Model 14 Photo Booth - chemicals question

Hi there, friendly photo forum folks! I am hoping that this is the correct place to post this question -- if not, I'd appreciate redirection to wherever that may be!

My husband purchased a Model 14 photobooth ~10 years ago as his engagement gift to me, and we (mostly he) managed to keep it in pretty good working order up until this past year when our previous supplier for chemicals and paper fell out of contact. We have a second photo booth that used to be in his bookstore and we'd like to get it back in working order in the next year as well, but figured we ought to get ours at home up to snuff first.

We managed to get a roll FOMA photobooth paper and have been following this guide for the chemicals -- https://www.freestylephoto.com/static/pdf/product_pdf/foma/FOMA_PAPER_PHOTO_BOOTH_SETUP.pdf -- but the photos are not reversing/developing correctly. I figured that someone on these forums would likely have an idea of what's going wrong, or at least might have an idea where to point me! This was the first time we tried ordering chemicals individually instead of getting them in a photobooth kit, so there is every chance we got one or more of them wrong.

The chemicals we're using:

Clayton P20 Plus Developer
Moersch Bleach
LegacyPro Clearing Agent
Ilford Selenium Toner


Here is a photo of how the strips are currently turning out:



Thanks to all of you in advance for any advice or suggestions you can provide -- I am happy to provide additional information or photos if that will help.

The problem is the bleach. You probably need a non-rehalogenating bleach, like potassium permanagate or dichromate.
If use permanganate then you need metabisulfite clearing, if you choose dichromate you need sulfite clearing.
Toner: a thiourea based one.

I don't know where you were getting suspplies, But Photosys.com, the same folks who now make the Kodak Chemicals also apparently still make Photo Booth chemicals. You might find that trying their bleach may help you figure out your problem.

I had no idea this was still a thing. Cool.
And welcome, someone here will know what to do.

storyofohno said:

Here is a photo of how the strips are currently turning out:

Click to expand...

As @Alessandro Serrao mentions above, your problem is the bleach.

The bleach you purchased is a generic potassium ferricyanide bleach that's used e.g. in B&W print processing to selectively lighten areas on a print, or as a bleach step prior to the use of certain toners. It does not work in your application.

The Foma paper you've purchased is a regular negative-working printing paper. This means that when the paper is exposed to light and then developed, the image formed will be a negative image. Bright areas in the actual scene will become dark areas on the paper, and vice versa. In your photobooth application, the paper needs to be 'reversal processed', which means that it goes through the following steps:
1: Exposure of the paper to the scene, with flash
2: Development of the negative image in a suitable developer
3: Destruction of the negative image through (non-rehalogenating) bleach. This requires a specific 'reversal bleach' which is generally an acidified solution of potassium permanganate.
4: Re-development of the remaining silver halide that did not make up the negative image - this happens to be the positive image that you do want.

The re-development step can be done in either of two ways:
1: Re-exposure of the paper to light or a chemical fogging agent. This turns the remaining unprocessed silver salts into developable silver salts. Then, the paper is developed again in an ordinary developer just like the one used for the first development step.
2: The remaining silver salts are chemically bound to a toning agent that turns them into a dark material; in the PDF you used as a guide, a sepia toner is used that binds the silver to sulfur, creating brown silver sulfide.
Option #2 is somewhat simpler because it doesn't require an additional fogging step (light or chemical). Its drawback is that you end up with a brown/sepia image. If you want a neutral greyscale image, you need to use option #1, but this may require heavy modification to the photobooth process.

As to the bleach options: @Alessandro Serrao mentioned either potassium permanganate or (potassium or ammonium) dichromate as the basis for the bleach. I'd recommend sticking with the former. Dichromate is based on hexavalent chromium; in the EU, its sale and use are effectively banned due to severe health and environmental concerns. In the US, it can still be purchased, but it should really only be used (1) if there's no viable alternative and (2) by people who thoroughly understand the risks associated with its use and who are equipped to handle and dispose of the material safely. Sensible use of dichromate is not necessarily exceedingly dangerous or harmful, but if you're new to photochemistry, it's not the place I'd recommend to start. Permanganate is also nasty stuff, but not half as bad as dichromate.

cmacd123 said:

I don't know where you were getting suspplies, But Photosys.com, the same folks who now make the Kodak Chemicals also apparently still make Photo Booth chemicals. You might find that trying their bleach may help you figure out your problem.

Photo Booth

www.photosys.com

Click to expand...

This is promising, but I'd recommend contacting Photosys and inquire with them whether these chemicals can be used in your particular photobooth system, and what the instructions for use are.