Hypo clear?

[MichaelGJ47]

G,Day all
I am just getting back in to film photography and setting up a darkroom.Years ago when I taught darkroom courses we all use hypo clear after fixing and I notice now it seems to have gone out of use .Can someone bring me up to date on to use it or not.
Thanks
Michael

[Eric Woodbury]

Hypo clear, or sodium sulfite, is still used to decrease wash time post fix, especially with fiber based papers. See the directions with your paper of choice.

[LabRat]

Nothing beats a good, full wash, but with hypo based fixers it can save a little time... Rapid fixers don't really need it...

A downside can be a slight haze over low key prints under some conditions like warm water summer washes etc when there is greater swelling of the print emulsion where it leaves a trace over image...

But not needed when a full, good wash is available...

I think it's 40gm/liter of sodium sulfite which is almost identical to Kodak HCA... Other peroxide based baths can also be made up, but a good wash does it too...

Steve K

[Oren Grad]

Assuming a non-hardening rapid fixer: yes for FB prints, no for RC prints or for film.

[Duolab123]

I use Kodak Hypo Clearing Agent routinely after Kodak Rapid Fixer when developing Tmax and similar films to help to remove the last bit of the purple dye used in these and similar films.
For fiber base paper it's part of my routine.

Ilford has great website based instructions on how to use their materials. Fixer protocol has changed dramatically from the "old days"

Ilford has just introduced a new 5th generation multigrade RC paper. If it's been a while you may want to go directly to the source Ilford Photo, look at the instructions. RC paper is quite good today, so easy and fast. And you don't need to fool with hypo clearing agent with RC.

[Doremus Scudder]

G,Day all
I am just getting back in to film photography and setting up a darkroom.Years ago when I taught darkroom courses we all used hypo clear before fixing and I notice now it seems to have gone out of use .Can someone bring me up to date on to use it or not.
Thanks
Michael

A wash aid like Hypo Clearing Agent (Kodak) or Wash Aid (Ilford) is used after fixing and before the final wash. Using it for film helps reduce wash time, but is not really necessary. With staining developers, a wash aid can remove the stain, so don't use it with those.

RC papers don't really need the wash-aid either, since no fixer gets into the paper base.

For fiber-base prints, however, a wash aid is really helpful, not only for reducing wash times, but for ensuring a thorough removal of fixer traces.

Kodak Hypo Clearing Agent comes in powder form. You mix a stock solution, which is further diluted for use. Some have problems using the entire batch before it goes bad due to age.

Ilford's Wash Aid comes in a liquid concentrate which is diluted before use. You mix it as you need it.

If you want to mix your own wash aid, and your tap water is not too hard or full of dissolved minerals, you can just use sodium sulfite and bisulfite (the active ingredients in both the Kodak and Ilford products). I mix mine with simple spoon measurements (precision isn't so critical here): 1 Tbsp sodium sulfite and a pinch of sodium bisulfite (or metabisulfite) per liter.

There are lots of threads on how to use wash aids here and over on Photrio. Kodak's older regime is different than Ilford's processing sequence for optimum permanence.

Hope this helps,

Doremus

[paulbarden]

Years ago when I taught darkroom courses we all use hypo clear befor fixing ...

I do hope you didn't actually mean you were using hypo clear BEFORE fixing, as that would be pretty pointless.

[MichaelGJ47]

yes I meant after fix before wash

[Roberto Nania]

Hello to all,

I use Photographer's Formulary hypo clear for helping washing my film.
I noted that even after few runs (so, before being exhausted) it develops some white ropey residuals floating.
Is that a sign of exhaustion or not really? Should I filter the solution or discard it and make a fresh one?

Sometimes I used Kodak Hypoclearing (which is way more expensive) and I haven't seen any residual.

Thank you for your answers

[Doremus Scudder]

Hello to all,

I use Photographer's Formulary hypo clear for helping washing my film.
I noted that even after few runs (so, before being exhausted) it develops some white ropey residuals floating.
Is that a sign of exhaustion or not really? Should I filter the solution or discard it and make a fresh one?

Sometimes I used Kodak Hypoclearing (which is way more expensive) and I haven't seen any residual.

Thank you for your answers

Even Kodak Hypo Clearing Agent in working dilution will develop bacterial/fungal "slime" after a time. The best practice is to mix what you need for one batch/session and discard it after the session is over. Storing the working solution even for a few days in the right conditions will grow slime.

The same applies to citric-acid stop baths.

Best,

Doremus

[Kirk Gittings]

You can simply use Sodium Sulfite as a one shot wash aid-a heaping teaspoon per quart of water.

[Drew Wiley]

I use TF4 archival fixer instead. More expensive, but saves a lot of time and fuss. No need for a wash aid.

[Roberto Nania]

Thank you all, gents

[Hans Berkhout]

Kirk plse clarify: one teaspoonful or one tablespoonful per quart of water? I think you meant to write tablespoonful.

