RE: EDTA

Here is a less lame response.

The disodium when mixed with water will give you a pH of close to 7 (
perhaps a bit lower) where the tetra will give you a pH around 10. These
are values for mixed solutions used in clearing baths. I will use the
disodium as a first bath ( pH more like that of many developers) and then
finish with a bath mixed with tetra for a final bath. This works well with
papers that have a buffer in them. I am working from memory here so check
the pH values, but these should be close. The disodium generally cost more
in my experience, so I'd start with the tetra if that matters.

Eric Neilsen
http://ericneilsenphotography.com

> -----Original Message-----
> From: Ryuji Suzuki [mailto:rs@agx.st]
> Sent: Friday, February 25, 2005 9:59 PM
> To: alt-photo-process-l@sask.usask.ca
> Subject: Re: EDTA
>
> From: Martin Angerman <paleophoto@adelphia.net>
> Subject: Re: EDTA
> Date: Fri, 25 Feb 2005 19:17:27 -0800
>
> > They both work the same. If sodium or potassium affects your
> > chemistry, purchase accordingly. There will be a slight difference
> > in the concentrations you need. This may not even be needed, as
> > this is usually in excess.
>
> What a lame response to make in Friday night, I know, but I'm busy
> tasting too many bottles (of spirits) I brought from NH this week.
>
> Disodium and tetrasodium EDTA have different degrees of acidity and
> one should check the original formula before buying them. Either one
> can be used if you are willing to adjust for the difference in
> acidity, but, buying the form specified in the formula is the easiest.
>
> Non-lame responses may have to wait for Monday after lunch hours...
> --
> Ryuji Suzuki
> "Well, believing is all right, just don't let the wrong people know
> what it's all about." (Bob Dylan, Need a Woman, 1982)
Received on Fri Feb 25 22:25:59 2005