41 replies to this topic

[TxStars]

I forget who it was, but they had modified an old school pressure cooker to be their hypering chamber..

Which when you think about it is an easy way to get a large sealable chamber cheap.

[Todd N]

I going to retry an experiment I did years ago. That post I mention where a chemist used to hyper rolls of techpan at his work, I recall he stated he used a desiccating bell. That would require lower pressure than atmosphere to maintain the seal. I bought a simple vacuum chamber that is used for degassing and tried this once and it didn't seem to work all that well. And since I had the Lumicon chamber there wasn't a need to pursue this. I may have not hypered  long enough. I will try this again and report back. It should take about a week or so. 

 

 

 

 

I redid this low vacuum test and it seemingly work out well, but I don't know if it can achieve the same optimal results as normal hypering methods. I used a small 1.2 quart degassing vacuum chamber:

https://bacoeng.com/...um-chamber-part

 

As it turns out from my testing, Fomapan 400 has a similar hypering time to Techpan but lower temperature. A slight vacuum has to be maintained to keep the seal. I think there may be slight leakage over time as the pressure valve indicated but it may be temperature fluxuations. A dark cloth was used to cover the transparent acrylic lid. 

 

 

Fomapan 400
Vivtar v3800N 50mm @f/5.6
Exopsure: 4min
Lumicon H-alpha filter
Dual red astronomy light on end table facing room corner
Ilford Microphen
Top Image: Untreated
Bottom image: H2 hyper in degassing vacuum chamber
minus 7 in/HG, 6 days at room temp.(approx 68F)

 

https://www.flickr.c...57697664120191/

 

It can be further hypered so, I put it back in the chamber for another round. But I have to drop this testing after this since I'm getting low on gas. At least this is a starting point if you consider to pursue and refine this approach. I would recommend trying to build the PVC chamber from the webpage I previously uploaded. It would be cheaper and the advantage of using higher pressure for shorter hypering times. These low temperature and pressure hypering times could turn out to be too inconveniently long. 

[xonefs]

Thank you.  That's interesting.

 

I managed to find a lumicon hypering setup here. he didn't think it was complete and I'm not sure what I will need to get it working. I will need an N2 tank at least I'm sure... I haven't received it yet but in any case it was a very reasonable deal. I think he sent the forming gas... this pic is from seller:

 

 

 

Edited by xonefs, 05 March 2023 - 05:07 PM.

[TxStars]

Jason,

 Yes that is a forming gas cylinder in the image.

You will need to buy or build a temp regulator if you plan on using the heating strip.

Without it the strip just go's to max which will heat fog any film in the chamber.

You may also want an electric vacuum pump b/c the hand pumps are a PITA

[Todd N]

Thank you.  That's interesting.

 

I managed to find a lumicon hypering setup here. he didn't think it was complete and I'm not sure what I will need to get it working. I will need an N2 tank at least I'm sure... I haven't received it yet but in any case it was a very reasonable deal. I think he sent the forming gas... this pic is from seller:

 

 

 

 

Jason,

 Yes that is a forming gas cylinder in the image.

You will need to buy or build a temp regulator if you plan on using the heating strip.

Without it the strip just go's to max which will heat fog any film in the chamber.

You may also want an electric vacuum pump b/c the hand pumps are a PITA

 

Oh, I forgot to mention this. I use Inkbird temperature controller:

https://inkbird.com/...troller-itc-308

 

Along with Best Value Vacs heating pad:

https://shopbvv.com/...igital-heat-pad

 

The heat pad is regulated to a set temperature, but it is only respective of the heating pad. There may be a difference to what it is set at and the actual temperature of the hypering chamber; It will be lower. That's why I use in conjunction with it the Inkbird unit which does and the probe fits nicely in one of the holes on the lid where the thermometer goes.. I ended up buying the heating pad since the original heating tape failed soon after I acquired it. The heating pad can't get to the higher temperatures like 50F but we have been over why that is likely not a good thing anyways. The heating pad will get the chamber to around 45C. Then I cover the heated chamber with a towel and cover the whole apparatus with a stryrofoam cooler. If the towel makes you a bit nervous then you can use apprpriate insulation. Again, if you are going to use forming gas you will have to heat the chamber otherwise it may not hyper in a reasonable amount of time; I have never read or seen examples this way. You can hyper at room temperature or use heat with pure H2 to shortand the time only for B&W film. If you eventually try color film you have to use a forming gas mixture; The color layers won't evenly hyper in pure H2.

Edited by Todd N, 05 March 2023 - 10:56 PM.

