[pure-silver] Re: Adding Pot Bromife to PC-TEA
- From: "Koch, Gerald" <gkoch02@xxxxxxxxxx>
- To: "'pure-silver@xxxxxxxxxxxxx'" <pure-silver@xxxxxxxxxxxxx>
- Date: Thu, 6 Jan 2005 13:35:41 -0500
-----Original Message-----
From: pure-silver-bounce@xxxxxxxxxxxxx [mailto:pure-silver-bounce@xxxxxxxxxxxxx]
On Behalf Of John Black
Sent: Thursday, January 06, 2005 1:02 PM
To: pure-silver@xxxxxxxxxxxxx
Subject: [pure-silver] Re: Adding Pot Bromife to PC-TEA
When you say it is grainier than than you would like to what film are you
refering? 5231 has the same RMS granularity as Plus-X. I find the grain with
this developer so fine that I have difficulty using a grain focuser.
You say disperse rather than dissolved? The ascorbic acid and Phenidone are
both soluble in TEA. You will have to heat the TEA to make them dissolve but
you will get a clear solution.
Using propylene glycol really cuts the viscosity of the TEA way down. My
experience with methanol is that Phenidone doesn't keep very well in it.
Jerry
> I was testing a new lens on one of my Nikons. The film was 35mm
> Eastman
5231
> ISO 80 rated at an EI of 125 and developed in the following developer
(diluted)
> 1+49 for 8 minutes at 22 C.
>
> Propylene glycol ....................... 50.0 ml Triethanolamine
> ........................ 50.0 ml
> Ascorbic acid .......................... 9.0 g
> Dimezone-S ............................. 0.3 g
> Potassium bromide ...................... 0.25 g
>
> Without the bromide there was an objectionable amount of fog and it
> was difficult to obtain sufficient contrast without too much density.
Hmmm.... My PC-TEA used G's recommended concentration of TEA that has twice as
much as this. I dispersed (can't really use the term dissolved) the P and C in
100ml TEA with no PrGL. I was put off by the viscous nature of the TEA so I
thinned it out 1:1 with dry methanol. The resultant mixture I diluted 1:25 for
use. Your modification cuts the TEA in half, which should be fine as it is
somewhat in excess in G's formulas.
I agree that the unmodified PC/TEA as per Gainer gives some fog but is quite
active and shows a good CI and speed. In my hands, though, it is grainier than
I would like (yes, I'm probably too anal about it) resulting from a higher pH
than I would like. If you dilute the PC/TEA in water that has 5/5
(gm/L) sulfite/boric acid, the pH come down and the fog disappears. All this is
for 35mm though, and I would not hesitate to use the unmodified Gainer
formulations for RF and LF.
BTW, my TEA is reagent grade from Sigma so it should behave normally.
JB
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