Re: Pyro shelf life?

Date view Thread view Subject view Author view

From: cor (cor@lumc.nl)
Date: 02/12/01-05:34:18 AM Z


Sandy King wrote:
. There have been a
> number of posts on this list and on the newsgroups that suggest that Rollo
> Pyro is indeed much less stable than PMK.
>
> So how long will stock solution A of Rollo Pyro last before oxidation
> causes it to go bad? I really don't know but personally would not trust it
> for more than about three months. Perhaps others have experience which
> indicates that it will last longer?

Sandy,

we exchanged some Emails about this in the past, and I think you are
right about these three months, it gets realy darkbrown, and even before
this colour cahnge I have the idea that the staining gets less intense
when the A part ages. Plus the fact that the A part has to age a couple
of days before use made me starting to switch to PMK (FP4 and HP5 4*5 in
a 2509 (?) drum). The first results were quite promising, but not enough
stain, so I have to prolong the developing time.

Anschell mentions that one can increase A with 30% to reduce the arial
oxidation in a JOBO , but shouldn't one also increase "B" with 30% to
maintain the buffered pH?

Best,

Cor


Date view Thread view Subject view Author view

This archive was generated by hypermail 2b30 : 03/06/01-04:55:39 PM Z CST