Film hardener?

[AgentX]

Look in an automotive supply store.

 

[michaelbsc]

If you wish to harden very soft films, use a prehardener as follows:

Sodium SulfATE 50 - 100 g/l
Formalin 37% 10 ml/l
Sodium Carbonate 25 - 50 g/l

pH range 9 - 10

Use 5 mins at 20 deg C, wash 5 mins and then process normally.

PE

This is a single use and discard? How long will it keep if I mix up several liters?

 

[john_s]

I use a squeegee with mainstream films (Kodak, Fuji, Ilford) and have never had a scratch that I could detect. I'm fastidious about keeping it clean, and I rinse it in running hot water (50degC) before using it. I think that the heat causes the rubber to become softer.

 

[2F/2F]

I find that Photo Wipes work well also (green lint-free paper towels that you can get at any photo store that stocks analog supplies).

 

[hrst]

and I have never seen distilled water here (which is what I used while living in Canada and France), although I'll be the first to admit it may be available somewhere in this country, just not in the places that I've looked (supermarkets, drug stores, hardware stores).

Look for "battery water". I think there might be some cars in Japan, and unless they always throw in a new battery and discard the old one when it just needs some water, there should be battery water available . It's usually not steam distilled but demineralized. I would guess even gas stations would carry it also there...

 

[mooseontheloose]

Thanks -- I'll try to check it out the next time I go shopping.

 

[nworth]

How are the scratches happening. If it is in the camera, the camera needs to be cleaned or repaired. If it is in loading the film into the tank, you need to be more careful. If it is during or after processing, the hardener may help. Most such hardeners are added to the fixer and help to protect the film after processing.

 

[Ian Grant]

With a one shot developer you can add a few drops of Formaldehyde to the developer itself, 4 or 5 are usually sufficient per film. That's what I used to use with the older unhardened Adox/Efke films, these days they do have some hardener and are a bit more robust.

The interesting thing about tanning developers is that they only tan the image areas. Unless the fog is extraordinarily high, there is no tanning in Dmin areas. Thus, scratches can take place in clear areas and turn up as artifacts in the final print.

PE

That's not a fault of tanning developers though, the same happens in a non tanning developer

In general a tanning developer seems to help overall, but the bigger problems come from developers with Na or KOH in them with poorly hardened emulsions and there have been many reports of issues with Acros particularly with Rodinal.

Ian

 

[RobertV]

I'll try to check it out the next time I go shopping.

You could try a Brita (TM) filter too:

http://www.brita.net/uk/?&L=1

At the end much cheaper for making good water. I am paying Eur. 2,00 for 5 ltr. destilled (demi- ) water. A Brita filter costs Eur. 4,00 and is able to make 100 Ltrs. Apart from the fact your (photo ) water is always direct available.

 

[ZorkiKat]

The prehardener which Ron PE posted also works great. I used something similar for developing "Negra" film (Spanish made, long extinct? was "Lumipan" in the USA) in the past. It had a very soft emulsion which had the tendency to swell in warm water. The formaldehyde hardens the film, and the sulfate reduces the swelling.

The prehardener, AFAIK can be reused several times, or at least until it goes murky.

As for adding alum-based hardener to fixers, the lack of sodium sulphite will guarantee the precipitation of sulphur from the solution. This makes the fixer very cloudy and will eventually become useless. A small amount of sulphite (15 grams/litre) will prevent this from happening. When the solution is warm, there is a tendency for light clouding to happen, but this will usually clear in time.

Another hardening stop bath can be made from Potassium Chrome Alum. A 50 gram/litre solution should work. However, the green brew that results can only be used once or in quick succession since it can go bad quickly (? not really sure...._)

 

[Leigh Youdale]

Hanging Offence

I use the wet finger method (no ribald remarks please) and sometimes one other thing that Roger Hicks suggested. Pin the film more or less diagonally across a doorway so any water runs to the lower edge of the film and not directly straight down the length of the film strip as it does when the film is suspended vertically.
Makes sense - works for me. Just find a doorway that nobody is using!

 

[Ian Grant]

I use the wet finger method (no ribald remarks please) and sometimes one other thing that Roger Hicks suggested. Pin the film more or less diagonally across a doorway so any water runs to the lower edge of the film and not directly straight down the length of the film strip as it does when the film is suspended vertically.
Makes sense - works for me. Just find a doorway that nobody is using!

I've used the same technique for 40 years, (not the diagonal bit) always works perfectly even with Foma and Acros. With 35mm Iuse a piece of kitchen towelling to remove all water fom the back saves drying marks.

Ian

 

[Photo Engineer]

NaOH and KOH developers generally cause a lot of swell for 2 reasons. One is the lower salt content used to reach a given pH which allows greater swell. Salts tend to reduce swell. The other reason is that Hydroxide based developers have a higher pH and thus tend to cause more swell of bone gelatin based films. If films were made of pig gelatin, then swell might be lower at a more alkaline pH!

