Re: reversal bleach in SF

From: Ed Inman (email suppressed)
Date: Thu Nov 30 2006 - 17:17:23 PST

All B&W bleaches contain hazardous chemicals and should be mixed and handled by properly trained individuals with due care. The formula for R-9 (orange) bleach is not terribly difficult, however:

Per one liter of water add 9.5 grams of Potassium Dichromate and
12 ml of concentrated Sulfuric Acid (or 25 ml of the 48 percent sulfuric acid as sold by Photographers Formulary). Always add acid to water--NEVER water to acid. Once exhausted, bleach solution should be discarded as hazardous waste.

One source for the chemicals (and about any other photo chemical you could ever want:

It is not generally illegal to ship chemicals for photochemistry purposes but extra charges may apply and the company will require you to fill out a DEA form stating your intended use (and require you to provide a scan of your current ID) before they will ship the acid. The form is provided at their website.

-----Original Message-----
>From: Scott Stark <email suppressed>
>The orange reversal bleach must be made from
>scratch... The Art Institute does it this way as Kodak
>stopped making it. It has both sulfuric acid and and
>potassium dichromate-nasty chemicals. I believe that
>it might be possible to purchase these on Ebay, but it
>can probably be purchased from several chemical
>companies. The problem is shipping... it might
>actually be illegal to ship hazardous chemicals such
>as these by post...

For info on FrameWorks, contact Pip Chodorov at <email suppressed>.