U of S | Mailing List Archive | alt-photo-process-l | Re: Strength of bleach

Re: Strength of bleach

Dear John,

IRC, the label was saying 55% sodium hypochlorite + perfume + surfactant. It's used by diluting it as following: 1 glass (~ 200 ml) into 20 l water. It's common household bleach that I purchased in the supermarket. Will look at the label (closely) once more when I get home -> maybe I wasn't able see the dot between the fives (the writing was quite small)...


Quoting John Grocott <john.grocott403@ntlworld.com>:

John Grocott wrote

''This bleach method has worked very well for me for many years, probably because gum is not used in my Direct Carbon process. At the dilution of 25ml to 1 Litre water (1/40 th) there is practically no odour. Not even as much as when its used in the washing of clothes and drains etc., in the houshold.''

The label on my concentrated bleach bottle states ''Contains less than 5 % chlorine based bleaching agent.

Loris, you say here you have 55 % bleach. Is it houshold stuff you buy in the supermarket ? Or something mixed up in your lab ? I have never seen such a high strength bleach, anywhere ! !

Please could you check ?

Ciao. John - Photographist - London - UK

----- Original Message -----
From: "Loris Medici" <mail@loris.medici.name>
To: <alt-photo-process-l@usask.ca>
Sent: Saturday, December 01, 2007 6:11 PM
Subject: Re: Bleach-development with gum

Quoting Katharine Thayer <kthayer@pacifier.com>:

It's interesting to me that
such a strong bleach you're using doesn't just take the image right off
the paper.
Well, since I dilute it by mixing 20ml into 1000ml of water, the
actual strength is something like 1%. I can barely sense the odor of
hypochlorite when it is so much diluted (it would cause me to
vomit/faint otherwise).