There are illustrations that show that normal "hardening" developers or "tanning" developers can cause image distortion at the 1 micron to 10 micron level. This is no problem with LF or Dye Transfer systems, but can be seen in small objects in 35mm. So I suggest tests and caution.

PE

 

[Robert Budding]

Robert;

There apparently are some soft films out there from some companies. That alone would suggest that one use a hardener in some way in the process.

That said, what if the soft film scratches in the developer? A hardening fix is of no use. And, bone gelatin swells most in alkali and is therefore softest! So, a prehardener makes sense in some conditions.

PE

That makes sense for tray development. Once I've placed film on a spool, however, there's little chance of scratching it prior to the fix.

Anyone here have experience with Kodak's hardening fix?

 

[ZorkiKat]

That makes sense for tray development. Once I've placed film on a spool, however, there's little chance of scratching it prior to the fix.

Anyone here have experience with Kodak's hardening fix?

It's the only fixer I use. All the older books refer to it as the fixer to use for film. Hardening is the operative word, to protect the film against swelling, frilling, separation from the base, reticulation, etc. Started using it when I started film developing 25 years ago. Tried the other non-hardening brews, but never liked them. Tropical climates and warmer wash waters don't make its use with most films appealing.

It's not just scratching from physical abrasion that's to worry about. Swollen gelatin can swell or frill or reticulate, even if the film was not handled and stayed in the rack or reel.

 

[ZorkiKat]

Another thing about hardening: by all indications, it would make sense to think that hardened emulsions in a finished negative should have better keeping qualities than an unhardened one. Humidity can still make the gelatins swell after processing. Formalin/Carbonate hardeners were supposed to preserve the negative better. The formaldehyde component acted as a biocidal agent to keep the gelatin-eating germs away.

PE, may you please comment on this?

 

[Photo Engineer]

Silver in B&W films help preserve the gelatin from bacterial and fungal growth. Formalin can only make it better, I suppose, but the regular hardeners in good films can also do that by blocking the "edible" amino acids in gelatin just like formalin.

Alum based hardeners can be reversed sometimes and allow film to lose hardness during keeping. Chrome based hardeners are better than Alum based, but are more toxic and less stable in solution.

That is a thumbnail sketch of a huge subject and is just a bit of generalization as well. So, I may have to write a new book on that too. OMG! A book on Developers, Stops, Fixers and Washing like Anchell and Troop only longer. I'd better call Bill ASAP!

PE

 

[Robert Budding]

I think I'll start using Kodak's hardening fix. Seems that there are some excellent reasons to use it. Any downside, other than longer wash times?

 

[Photo Engineer]

I think I'll start using Kodak's hardening fix. Seems that there are some excellent reasons to use it. Any downside, other than longer wash times?

It does not keep as well as some neutral and alkaline fixes, if you add the Alum hardener.

PE

 

[Ian Grant]

It does not keep as well as some neutral and alkaline fixes, if you add the Alum hardener.

PE

Or normal slightly acidic fixers like Hypam, or Ilford and Kodak Rapid Fixers - pH 5.2-5.4

Ian

 

[Robert Budding]

How less-well does it keep?

 

[Photo Engineer]

I have kept pH 6 - pH 9 fixers for several years at working strength, but I have rarely been able to keep KRLF with hardener for more than 1 year at working strength. It was at pH 4.5. I have some fixer tests going at 5+ years for the concentrate and 2+ years for the working strength. I have one in a tray that evaporated and I redissolved it and kept using it though 3 cycles and lasted about 6 months in an open tray this way. This was pH 6.5, roughly the mean of my tests.

Does this help?

PE

 

[2F/2F]

Speaking of gelatin, I just found out from a vegan that they theoretically do not practice analog photography, due to the use of gelatin. That was a new one for me!

 

[Sirius Glass]

Speaking of gelatin, I just found out from a vegan that they theoretically do not practice analog photography, due to the use of gelatin. That was a new one for me!

One can understand the logic. If a vegan really got into photography, the vegan would be acussed of sinking their teeth into the medium.

 

[Ian Grant]

There are illustrations that show that normal "hardening" developers or "tanning" developers can cause image distortion at the 1 micron to 10 micron level. This is no problem with LF or Dye Transfer systems, but can be seen in small objects in 35mm. So I suggest tests and caution.

PE

While there's undoubtedly truth behind that with older Pyrogallol etc tanning/staining developers they were used quite differently to the modern highly dilute developers like nPyrocat and PMK, and weren't suitable for miniature films 120 or 35mm etc. They were often designed to maximise these effects particularly for contact printing.

Non tanning/staining developers can cause similar problems of exaggerated edge effects with smaller negatives which is why some commercial high acutance developers of the 60's annd 70's never became successful and were withdrawn.

Ian