the modern vendors of photographic chemicals, with the possible exception of Ilford, do not do quite as much research and quality control as the old Kodak did, and the published capacities may be extremely conservative. I think that the shelf life of TF4 concentrate is given as something like six months, which seems awfully short, and I know from experience that three-year-old bottles clear film in under sixty seconds, just like new stuff does.

[Michael Kadillak]

If there is one thing I learned in this LF/ULF photographic pursuit of mine is that gas burst is a time tested art form that does not need to be reinvented. Use N2 for development and adhere to what took Kodak decades to perfect - period! When I wrote the Gas Burst Article in View Camera years ago it was after a full two years of attempting to follow Gordon Hutchings Book of Pyro conclusions that were flat out WRONG. I did NOT need special tanks and hangers much to my dismay in believing that Gordon had done his homework which he simply did not. When I gained access to the Kodak Gas Burst article which I have shared freely on this forum the sky opened up. I am up to the largest N2 tank that one can purchase without going into the lease program.

[Tin Can]

Michael, I am not trying to reinvent anything and have not read Gordon Hutchings Book of Pyro.

Once I found the Kodak data I immediately moved in that direction. My Gas Burst set points are identical, but my developer is not. I may go to a replenishment developer system in the future.

I will be using N2 exclusively asap, 2 weeks.

I am curious about your developer. Are you using the same batch for long periods or mixing fresh often? Will you share what you currently do?

Your View Camera Magazine post was key in sending me down this path. There is very little data available. So I am searching for all I can find.

Thank you.

[Duolab123]

I have my copy of Kodak pamphlet E-57, revision 9-70. Says what all of you good folks are saying nitrogen for developer air for the rest. I actually have a BS in Chemistry, not that that makes me any kind of expert. The thing that occurs to me is that if you are using a one shot developer I would think you could very easily get by with air. If Rodinal survives use in Jobo drums with reels, roll or sheet film reels it should survive air bubbles for one cycle.
Also Kodak recommended for B&W 1 sec bursts, 6 times a minute. With Ektachrome in E-3 they say 2 seconds only once per minute.

Having said this our atmosphere is loaded with Oxygen. It amazes me how little air left in a partially full bottle of developer will spoil it. I don't keep partial bottles of stock solutions any more I have a bunch of PET bottles 2,4,8,16,32 oz and fill them to the very top. I have kept XTOL stock for over a year and never had a problem. I just dump the bottle into a beaker then fill the bottle with DI water to make 1:1 Xtol, have used this method for at least 15 years.

[Harold_4074]

I have my copy of Kodak pamphlet E-57, revision 9-70. Says what all of you good folks are saying nitrogen for developer air for the rest.

I'm pretty sure that TF5 was not the fixer of choice in 1970; the chemistry of thiosulfates hasn't changed, but the formulation of fixers has. I wouldn't say that air is bad for agitating fixer, but unless you are talking about an acid, hardening fixer based on sodium thiosulfate, I wouldn't say that it is necessarily innocuous.

Also, there is theoretically a big difference between bubbling fully oxygenated air through developer and putting the same developer into a sealed container with a small amount of air for the same amount of time.

Some testing would be needed to settle the issue one way or the other, but life is short and nitrogen is cheap...

[Michael Kadillak]

I primarily use Pyrocat HD in highly dilute semi stand mode at this stage in my gaseous burst process. I spend considerable time with Alistair Inglis assisting him dial in his tanks in larger formats. Conventional developers just don't get me enough RPM's in print mode.


Michael, I am not trying to reinvent anything and have not read Gordon Hutchings Book of Pyro.

Once I found the Kodak data I immediately moved in that direction. My Gas Burst set points are identical, but my developer is not. I may go to a replenishment developer system in the future.

I will be using N2 exclusively asap, 2 weeks.

I am curious about your developer. Are you using the same batch for long periods or mixing fresh often? Will you share what you currently do?

Your View Camera Magazine post was key in sending me down this path. There is very little data available. So I am searching for all I can find.

Thank you.

[analoguey]

Went through another couple of threads on the topic, post Michael's reply. Loads of Info here, but I get the feeling that even with all that, this is something where experience is needed to actually make (practical) sense of the info. While I'm currently in the middle of rejigging my enlarger light source, (once that's sorted out) this will be the next thing I would attempt.

