John Melanson (john@audiologic.com)
Mon, 26 Jul 1999 14:14:19 -0600
As an example, for a pH aproximatly (very crude) halfway between borax and
meta, add half the NaOH.
For a more accurate analysis, us a ph meter or there is a table in the CRC
chemical handbook. I think it's under standard buffers, or some such
heading. But for photo use, borax with more hydroxide added makes higher
pH, and borax with boric acid makes lower pH. It can be tuned, and is very
reproducable. Borax is a great buffer because it can "soak up" a lot of
acid or base without huge swings in pH. This allows continous tuning of a
developer speed, and is far more stable than changing the dilution of the
alkali.
> -----Original Message-----
> From: FotoDave@aol.com [mailto:FotoDave@aol.com]
> Sent: Monday, July 26, 1999 1:32 PM
> To: alt-photo-process-l@sask.usask.ca
> Subject: Re: sodium metaborate, to make?
>
>
> In a message dated 7/26/99 11:31:08 AM Pacific Daylight Time,
> john@audiologic.com writes:
>
> > All the borates are great buffer, you can vary the pH continuously, and
> > repeatably.
> >
>
> Could you explain the above a little more? Thanks!
>
>
> Dave S
>
This archive was generated by hypermail 2.0b3 on Thu Oct 28 1999 - 21:40:38