Soft emulsion from permanganate B&W reversal

[studiocarter]

It worked. Wish I knew the amounts to mix my own

 

[Gerald C Koch]

It worked. Wish I knew the amounts to mix my own

Just follow Ilford's recipe.

 

[studiocarter]

Would someone please post a link to the bleach information? Thank you

 

[iandvaag]

I'm pretty sure the document is not currently available on their site. Harman Tech has posted here that they are reviewing this document before posting it to their revamped site.

Bleach
Solution A: Add 2 g KMnO4 to 500 mL water
Solution B: 10 mL conc. H2SO4 to 490 mL water
Mix equal parts A and B before use. Only suitable for single use.

I will add that MnO4- is very easily reduced at these low pH (see Pourbaix diagram if you are interested), so I would recommend distilled water.

 

[studiocarter]

When in doubt, read the instructions.
Thank you.
I found a book on my shelf. How To Reverse Movie Film, 1944. Permanganate is one of the two bleaches given as a standard. No mention of emulsion lifting off is given, although, temperature changes are to be avoided in general. Temperature is 65 ( not 68 like current instructions ). Hardener is after bleaching, not before. P. 15: The Permanganate Formula, Water ( not necessarily warm ), [for mixing I suppose], 1 Quart, Potassium Permanganate 45 grains, Sulphuric Acid C. P. 160 minims. Clearing Bath. Water 35 ounces. Sodium Bisulphite 1 ounce. Four minuets is usually sufficient, or longer. A few minuets in the clearing bath. P. 16: "After the second development some kind of a hardening bath should be used when the bleaching was carried out with the permanganate formula".

 

[Photo Engineer]

Do you dance in your clearing bath?

If the emulsion lifts off while bleaching, then a hardener after the bleach will not help.

PE

 

[studiocarter]

You are right.
I wonder if slowly lowering the temperature to say 50 degrees and then bleaching would work then slowly raising the temp back to 65. All that time in water would probably kill it.