One question though - does it need only high volume processing for the Gas burst process to pay off?

[Michael Kadillak]

Went through another couple of threads on the topic, post Michael's reply. Loads of Info here, but I get the feeling that even with all that, this is something where experience is needed to actually make (practical) sense of the info. While I'm currently in the middle of rejigging my enlarger light source, (once that's sorted out) this will be the next thing I would attempt.

One question though - does it need only high volume processing for the Gas burst process to pay off?

I say that it is not necessary to only have high volume of processing to make the process pay off. One should take into the consideration a number of other issues into proper context. My particular views on this subject center around both simplicity and repeatability of the process taking out as many variables as possible. With gas burst there is really only one moving part and that is the solenoid valve opening and closing allowing the N2 (or air) into the plenum base. No rotating drums, manual tray or even brush agitation, or dipping and dunking. Once I confirmed that I could use pyrocat in this process I was all in. The Reduced Agitation Process (primarily controlling extreme + and - development) is highly effective in using minimal volumes of pyrocat as well as small quantities of N2. Quite honestly the challenge is not in the process but in finding older 3.5 gallon tanks, plenum/hanger combinations and solenoid valve/timer controller panels. I was fortunate to have scrounged up a number while the getting was good but most of this equipment was likely tossed out when it was not selling. Having the ability to process a large batch is great but not necessary since even smaller process runs make sense.

I did run across an article on the development of Xtol where Kodak used replenishing techniques in their testing and was going to explore and refine this technique further, but found a point where I was pleased at what conclusions I was able to arrive at after a long frustrating journey and pulled off the side of the road to get some results in the done column. I will hunt up that article and post it if anyone is interested. I will continue to reiterate the need for safe recharging of air into the darkroom when using N2 gas burst so a buildup of this inert gas does not fill the darkroom and create an oxygen deprivation working environment. Please BE SAFE!.

[Duolab123]

I sure agree about the Nitrogen is cheap we use these same types of cylinders of Nitrogen at work to pressurize 250 gallon tanks of polyurethane chemicals. They last a long time, If you are using this setup for 30 minutes a day Developer and fix I would venture 1 cylinder would last a year. TF-5 is 58% ammonium Thiosulfate, ie Kodak Rapid fix, it's been this way since G. Eastman was running the show. Kodak F-5 stinks, Kodak F-6 doesn't stink as bad. Both use good old sodium thiosulfate same. Ammonium Thiosulfate is used in I would say almost every liquid fixer formula out there. And I would say not to be rude but fixer chemistry has not changed in over a century, THERE! This outta make everyone go nuts:-) Just my opinion not very humble:) Don't shoot the messenger
Peace!

[Jac@stafford.net]

Regarding the solenoid that releases N2, a super strong current sapper is not necessary.
Electrical hydraulic and water valves can be like the one in your clothes washer: it does
not make a single powerful pull or push of a valve, but vibrates instead.
.

[Tin Can]

Update nearly 6 years later

I never bought N2 cylinder as I don't need it, I do have the correct new valve for N2. I have handled 1000's of N2 tanks in my time at work, in tiny spaces WITH great ventilation at a huge exchange rate, I worried more about knocking the valve off...that is impressive, I saw the movie

Been running on tiny quiet air compressor, just bought a second one so I can have one in DR and my shed. The new one is even quieter, same Brand California Air Compressor (https://www.amazon.com/gp/product/B077CNLPBC/ref=ppx_yo_dt_b_asin_image_o04_s01?ie=UTF8&psc=1)

My process has not changed, 1 Gallon SS covered tanks with air plenum, 4 sheets 8X10, 8 Sheets 5X7, 16 4X5 on KODAK hangers

DIY timer air controller still running

I use Rodinol 1-100, water stop no agit, TF5 only, TF% seems to outlast me, I dump on a schedule. I test TF5 before every use, it clears fast, air bubbles seem to have no effect

Rodinol One Shot exhausts at 20 minutes, I often use 7 to 10 minutes depending on film, all tanks are in water bath at 20C controlled by slow flow HASS Valve

Wash is in same line slow plenum flow

I really like using the system. I hang all films to dry on KODAK double pinpoint hangers over my sink and wait for morning, door shut

