Re: Re:

[Richard Knoppow <dickburk@ix.netcom.com>]

----- Original Message ----- 
From: "jfulton" <jfulton@sfai.edu>
To: <alt-photo-process-l@usask.ca>
Sent: Thursday, November 08, 2007 3:45 PM
Subject: Re:


> Scott:
> I'm sure Richard or Ryuji will know far more than I . . 
> but it is  primarily a concentrated alum and used as the 
> hardener in fixing  baths. From being an outdoors-man one 
> can use it as a flocculating  agent to clarify water:
> 1. treat water with concentrated chlorine crystals and 
> wait  overnight, and in the morning it'll be VERY chlorine 
> smelling
> 2. pour in a concentrated form of hydrogen peroxide such 
> as used in  hair salons (BUT beware as it can BURN or 
> oxide your skin) until the
> chlorine odor is gone . . you can put in a bit more and 
> it'll make  the water kinda effervescent
> 3. add a tsp of so of aluminum sulfate and the 
> flocculating (causing  to form into clumps) aspect of it 
> will take any of the portions, say, of
> algae or particulant matter and drop it to the bottom 
> and/or make  it/them easy to filter out.
>
> It is quite astringent and you might've come across in the 
> form of a  styptic pencil if you cut yourself shaving.
>
> Cheers
> Jack
   BTW, I not in the same class as Ryuji. I have a 
rudimentary knowledge of photographic chemistry, I think his 
is profound.
   The "alum" used in most hardening fixers is potassium 
aluminum sulfate, that sounds like the stuff above. Its also 
known as white alum. So called chrome alum is also used 
occasionally. The alum in the name comes from the similar 
use as a photographic hardener to white alum but it is 
potassium chromium sulfate and has no aluminum in it.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com