[xonefs]

Oh, I forgot to mention this. I use Inkbird temperature controller:

https://inkbird.com/...troller-itc-308

 

Along with Best Value Vacs heating pad:

https://shopbvv.com/...igital-heat-pad

 

The heat pad is regulated to a set temperature, but it is only respective of the heating pad. There may be a difference to what it is set at and the actual temperature of the hypering chamber; It will be lower. That's why I use in conjunction with it the Inkbird unit which does and the probe fits nicely in one of the holes on the lid where the thermometer goes.. I ended up buying the heating pad since the original heating tape failed soon after I acquired it. The heating pad can't get to the higher temperatures like 50F but we have been over why that is likely not a good thing anyways. The heating pad will get the chamber to around 45C. Then I cover the heated chamber with a towel and cover the whole apparatus with a stryrofoam cooler. If the towel makes you a bit nervous then you can use apprpriate insulation. Again, if you are going to use forming gas you will have to heat the chamber otherwise it may not hyper in a reasonable amount of time; I have never read or seen examples this way. You can hyper at room temperature or use heat with pure H2 to shortand the time only for B&W film. If you eventually try color film you have to use a forming gas mixture; The color layers won't evenly hyper in pure H2.

thanks that looks perfect for a temp regulator. I guess I can see if the original coils work.

 

thoughts on hypering loaded into canisters? I know there was talk of people doing that and it might be easier. I would like to load a 10 shot roll maybe

 

 

edit: any recommendation on an inexpensive electric vacuum pump?

Edited by xonefs, 06 March 2023 - 12:30 AM.

[Todd N]

thanks that looks perfect for a temp regulator. I guess I can see if the original coils work.

 

thoughts on hypering loaded into canisters? I know there was talk of people doing that and it might be easier. I would like to load a 10 shot roll maybe

 

Hypering in cassette was common. I bought hypered Techpan direct from Lumicon and I would assume that's the way they did it, it was the original Kodak cassette, and these were full 36 frame rolls.  In the literature there is some debate about it. It was recommended to hyper at higher pressure in cassette: 15psi.I have chosen to hyper on reels since I never use much at any one time and usually split up a 36 frame roll to do so. It's noted to loosen up the tension in film roll. What's often recommended is to skip frames so humid air has less of a chance to affect the adjacent frame. Estimate how many frames will be lost as a leader when loading the camera; That's about 4 or 5. An 18" strip of film is a bit too little yielding about 8 or 9 consecutive frames. Since mistakes are common, I would just split a 36 frame roll into two giving some extra redundancy, yielding about 2.25ft each. That will yield around 15 consecutive frames; enough to skip every other frame for around eight separate shots. If it was a 24 frame roll I wouldn't split it, but you of course have a bulk roll. 

 

What you might want to do when you have nailed down the proper hypering procedure is hyper a few cassettes of however many frames you want and store them in the freezer and test them over the next several months to a year. You can hyper a bunch at one time and have them stored for year round use. After hypering the film and it's cooled down, it can be store in its film cannister with a few desiccating beads to scavenge for moisture and seal the lid with electrical tape, put it in a couple freezer bags or airtight tupperware container and store in fridge.

Edited by Todd N, 06 March 2023 - 12:45 AM.

[TxStars]

I always liked short rolls but preferred cut film or plates when doing comet and supernova searches b/c I would develop them right after shooting.

With the humidity in my area any hypered film not stored in nitrogen or another desiccant begins loosing ground by the next night, so I would opt for fresh.

Spending an hour and more manually guiding a single image reduces your acceptance for things that are not 100%  ..lol

Edited by TxStars, 06 March 2023 - 05:14 AM.

[Michael Covington]

What I have never been able to find out is why forming gas is called forming gas.  I understand it existed before gas hypering was discovered, and was used for some processes that required an oxygen-free atmosphere (some kind of metal processing and semiconductor manufacturing, I think).  Why "forming"? What is the rest of the story?

[xonefs]

Thanks all.

I got the hypering kit. Looks like the pressure gauge on the chamber is a bit bent I may need to get a new one. I’m a bit confused on the different connections on the hose splitter and proper way to set it up I’ll have to read. It came with original lumicon paperwork and I also have a few used astro books coming that were recommended.

For the nitrogen supply- does it make sense to just order a smaller tank of calibration nitrogen I saw mentioned previously? Not sure how much gas is needed. It’s that or deal with trying to get a 20cf cylinder locally which may be much. In either case I will probably just inject a bit of nitrogen while shooting as I was thinking anyway.

I got sent a tank of original forming gas. Tank shows maybe 150psi- how much is left of that and that good for hypering?

Also my tech pan is a 150ft bulk roll- so I will have to manually load cassettes anyway. I guess I could hyper as much fits on a reel then load into a few cassettes and store. Just seems like it might be a bit tricky loading from the reel.

Edited by xonefs, 06 March 2023 - 11:56 AM.

[TxStars]

@ MC

Forming gas is great for making and working with metals as it is endothermic.

The reaction between a metal and the hydrogen removes oxidation from the metal and produces water.

The nitrogen acts as a desiccant and removes moisture thus helping to produce a very pure product.

 

I was told it was b/c H2N2 in their various % are "formed" from the reaction that generates it.. I have never seen this written in any text or publication.