ULF is done one sheet at a time in trays

I love my 2X3 sheet film tiny tanks, I even dry the film right in them

[Duolab123]

Update nearly 6 years later

I never bought N2 cylinder as I don't need it, I do have the correct new valve for N2. I have handled 1000's of N2 tanks in my time at work, in tiny spaces WITH great ventilation at a huge exchange rate, I worried more about knocking the valve off...that is impressive, I saw the movie

Been running on tiny quiet air compressor, just bought a second one so I can have one in DR and my shed. The new one is even quieter, same Brand California Air Compressor (https://www.amazon.com/gp/product/B077CNLPBC/ref=ppx_yo_dt_b_asin_image_o04_s01?ie=UTF8&psc=1)

My process has not changed, 1 Gallon SS covered tanks with air plenum, 4 sheets 8X10, 8 Sheets 5X7, 16 4X5 on KODAK hangers

DIY timer air controller still running

I use Rodinol 1-100, water stop no agit, TF5 only, TF% seems to outlast me, I dump on a schedule. I test TF5 before every use, it clears fast, air bubbles seem to have no effect

Rodinol One Shot exhausts at 20 minutes, I often use 7 to 10 minutes depending on film, all tanks are in water bath at 20C controlled by slow flow HASS Valve

Wash is in same line slow plenum flow

I really like using the system. I hang all films to dry on KODAK double pinpoint hangers over my sink and wait for morning, door shut

ULF is done one sheet at a time in trays

I love my 2X3 sheet film tiny tanks, I even dry the film right in them

Hello Mr Can.
I'm over in Iowa, been following your exploits over time. I have 2 gallon tanks with a plenum. I have a bunch of 1 gallon tanks, beautiful stuff. Where can I get gas plenums for the 1 gallon tanks? I would try to fab my own but that's not going to happen. I can't bend the tubing and the gas holes (that's funny) are so tiny.
I have a huge Jobo machine and tanks, but that's no fun. I have a Kodak Gaseous Burst Agitation timer, nos, with the Kodak supplied solenoid valve. I've got a setup for nitrogen too, but I wouldn't use that unless I fiddled with color.

I need a contact at Arkay or similar.

[Michael R]

Hey Duolab123, before you spend all kinds of money on this silliness, consider an expert drum for your Jobo. While not as jet propulsion lab as a nifty nitrogen burst system, if you are truly interested in the quality of the results I am almost certain nitrogen burst development gives poor uniformity in comparison to a Jobo. Just a thought.


Hello Mr Can.
I'm over in Iowa, been following your exploits over time. I have 2 gallon tanks with a plenum. I have a bunch of 1 gallon tanks, beautiful stuff. Where can I get gas plenums for the 1 gallon tanks? I would try to fab my own but that's not going to happen. I can't bend the tubing and the gas holes (that's funny) are so tiny.
I have a huge Jobo machine and tanks, but that's no fun. I have a Kodak Gaseous Burst Agitation timer, nos, with the Kodak supplied solenoid valve. I've got a setup for nitrogen too, but I wouldn't use that unless I fiddled with color.

I need a contact at Arkay or similar.

[Bob Salomon]

Hello Mr Can.
I'm over in Iowa, been following your exploits over time. I have 2 gallon tanks with a plenum. I have a bunch of 1 gallon tanks, beautiful stuff. Where can I get gas plenums for the 1 gallon tanks? I would try to fab my own but that's not going to happen. I can't bend the tubing and the gas holes (that's funny) are so tiny.
I have a huge Jobo machine and tanks, but that's no fun. I have a Kodak Gaseous Burst Agitation timer, nos, with the Kodak supplied solenoid valve. I've got a setup for nitrogen too, but I wouldn't use that unless I fiddled with color.

I need a contact at Arkay or similar.

Omega Arkay, ask for Jeff.

[Tin Can]

Prove it


Hey Duolab123, before you spend all kinds of money on this silliness, consider an expert drum for your Jobo. While not as jet propulsion lab as a nifty nitrogen burst system, if you are truly interested in the quality of the results I am almost certain nitrogen burst development gives poor uniformity in comparison to a Jobo. Just a thought.

[Jim Noel]

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.

