Acid or Caustic to Clean Plastic JOBO Equipment?

[Jay Decker]

Acquired all the bits to process film with a JOBO CPP-2 processor. Some of the drums have some chemical residue on them. Is acid, caustic, or something else the best to clean JOBO plastic?

[Jon Wilson]

I have always used water and a sponge. Presumably, the residue is from photo chemicals which were not cleaned out, the residue was just allowed to dry. I would recommend maybe hot water and a sponge. Repeat as needed. IMO any clean solution might leave a residue which could adversely affect future developing endeavors.

Jon

[Jim Michael]

We used bathroom cleaner containing phosphoric acid to clean processing equipment used for color processes and it was effective in removing tar and other built-up chemicals. I think the residue you have is going to depend on the type of processing that was done. Do you know what the equipment was used for (E-6, C-41, B&W, etc.)?

[RPNugent]

Here's what Greg Blank from Omega Satter said in a thread on maintaining JOBO's.

Jobo does not recommend using bleach in the plastic tub, maybe because people don't tend mix bleach intelligently? Process clean is the preferred stuff that Omega Satter distributes for cleaning processors it designed to work overnight.

But you could use a soft scrub compound a soft sponge and enough water to lubricate, I use a small soft brush to clean everything it is a little faster. Windex will remove the caked on fixer sulfer.

[W K Longcor]

We use to use a bathroom bowl cleaner called "sani-flush" --- don't know if it is still around or not. Does a super job of cleaning, especially on "tar" residue -- rinses away easily , and leaves your darkroom " fresh smelling!"

[Sevo]

Jobo used to sell a processor and tank cleaner which was nothing but crystalline amidosulfonic acid.

[Jay Decker]

Have no idea what the brown gunk is on one of the drums... it kind of looks like the dried residue in a spittoon.

Didn't think of Sulfamic (amidosulfonic acid), but that would be a good choice. I was thinking of trying vinegar (weak acetic acid) or lye (sodium hydroxide). Any experience with vinegar or lye, or any other suggestions?

[Dave Grenet]

Just FYI, I believe sulfamic acid is often available as 'descaler' for coffee machines and kettles.

[Kirk Keyes]

I used Soft Scrub on my old CPE-2 when I sold it. It looked like new when I was done cleaning the dried0-on chemicals off it.

[Jim Galli]

Jay,

I'm sure you'll figure it out and share your experience with the rest of us. When clean though, I have a recommendation to keep them sparkly. Buy a bit of sodium hexametaphosphate on Ebay (a lifetime supply is a few dollars) and in your final water wash, add a pinch and let it go through the 2 minute wash (or whatever your discipline is). Save that last wash when you drain and put it in a tray with a drop of Kodak Photo-Flo. Then as you retrieve the films from the Jobo, give them a swish for 20 or 30 seconds in the water + sodium hexametaphosphate + Foto-Flo and not only will the JOBO stay pretty inside, your drip dry will never have any water spots.

To re-cap, I don't let the photo-flo go through the Jobo, but I do let the final wash have some sodium hexametaphosphate, then combine the 2 in a tray. I used to get calcium build up in the JOBO until I started this routine. Desert water is always a bit hard. Good luck and tell us what worked on the brown crud. (sounds like well oxidized dried developer)