[Roberto Nania]

I ordered one kilo of Sodium Sulfite for one shot use.
I think it's a teaspoon (around 20gr) for one liter of water for film use, isn't it?

[LabRat]

I remember it as 40gm/1 ltr...

Steve K

[Doremus Scudder]

I remember it as 40gm/1 ltr...

Steve K

Most of the formulas I've collected weigh in at about 20g sodium sulfite per liter of working solution wash aid.

My spoon recipe calls for one level Tablespoon of sulfite per liter, which weighs in at 22.8g give or take. I add a pinch of bisulfite/metabisulfite too.

For those with hard water, other ingredients might be needed: EDTA Terasodium Salt or sodium hexametaphosphate for hardness and citric acid to adjust pH/buffer.

Kirk's "heaping teaspoon," depending on how "heaping" it is, may come close to 20g/l...

Best,

Doremus

[Willie]

I use Kodak Hypo Clearing Agent routinely after Kodak Rapid Fixer when developing Tmax and similar films to help to remove the last bit of the purple dye used in these and similar films.
For fiber base paper it's part of my routine.

Ilford has great website based instructions on how to use their materials. Fixer protocol has changed dramatically from the "old days"

Ilford has just introduced a new 5th generation multigrade RC paper. If it's been a while you may want to go directly to the source Ilford Photo, look at the instructions. RC paper is quite good today, so easy and fast. And you don't need to fool with hypo clearing agent with RC.

Having listened to many Older Photographers who are excellent printers I wonder if anyone doing "fine work" is using RC Papers? I know Clyde Butcher got bit from using them years ago and a number of others who were using them had to change. Labs that were printing with the papers went under rather than have to reprint many of the images that started developing problems.

Does anyone know of a major "fine work" printer who uses RC papers today?

[neil poulsen]

How does Perma Wash compare to Kodak HCA? Is it basically the same stuff?

One nice thing about Perma Wash, is that it's a liquid concentrate. So, it's easy to mix as needed.

What's the shelf life of HCA Stock Solution, mixed directly from the package before diluting it with water for a working solution?

[Doremus Scudder]

How does Perma Wash compare to Kodak HCA? Is it basically the same stuff?

One nice thing about Perma Wash, is that it's a liquid concentrate. So, it's easy to mix as needed.

What's the shelf life of HCA Stock Solution, mixed directly from the package before diluting it with water for a working solution?

Neil,

According to the label on Kodak's Hypo Clearing Agent, the stock solution lasts three months in a tightly-stoppered bottle (working solution life is 24 hours in a tray).

As for Perma Wash... I've always been a bit skeptical, but have never tested it. According to a scan of the label I have, it contains ammonium sulfite and sodium sulfite. The MDSD only lists the ingredients as "trade secret" and has such warnings as "use only outdoors or in a well-ventilated area." However, it does give the amount of dissolved chemicals as 33.886%.

So, let's do a little math. Instructions say to mix 3 oz. of Perma Wash with a gallon of water. Assuming a v/v percentage in the MSDS, that makes 1.01658 oz. of "active ingredient" per gallon. Converting to g/L we get approx. 7.6133 grams of whatever mix of ammonium and sodium sulfite is in Perma Wash per liter of working solution.

That's nowhere near Kodak's 20 (or a bit more) g/L of sodium sulfite. Unless ammonium sulfite is much, much more efficient than just plain sodium sulfite, the solution seems pretty weak to me. If I were to have to use Perma Wash, I'd certainly do a residual hypo test to find the limits of washing just to be sure. I've done that with my sodium-sulfite-based wash aid.

Best,

Doremus

[reddesert]

Here is an MSDS for Perma Wash that lists a couple of ingredients: https://art.illinois.edu/images/documents/MSDS/Darkroom-SDS/Heico-Permawash.pdf
Ammonium sulfite and sodium ethylhexyl sulfate are the two listed.

Ammonium sulfite is close to the same sulfite ion per molecular weight as sodium sulfite. I don't know if ammonium sulfite acts faster or more efficiently than sodium sulfite. I washed longer than their (IIRC) somewhat absurdly short recommended wash times. Perma Wash is a little more convenient and/or stock solution is longer lasting than Kodak HCA, but if one is making wash aid from sodium sulfite that's less of an issue.

I have films and RC papers from 20-25 years ago that were wash-aided with Perma Wash and don't seem to have degraded, but no fiber base papers, and I didn't do residual fixer tests.

(By the way, why does ammonium thiosulfate (rapid fixer) fix faster than sodium thiosulfate? I wondered if that was related, but couldn't find an answer, even though it is presumably well understood.)

[alt.kafka]

I put 12.5g of HCA in 500mL of warm water with a magnetic stirrer at the start of each session. It's kind of hard, so the heat and the stirrer help it to be completely dissolved by the time I need it.