N2 is an inert gas and will not combine with photo chemistry to alter it. It is so inexpensive to use it really makes little sense to use air and take a chance on it reducing the efficiency or life of the chemistry.

[Duolab123]

Hey Duolab123, before you spend all kinds of money on this silliness, consider an expert drum for your Jobo. While not as jet propulsion lab as a nifty nitrogen burst system, if you are truly interested in the quality of the results I am almost certain nitrogen burst development gives poor uniformity in comparison to a Jobo. Just a thought.

I have 5 3005 Expert drums. They are fine. But they are a bit of a pain. Washing the film is up and down, or taking it out very carefully, putting it into a Kodak 4A hanger to wash. I have a ridiculous amount of stuff. For 4x5 there's nothing easier than open hard rubber 1/2 gallon tanks. However on this front I have stainless tanks Leedal and Arkay, enough to fill a truck.

Don't get me wrong, it all works! I gave myself a retirement gift of a new CPP3 it's a thing of beauty! I use it a lot for roll film. Believe it or not the 3005 tanks are great for color and black and white prints.

Like I said it all works and it's marvelous, but I really like tanks and hangers. I've got a order to Arkay for a 9 reel basket that's designed for hanging in the 3 1/2 gallon tank, should fit into the 2 gallon tanks.

I think I'm going to start collecting steam engines next, Ha!! I'm nuts but I'm having fun!! I retired 3 years back. I don't know how I managed to make it to almost 62. This is all consuming, and fun.
Best Regards Mike

[Michael R]

Prove it

I don't have a nitrogen burst system so I can only relate my observations, having seen and experimented with many sheet film developing techniques and systems over the years - including several gas burst systems. Most systems and manual techniques are lousy as far as uniformity goes, including techniques that seem at first glance/thought like they should work well. Jobo expert drums produce - by far - the best results. I'm working on trying to duplicate those results manually since I don't have a Jobo machine.

If you are satisfied with your burst system, that's cool. I'm only suggesting to someone who hasn't yet invested in building one, that there are better processing options if one is ok forgoing the engineering coolness.

[Michael R]

I think I'm going to start collecting steam engines next,
Best Regards Mike

Now that sounds interesting :).

Yes I agree fun is a very important part of any hobby so no arguments there!

[Duolab123]

Omega Arkay, ask for Jeff.

Hi Bob, is this a sales person? I definitely need to get with a customer service type.
Best Regards Mike

[Duolab123]

Now that sounds interesting :).

Yes I agree fun is a very important part of any hobby so no arguments there!

Maybe use a Steam tractor, set it in my back yard, run a belt to power my rocking print washer :rolleyes:

[Michael Kadillak]

Hey Duolab123, before you spend all kinds of money on this silliness, consider an expert drum for your Jobo. While not as jet propulsion lab as a nifty nitrogen burst system, if you are truly interested in the quality of the results I am almost certain nitrogen burst development gives poor uniformity in comparison to a Jobo. Just a thought.

I would also like to see that assertion properly defended. Gas burst was the process standard for decades for professionals particularly with C41 and E6 processing. I hope you are not talking about personal experience with gaseous burst because I have seen countless iterations of deviations from highly descriptive Kodak guidelines that went into the ditch for a host of reasons. When gaseous burst is executed properly it is simply marvelous.

[Michael R]

Surprisingly, quite a few professional standards of decades passed, weren't as good as they were supposed to be.

To be clear, I'm not talking about home-built systems. I completely agree that to get the best results possible out of gas burst, dip-dunk etc. these systems must be very carefully designed/executed or else they are potentially junk.

My findings in certain cases ran counter to the conventional wisdom. However disappointment aside, I can't really say I was all that surprised as this is a fairly common thing in photography. For other deep dives I can easily post the findings but in this case I'm not really sure how. I'd have to post a long series of images of all these B&W and colour negatives/chromes done over years (none of them are pictures, just uniformly flashed 4x5 sheets).

Anyhow, to quote Ron Mowrey, "if it works, it works". I'm not trying to convert anyone.

Apologies for sidetracking the thread.

[Duolab123]

Surprisingly, quite a few professional standards of decades passed, weren't as good as they were supposed to be.

To be clear, I'm not talking about home-built systems. I completely agree that to get the best results possible out of gas burst, dip-dunk etc. these systems must be very carefully designed/executed or else they are potentially junk.

