Reconditioning old / fogged paper

liza said:

.>
>Are there any APUGGERS that tried following treatment:
Not me, but the thought is intriguing

>Paper are soaked 2-5 minutes (depending on coating) in a mixture of
25 gram potatissumbichromate, 15 gram potatissumbromide and 500 ml water. Glossy papers often need more time.
Papers are very well washed and dried in darkness. OR
To enhance senibility and clarity - papers can after first treatment and wash be put directly into following bath for a couple of minutes: Water 100 ml, potatissumbromide 20 gram and Ammonium 40-50 ml. Rinse again and dry in darkness.

The recipe aboive is akin to an intensifier - the bi/di chromate, with the bromide as the restrianer, or likely in this case here to form silver bromide??

>There is one more recepie but with a chemical "parafenylendiamin". Today hard to get with the special chemical structure as mentioned in the book.

In English I know this as paraphenyldiamine (base) - my short hand calls this PPD. The base developing agent that almost all color developing agent salts are built around.

I have bought PPD from Claire at JD Photochem. I use it in Harveys777/Sease/Edwal ffilm development formulas that also include Glycin. I replenssh them, and they last, and last and last.

PPD is known/highly suspect to be a carcinogen, so if you start to play with it, make sure to get into a nitrile glove wearing darkroom worker, and read up on the MSDS information.

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liza said:

I came across an old recepie in a book from 1950ies that are supposed to remove fog from photopaper without any bleaching and still keep original speed and contrast in the paper. If it works I think it would be very valuable knowledge since paper are getting more and more expencive and less in quality.

Are there any APUGGERS that tried following treatment:

Paper are soaked 2-5 minutes (depending on coating) in a mixture of
25 gram potatissumbichromate, 15 gram potatissumbromide and 500 ml water. Glossy papers often need more time.
Papers are very well washed and dried in darkness. OR
To enhance senibility and clarity - papers can after first treatment and wash be put directly into following bath for a couple of minutes: Water 100 ml, potatissumbromide 20 gram and Ammonium 40-50 ml. Rinse again and dry in darkness.

Basicly it should work but since there is less silver in todays papers I guess some adjustments have to be done.

There is one more recepie but with a chemical "parafenylendiamin". Today hard to get with the special chemical structure as mentioned in the book.

Another treatment mentioned is the Herscheleffect with exposing the papers under infrared filters and strong lightsourse. Anyone tried this?

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Thomas Bertilsson said:

That's really cool. There is also an old Defender formula called 58-D, that Randy Libersky has been promoting. It contains chlorohydroquinone, however, which is difficult to get.
Basically, I've seen his prints made on old paper, from the 1920s to the 1950s, and it's practically fog free. I tried it on some paper that was hopelessly fogged in regular chemistry, and it worked great.

Just another option. The formula for it should be in the APUG recipe section.

- Thomas

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