How to clean darkroom materials after use?

fschifano · Sep 17, 2009

You're right, of course. Detergents are there to dissolve oils and fats, none of which are present in photo chemistry. I can see where they might make a bit of a difference if there is an oily film deposited onto the hardware from an airborne source. Soot from an oil or coal fired furnace could do it, and in fact, did in my case. That old and creaky oil burner is long gone though, having been replaced with a much more modern, natural gas fired unit, and with it the problem which affected the entire basement of my house.

dancqu · Sep 18, 2009

bdial said:
I have rarely done anything more than rinse my trays,
reels, tank etc. ......... I have some concern that soaps
or detergents could leave something behind to
cause contamination.

I have a devil's advocate question; What is it that soap or
detergent is supposed to remove that rinsing cannot?

Ditto. Some worry too much. Soap or detergents must
be washed out.

To the question: Dirt, some of which may carry
minute amounts of oils and grease. A much
diluted soap should do. Dan

mohmad khatab · Jan 5, 2020

Recipe for cleaning tools for dark room rollers.
I am in trouble ,,
These rollers are completely new and this is their first use.
- The story is ,, I prepared the C41 developer
But instead of using (CD4) I added (CD2) since I was able to get a quarter of a kilo of it for free - so I thought I would add it instead of (CD4), with a commitment to achieve the appropriate amount of course.
- The results of the tests were very impressive and everything was fine - and when I processed several rolls at the same time, I brought the new tank where it is five rollers.
- Leaving sinister oil spots that I could never wash them in all ways and methods.
I made a water solution + 10 ml sulfuric acid + copper sulfate + potassium persulfate.
It didn't help, and the oil stains remained the same.
Regarding films, the results were very impressive and were not affected by these stains at all. I used the great copper bleach (which is the company of AGFA and not the simple copper bleach).
I don’t know what to do with these sinister oil spots.

mshchem · Jan 5, 2020

Potassium dichromate and sulfuric acid, dilute. Recipe is old. Nasty stuff a few grams and a few milliliters of acid in small plastic container, one reel at a time, dilute with water. This stuff needs to be disposed of properly. I have found it can be reused almost indefinitely. I have a dilute 250mL bottle that I have used for a couple years.
If you don't have access to small quantities of the chemicals, I would try something else.

Anon Ymous · Jan 5, 2020

mshchem said:
Potassium dichromate and sulfuric acid, dilute. Recipe is old. Nasty stuff a few grams and a few milliliters of acid in small plastic container, one reel at a time, dilute with water. This stuff needs to be disposed of properly. I have found it can be reused almost indefinitely. I have a dilute 250mL bottle that I have used for a couple years.
If you don't have access to small quantities of the chemicals, I would try something else.

I suspect this is the only thing that may have an effect, but certainly has to be disposed of properly. Sodium sulfite, an excess of, will convert hexavalent chromium to trivalent. In a much lighter case of stained reels, mostly from E6 chemicals, a permanganate - sulfuric acid bleach, followed by a sulfite - metabisulfite bath did absolutely nothing. It may have worked ok if it was silver based stain, but this one wasn't.

mshchem · Jan 5, 2020

If you are getting good results, the stain is not important.

mohmad khatab · Jan 5, 2020

mshchem said:
Potassium dichromate and sulfuric acid, dilute. Recipe is old. Nasty stuff a few grams and a few milliliters of acid in small plastic container, one reel at a time, dilute with water. This stuff needs to be disposed of properly. I have found it can be reused almost indefinitely. I have a dilute 250mL bottle that I have used for a couple years.
If you don't have access to small quantities of the chemicals, I would try something else.

Potassium dichromate
It is not available in Egypt -
Officially, it is a prohibited element by the government.
Unofficially, it is hardly available, but it is very expensive
One gram = one dollar

mohmad khatab · Jan 5, 2020

Anon Ymous said:
I suspect this is the only thing that may have an effect, but certainly has to be disposed of properly. Sodium sulfite, an excess of, will convert hexavalent chromium to trivalent. In a much lighter case of stained reels, mostly from E6 chemicals, a permanganate - sulfuric acid bleach, followed by a sulfite - metabisulfite bath did absolutely nothing. It may have worked ok if it was silver based stain, but this one wasn't.

Yes - this staining is currently not harmful and the rollers can be used without any damage.
- But I want to sell this tank and I cannot because of this staining.

mohmad khatab · Jan 5, 2020

mshchem said:
If you are getting good results, the stain is not important.

Yes - the results were more than impressive
Also, the number of produced rolls was large compared to the traditional Formula containing (CD4).

Yes - this staining is currently not harmful and the rollers can be used without any damage.
- But I want to sell this tank and I cannot because of this staining.

kevs · Jan 5, 2020

Before resorting to dichromate (save it for gum printing!), my first stop would be a household chlorine-based bleach. Test on an inconspicuous area. Dilute thick bleach 1:5 and soak the spirals for 12 or more hours. Caustic soda (Sodium hydroxide) might be worth a try too, though don't mix the two!

mohmad khatab · Jan 5, 2020

kevs said:
Before resorting to dichromate (save it for gum printing!), my first stop would be a household chlorine-based bleach. Test on an inconspicuous area. Dilute thick bleach 1:5 and soak the spirals for 12 or more hours. Caustic soda (Sodium hydroxide) might be worth a try too, though don't mix the two!

Well - it's okay. I'm going to do your advice. - Why not?

Bikerider · Jan 6, 2020

To clean stained developing trays, deep tank processors, developing tanks there is no better cleaner than ordinary household bleach diluted around 1 part to 3 of water. Cheap, effective and doesn't damage the surface. With badly stained deep tank processors the bleach will work …..eventually, but it will take a little time. patience is needed if they are very badly encrusted with tar.

Bikerider · Jan 6, 2020

mohmad khatab said:
Well - it's okay. I'm going to do your advice. - Why not?

DO NOT clean any aluminium articles in Caustic Soda...…... it will dissolve them!

mohmad khatab · Jan 6, 2020

Bikerider said:
DO NOT clean any aluminium articles in Caustic Soda...…... it will dissolve them!

It seems that your advice will come with some success.
- I put some grams of caustic soda and some Ma and closed the tank from evening until morning - the result is a slight improvement in color (but it is noticeable). Improvement rate maybe 20%
- But the inner part of the pulley run needs to return the carrot with the addition of more caustic soda and maybe leave it for 24 hours. After that, I think that the toothbrush will be a necessary choice.

kevs · Jan 6, 2020

Bikerider said:
DO NOT clean any aluminium articles in Caustic Soda...…... it will dissolve them!

Yes, good point; I was under the impression Mohmad's spirals are all-plastic affairs like my Paterson ones (save the ball-bearings). I apologise for giving poor advice here.

How to clean darkroom materials after use?

Attachments

Privacy & Transparency

Privacy & Transparency