My findings in certain cases ran counter to the conventional wisdom. However disappointment aside, I can't really say I was all that surprised as this is a fairly common thing in photography. For other deep dives I can easily post the findings but in this case I'm not really sure how. I'd have to post a long series of images of all these B&W and colour negatives/chromes done over years (none of them are pictures, just uniformly flashed 4x5 sheets).

Anyhow, to quote Ron Mowrey, "if it works, it works". I'm not trying to convert anyone.

Apologies for sidetracking the thread.

As you point out, professionally maintained, control strips, control of pH etc etc. I'm a great dabbler.

[Tin Can]

Please post your evidence anywhere appropriate, we have plenty of armchair quarterbacks that never show an image


Surprisingly, quite a few professional standards of decades passed, weren't as good as they were supposed to be.

To be clear, I'm not talking about home-built systems. I completely agree that to get the best results possible out of gas burst, dip-dunk etc. these systems must be very carefully designed/executed or else they are potentially junk.

My findings in certain cases ran counter to the conventional wisdom. However disappointment aside, I can't really say I was all that surprised as this is a fairly common thing in photography. For other deep dives I can easily post the findings but in this case I'm not really sure how. I'd have to post a long series of images of all these B&W and colour negatives/chromes done over years (none of them are pictures, just uniformly flashed 4x5 sheets).

Anyhow, to quote Ron Mowrey, "if it works, it works". I'm not trying to convert anyone.

Apologies for sidetracking the thread.

[Michael R]

If it involved H&D curves etc. I would gladly post them (as I have in the past) but I'm not about to spend hours trying to photograph sheets of film to post here, particularly since there is no point. I'm not interested in changing your mind, and in the past I have had some bad experiences here when posting explanations/evidence. Sorry. Carry on and just enjoy the process. It ain't worth arguing about.

[Tin Can]

You started the argument...

Goodbye


If it involved H&D curves etc. I would gladly post them (as I have in the past) but I'm not about to spend hours trying to photograph sheets of film to post here, particularly since there is no point. I'm not interested in changing your mind, and in the past I have had some bad experiences here when posting explanations/evidence. Sorry. Carry on and just enjoy the process. It ain't worth arguing about.

[Duolab123]

N2 is an inert gas and will not combine with photo chemistry to alter it. It is so inexpensive to use it really makes little sense to use air and take a chance on it reducing the efficiency or life of the chemistry.

Unless you use a one shot developer like Rodinal. You don't use the system everyday (or in my case every week) and don't want to buy, lease or pay demurrage on an idle cylinder that would sit for 24 months, in my case.

That would be different if my new business "freeE6processing.com" takes off :eek: :rolleyes: OY! DON'T OPEN THE DOOR! OPEN TANKS! :D

[Duolab123]

I may have set in motion a chain of events that we all will regret! I do think I would have asked why the flying school guys only wanted to learn how to take off, and cruise. Not land!
That's the second most important thing for a pilot to know, right?
I'm done.

[Duolab123]

Omega Arkay, ask for Jeff.

Do you have any contact info? All I know of Arkay is they fabricate stainless in Milwaukee. I don't know anything about the company. I have acquired old catalogs, most of catalog numbers are the same.
I will probably get lazy and use the Jobo.

[j.e.simmons]

I was able to get a plenum from an old commercial nitrogen burst system. It’s made for a 3.5 gallon tank and works well with that. It is simply a rather rigid plastic tubing formed into a rectangle with a tube extending up above the top of the tank. It was originally attached to a frame that held it about a half inch above the bottom of the tank.

I don’t see why a similar device couldn’t be made from regular tubing held in place and formed into a loop. I’m thinking the base of an under gravel aquarium filter cut to size would work. It would be tedious but the holes could be made in the tubing with a hot needle or a tiny drill bit in a Dremel.

[Tin Can]

Agree, the new RO tubing is tough stuff and micro drill bits, meaning below #1 are easily obtained these days

It will take trial and error, but by no means as difficult as drilling SS tube

I would want deeper tanks than my one gallon, so I could have more volume for D23 replenished adding N2 for that

Right now 40 ml of Rodinol per gallon is affordable One Shot

[Duolab123]

So I'm putting this on hold. I've got 2 gallon system pretty much ready. I'm working on my studio and finishing room right now. There's always something.

