Archived posting to the Leica Users Group, 1999/08/17
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 01:15 PM 17/08/99 -0700, you wrote: >Roy Feldman wrote: >> >> I realize there are commercially available products but--- Does anyone have >> a home brew for cleaning plastic developing trays? > >For years I marked my trays. Now I don't. The best thing to clean a developer >tray is fix. Use a concentrated potassium permanganate solution. It is a strong oxidizer. Let it stand in the tray for several hours. You can also add concentrated sulfuric acid to it for greater efficacy. Remove, then repeat using sodium metabisulfite or sodium bisulfite solutions. It chemically acts to take care of the permanganate stain. Works well. I've used it. The permanganate/sulfuric acid mixtures are common reversal bleaches. Another home brew cleaner can be made using a mixture of sodium dichromate, sodium sulfate, sulfuric acid and sulfamic acid, if you happen to have the chemicals available. These are essentially the ingredients used in Edwal's tank and tray cleaner. The sulfamic acid may be the one chemical not normally found in the darkroom, so the permanganate stain remover indicated above will likely be the best bet for those who have access to the chemicals. _ [o] -GH