 

 

btw when is the next book coming out ?  lol

Edited by TxStars, 07 March 2023 - 02:13 AM.

[SMigol]

These notes are great and I plan to use them for reference when I eventually build a 4x5 tank.

 

My local welding/gas supply has containers of 95/5 nitrogen/hydrogen forming gas readily available.

 

I have read that the vacuum chambers with forming gas are also used to dry wood.

[Todd N]

Thanks all.

I got the hypering kit. Looks like the pressure gauge on the chamber is a bit bent I may need to get a new one. I’m a bit confused on the different connections on the hose splitter and proper way to set it up I’ll have to read. It came with original lumicon paperwork and I also have a few used astro books coming that were recommended.

For the nitrogen supply- does it make sense to just order a smaller tank of calibration nitrogen I saw mentioned previously? Not sure how much gas is needed. It’s that or deal with trying to get a 20cf cylinder locally which may be much. In either case I will probably just inject a bit of nitrogen while shooting as I was thinking anyway.

I got sent a tank of original forming gas. Tank shows maybe 150psi- how much is left of that and that good for hypering?

Also my tech pan is a 150ft bulk roll- so I will have to manually load cassettes anyway. I guess I could hyper as much fits on a reel then load into a few cassettes and store. Just seems like it might be a bit tricky loading from the reel.

 

It does make sense to buy a larger volume cannister of N2 since you will use more of that in the purging and temporary storing of hypered film. I buy from Mesa gas and they have larger tank sizes. When I first started out bought the smaller 34L tanks and each size has a different regulator which are quite expensive. After I figured out a larger N2 tank would have been better, it wasn't cost effective to upgrade. I would suggest 3x the volume of N2 to H2. You should repeatedly purge your tank(2-3X) along with vacuum pumps to near eliminate residual O2 and water in the chamber before adding H2.

 

If that gas is any good, you will never know until you try.

 

I use plastic reels which are self feeding... no problem.  Metal reels are notoriously difficult to load film. Turn the reel until the end of the film passes the feeder that the film inserts to, whatever one calls that. You can pull the film out with no problem. So, you tape the spool to the end of the film and you can slowly release the film as you wind it along the spool, then apply the cannister body and cap. Electrical tape works well to secure film to spool. This may be a little tricky getting the hang of it doing this in total darkness. I would practice with a dummy roll. The most common mistake is to tape the spool upside down. 

Edited by Todd N, 06 March 2023 - 05:14 PM.

[aspy2000]

Great thread! What about hypering 120 medium format film? Can I put the 120 format TP2415 I have directly into the tank and put some pressure (14 psi?) like 35mm in cassettes or do I absolutely need to unroll the unexposed film onto a reel?

Thanks

[Todd N]

Great thread! What about hypering 120 medium format film? Can I put the 120 format TP2415 I have directly into the tank and put some pressure (14 psi?) like 35mm in cassettes or do I absolutely need to unroll the unexposed film onto a reel?

Thanks

 

Use something like 3psi which is a common stated figure for hypering films. 14psi is too high. You could play around with it a bit, anywhere from 1 to 5psi is probably fine but you want to standardize for consistent results. I recall the paper backing in 120 presents a problem and has to be removed and desiccated before being placed back on the film or the moisture could fog the film. Plus, 120 film is rolled tightly as can be and won't allow even hypering so, it need to be on a reel, IIRC. There is a fair amount of space in a 35mm cassette and even then I have read it is recommended to loosen up the tension. 

[aspy2000]

Thanks Todd. One question for you. I have the hardest time to find forming gas here in New Mexico. I'm looking at weeks for turn-around and surprisingly, no-one at those gas suppliers heard of a 8% H2 concentration w/ 92% nitrogen mix.

 

I could order from Mesa Gas you mentioned in other threads. But I can't find the exact ref when looking through their website. I would need a simple 34L cylinder with I guess a standard Pressure Regulator. What would you recommend?

[Todd N]

Thanks Todd. One question for you. I have the hardest time to find forming gas here in New Mexico. I'm looking at weeks for turn-around and surprisingly, no-one at those gas suppliers heard of a 8% H2 concentration w/ 92% nitrogen mix.

 

I could order from Mesa Gas you mentioned in other threads. But I can't find the exact ref when looking through their website. I would need a simple 34L cylinder with I guess a standard Pressure Regulator. What would you recommend?

 

A forming gas mix is not a standard product. Contact Mesa directly. They offer custom gas mixtures:

 https://mesagas.com/...n-gas-mixtures/

 

I chose their basic Series 400 valve for a 34L tank: https://mesagas.com/...flow-regulator/

But it has various flow options. I choose the lowest .25 LPM flow rate. It actually takes N2 a couple of minutes to fill a tank up to pressure. A slightly faster valve flow rate would be OK also. 

 

Even with a forming gas mix I would recommend getting a couple of cannisters of N2 and another regulator or a larger one for the purges. No point in wasting the forming gas in doing purges.