I used the miracle of my Nikon D6 on Monday to take pictures of my flowering Pear tree. The camera sent jpegs to my phone, I pushed a button and a couple nice glossy 5x7 prints came out of my Canon printer. Pretty clear why pros adopted this new technology ��

[Tin Can]

Yes, but many of us have taken The Road Not Taken
(https://www.poetryfoundation.org/poems/44272/the-road-not-taken)

Always have, sometimes a dangerous path. I turned around JIT more than once

and I want to make negs/Sun Prints after the EMP war



So I'm putting this on hold. I've got 2 gallon system pretty much ready. I'm working on my studio and finishing room right now. There's always something.

I used the miracle of my Nikon D6 on Monday to take pictures of my flowering Pear tree. The camera sent jpegs to my phone, I pushed a button and a couple nice glossy 5x7 prints came out of my Canon printer. Pretty clear why pros adopted this new technology ��

[Duolab123]

Yes, but many of us have taken The Road Not Taken
(https://www.poetryfoundation.org/poems/44272/the-road-not-taken)

Always have, sometimes a dangerous path. I turned around JIT more than once

and I want to make negs/Sun Prints after the EMP war

I'm stocking up for the Great Pixel loss. Film is what I use when it's meant to be kept. If it's a playful thing I use digital. I try to keep my electronic images out of the cloud. EMP, it's a matter of when not if. Even if it's not hostile, there's plenty of problems that just happen.

[interneg]

Something else to consider is that Kodak were not terribly keen on gas burst deep tanks without significant additional manual agitation for either E-6 or C-41 - gas and manual agitation for C-41, gas was actively advised against for any roll format for E-6 - rack and tank dip/dunk are fine because they mechanically agitate and gas burst. While the non-uniformity might be less with BW, you might want to consider that the critical development stages in both processes are not that different from BW film. What worked OK for large batch, high throughput BW sheet film processing (with relatively low image quality standards demanded, owing to lack of enlargement/ purposes other than fine-art photographic quality) in the 1940s/50s with relatively much lower technology BW emulsions, may not work as well with more complex, modern structures. Development uniformity was well studied by Kodak etc - hence why they don't recommend stand processing either.

[Tin Can]

I have 3 questions

What do you use?

Do you own a JOBO system?

Have you used Gas Burst?



Something else to consider is that Kodak were not terribly keen on gas burst deep tanks without significant additional manual agitation for either E-6 or C-41 - gas and manual agitation for C-41, gas was actively advised against for any roll format for E-6 - rack and tank dip/dunk are fine because they mechanically agitate and gas burst. While the non-uniformity might be less with BW, you might want to consider that the critical development stages in both processes are not that different from BW film. What worked OK for large batch, high throughput BW sheet film processing (with relatively low image quality standards demanded, owing to lack of enlargement/ purposes other than fine-art photographic quality) in the 1940s/50s with relatively much lower technology BW emulsions, may not work as well with more complex, modern structures. Development uniformity was well studied by Kodak etc - hence why they don't recommend stand processing either.

[Michael R]

Of the methods I looked at, for B&W negative sheet films I found, to my surprise, classic hand shuffling in open trays to be one of the better methods when it comes to development uniformity. It was one of the ways Kodak often recommended, and really can work very well with some practice and care.

Most of the high volume/commercial processes including dip/dunk and gas burst were compromises.

As someone pointed out earlier, these systems had to be pretty carefully designed etc. I suppose back when these things were more commonplace, there were likely some pro labs that had well designed/engineered systems. In more recent times it would undoubtedly have been more sketchy, and I found this to be the case with two dip/dunk labs I sent B&W sheets to. Uniformity was horrendously bad.

Another important thing to consider is how good does good need to be? I was using a very stringent test method - uniformly flashed film. This will obviously reveal even small artifacts which might not be visible or noticeable under photographic conditions. And the more “busy” the photograph, the more non-uniformity you can get away with. I think in many cases (as is often the case with photographic processing - particularly B&W), people just don’t notice non-uniformity unless it is really, really bad. Similar to other technical aspects of the photographic process such as EI, tonality/tone reproduction, developers etc., are we getting what we think we are getting? Often, the answer is no. However when it comes to B&W at least, there is enough flexibility in the end-to-end process that great prints can be made even under a variety of circumstances.


