Rodinal

Dan Quinn wrote:

John wrote

Am I over-looking something somewhere? I've not done the arithmatic
yet but would not be surprised if the 70gr gives the 3% KOH
Agfa claims on their bottle. Dan

70gr is quite a bit of KOH. Also aren't their bottles 500 ml ?

I've read Dr. M. Gudzinowicz lengthy post where-in he compares
one of your concoctions with Rodinal.
In his conclusion he makes the observation that the new Rodinal
has no "sludge". Although he is unclear I believe he is saying that
the ph has been uped. I think that may account for the 3% KOH. That
is only .3g/liter at 1:100 or .005 molar. He is not happy with that.
How much that raises the ph I could'nt say.
Metol, p-AP, and Glycin now make-up my list of developing
agents which will do it all, film/print, acting individualy.
My minimalist approach may be rewarding. Dan
Where is that post by M. Gudzinowicz?
Did he compare one of my concoctions with Rodinal?

Pat Gainer

Patrick
These are old posts, and AFAIR he did not do any compare of yours
concoctions with Rodinal (more even so if you're thinking of PG).
They have been posted in R.P.D. about 1999~2000.

Jorge

Patrick Gainer wrote in news:406728DB.14D0D166
@rtol.net:

Where is that post by M. Gudzinowicz?
Did he compare one of my concoctions with Rodinal?

Pat Gainer

Dan Quinn wrote:

David Nebenzahl wrote


Why manufacturers and chemists recommend glass bottles for storing
photographic chemicals has a lot to do with idiot-proof factors. With a
little attention, inexpensive and convenient plastic bottles can be used
for most photographic chemical storage without compromising their shelf
life.

Plastic materials and chemical properties

material gas permeability acid resistance max usable temp
---------------------------------------------------------------
PET (PETE) very good reasonable 60°C
HDPE poor good 120°C
PVC very good reasonable 70°C
LDPE very poor good 80°C
PVdc (Saran wrap) excellent reasonable 65°C



Glass excellent excellent way up there


So you can use HDPE or even LDPE, just wrap it in Saran wrap?

:-)

BertS wrote in message ink.net...
Dan Quinn wrote:

David Nebenzahl wrote


Why manufacturers and chemists recommend glass bottles for storing
photographic chemicals has a lot to do with idiot-proof factors. With a
little attention, inexpensive and convenient plastic bottles can be used
for most photographic chemical storage without compromising their shelf
life.

Plastic materials and chemical properties

material gas permeability acid resistance max usable temp
---------------------------------------------------------------
PET (PETE) very good reasonable 60°C
HDPE poor good 120°C
PVC very good reasonable 70°C
LDPE very poor good 80°C
PVdc (Saran wrap) excellent reasonable 65°C



Glass excellent excellent way up there


So you can use HDPE or even LDPE, just wrap it in Saran wrap?

Or a wide mouth glass jar. Jars take lids and I've not seen any
Poly seal/cone lids. I know, those canning rings with seal equipped
lids should work. I think they are made in gallon size. Dan

Patrick Gainer wrote

Where is that post by M. Gudzinowicz?

From this NG search for, "my home brew" . The doctor is number
one.

Did he compare one of my concoctions with Rodinal?

He has positioned one of Mr. J. Douglas' formulas on the
operating table and proceeds to dissect it. Dan

On 29 Mar 2004 00:08:17 -0800, (Dan Quinn) wrote:

From this NG search for, "my home brew" . The doctor is number
one.

Boy do I remember that thread !


Regards,

John S. Douglas, Photographer - http://www.darkroompro.com
Please remove the "_" when replying via email

Patrick Gainer wrote:

Dan Quinn wrote:

John wrote


Am I over-looking something somewhere? I've not done the arithmatic
yet but would not be surprised if the 70gr gives the 3% KOH
Agfa claims on their bottle. Dan

70gr is quite a bit of KOH. Also aren't their bottles 500 ml ?

I've read Dr. M. Gudzinowicz lengthy post where-in he compares
one of your concoctions with Rodinal.
In his conclusion he makes the observation that the new Rodinal
has no "sludge". Although he is unclear I believe he is saying that
the ph has been uped. I think that may account for the 3% KOH. That
is only .3g/liter at 1:100 or .005 molar. He is not happy with that.
How much that raises the ph I could'nt say.
Metol, p-AP, and Glycin now make-up my list of developing
agents which will do it all, film/print, acting individualy.
My minimalist approach may be rewarding. Dan

Where is that post by M. Gudzinowicz?
Did he compare one of my concoctions with Rodinal?

Pat Gainer

Patrick, I read MG's post and it was interesting that he went into the concept
of how to maximize the amount of p-aminophenol in Rodinal. I also read your
article where you talk about dissolving some developing agents in hot TEA to
obtain very long lived stock solutions. I wonder if p-aminophenol can be
dissolved in this way and what the results would be. Perhaps the grain can be
tamed this way?

Just speculating, I am not a chemist.

Bert

nicholas wrote:
BertS wrote:



Patrick, I read MG's post and it was interesting that he went into the
concept of how to maximize the amount of p-aminophenol in Rodinal. I
also read your article where you talk about dissolving some developing
agents in hot TEA to obtain very long lived stock solutions. I wonder
if p-aminophenol can be dissolved in this way and what the results
would be. Perhaps the grain can be tamed this way?

Just speculating, I am not a chemist.

Bert, I am not a chemist either but I have tried and used for awhile
what you are talking about. Well, not exactly but close.

I made a concoction of Propylene Glycol and p-Aminophenol (with the
weights for p-Aminophenol.HCl as well) and Vitamin C and gave the
ingredients for it in the pdf I made of Patrick's developers. I had been
using the water based version for some time and enjoyed the very fine
grain and sharp looking prints I got from it. However I could not get
the developer to last in concentated solution reliably for more than a
couple of months without some kind of loss of activity.

For this reason I stopped using this developer. However sometime last
year I tried concocting something with the new 'base', first with
antifreeze (ethylene glycol) and then with propylene glycol. I got good
results and used it for awhile (some months) to good effect. For some
reason the grain seemed even finer than with the water based developer...

Whether or not TEA works I dont know, worth a try however...

Email me without the capital letters and I will forward the pdf onto you
if you would like to try it.

Regards,
Nicholas

Nicholas, I received the pdf and found it interesting. I will add it to my
list of things to do or try.

Thanks a million!

Bert