Something else to consider is that Kodak were not terribly keen on gas burst deep tanks without significant additional manual agitation for either E-6 or C-41 - gas and manual agitation for C-41, gas was actively advised against for any roll format for E-6 - rack and tank dip/dunk are fine because they mechanically agitate and gas burst. While the non-uniformity might be less with BW, you might want to consider that the critical development stages in both processes are not that different from BW film. What worked OK for large batch, high throughput BW sheet film processing (with relatively low image quality standards demanded, owing to lack of enlargement/ purposes other than fine-art photographic quality) in the 1940s/50s with relatively much lower technology BW emulsions, may not work as well with more complex, modern structures. Development uniformity was well studied by Kodak etc - hence why they don't recommend stand processing either.

[Michael Kadillak]

Something else to consider is that Kodak were not terribly keen on gas burst deep tanks without significant additional manual agitation for either E-6 or C-41 - gas and manual agitation for C-41, gas was actively advised against for any roll format for E-6 - rack and tank dip/dunk are fine because they mechanically agitate and gas burst. While the non-uniformity might be less with BW, you might want to consider that the critical development stages in both processes are not that different from BW film. What worked OK for large batch, high throughput BW sheet film processing (with relatively low image quality standards demanded, owing to lack of enlargement/ purposes other than fine-art photographic quality) in the 1940s/50s with relatively much lower technology BW emulsions, may not work as well with more complex, modern structures. Development uniformity was well studied by Kodak etc - hence why they don't recommend stand processing either.

As should be the case, factual first hand personal experience as it directly relates to processing results is the only thing that matters. My goodness how far we have come. I can very effectively do stand and semi stand development in gas burst tanks with multiple sheets of film in hangers which was the classic recipe for disaster from Kodak.

[Duolab123]

I've got a mountain of equipment I've accumulated over the last 40 years. I have old Jobo, I have new Jobo. The CPP3, is a very well built machine, with the lift it's pretty straight forward. No where in the very sparse instructions (literally a photocopied sheet) is there adequate discussion of understanding temperature in the tank throughout the process.
The only way it stays at 100 +/- 1/2 °F is if the room and everything else is at 100 F. If I'm working in my darkroom @ 19°C or cooler in winter, even if I prewarm, prewet, have chemistry at temp. The lift is still cold, uncontrolled etc.
The only way for a Jobo to be able to be dead on, would for there to be some sort of closed loop process. That would take instrumentation in the tank, in the lift chute and the appropriate software etc..
I have a Arkay set-up that can handle E6 7 solutions in 2 gallon or C41 up to 4 3.5 gallon tanks. It's all heated, big circulation pump. It's deadly accurate, IF, you follow the Kodak gospel on using hangers, print baskets etc. The old Kodak had you use scrap paper and the hangers, baskets etc to understand what the environment of the darkroom had on temperature.
Only huge masses of liquid can be held relatively constant. You need a water bath to develop roll film in Nikor stainless tanks. My Bearpaw hands will heat up a stainless tank.
For me the biggest issue with big tanks is replenishment, which is impossible without the discipline of control strips and a densitometer.

I don't have the volume of film to do much other than use oversize (larger than required) Jobo tanks, a water warm up presoak (even Jobo is recommending this now) I use 1 liter solution volume. Try to keep everything consistent.
I think this is what Tin Can is doing with one shot, 2 gallon of Rodinal, which I'm going to try at sometime because I love Rodinal, I love XTOL too. With air for the gas in black and white, the Rodinal or something like D-23, seems to be a very workable solution.

I like getting bargains on equipment. Otherwise I would be downstairs right now with my 4x5 hard rubber tanks developing film in, the old days, HC-110 Dilution B.
Peace, stay well.

[Duolab123]

As should be the case, factual first hand personal experience as it directly relates to processing results is the only thing that matters. My goodness how far we have come. I can very effectively do stand and semi stand development in gas burst tanks with multiple sheets of film in hangers which was the classic recipe for disaster from Kodak.

Yeah, you must be doing something wrong if you're getting good results :D:o:eek: