Rodinal

Dan Quinn wrote:

John wrote


I believe the original formula was published around 1905

Water @ 125F 750ml
p-Aminophenol Hydrochloride 100g
Pot. metabisulfite 300g
Water to make 1.0L

50% Hydroxide Solution
Water @ 65F 75ml
Sod. Hydroxide 50
Water to make 100ml

From my site of course ;)

Nice site but where are the galleries?

One other formula of a Rodinal type has been posted this thread.
Perhaps you saw it: 20gr p-AM, 60gr metabisufite, and 28gr KOH per
400ml. A complete discription of it's compounding is included.
Contrast that mix with Formulary's 50gr, 150gr, and 215gr per
1000ml. On a liter basis the above posted formula has 70gr of KOH.
Where does the Formulary and Jacks Pic come up with 215gr? 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

Dan,
The standard abbreviation for grams is "g". The abbreviation "gr" stands
for grains. I'm sure you meant grams. Some Englishman might not be sure.

I have used the Formulary kit. When you mix that, you do not necessarily
use all of the KOH. You are instructed to add it little by little until
only a few crystals are left.

If you are dealing with USP chemicals, perhaps you can specify exact
amounts of each chemical that will leave a few crystals. Photography
does not, as a rule, need nor even profit from the use of USP chemicals,
or scales that weigh to the milligram, either. If you can do what
amounts to titration until an observable reaction happens, there are
lots of uncertainties you can work around.

Anything I say here is my opinion. I don't have the fear of failure that
some others do, but my experience has been that as many failures happen
when I follow to the letter another's instructions as when I use my
teaspoons and "salt to taste".

I'm preaching anyway, aren't I.

John wrote

I believe the original formula was published around 1905

Water @ 125F 750ml
p-Aminophenol Hydrochloride 100g
Pot. metabisulfite 300g
Water to make 1.0L

50% Hydroxide Solution
Water @ 65F 75ml
Sod. Hydroxide 50
Water to make 100ml

That sodium 50g/40 ratio is close to the potassium 70g/56 I
mentioned in my last post. The 40 and 56 are the gram formula weights.
Yet the formula above has twice the p-AP and 85g more K. metabisulfite
of any formula yet encountered for a Rodinal type developer. So the
above formula has, by comparison , very little Na or K OH.
Also the above formula does not maintain the same ratio of other Rodinal
types when p-AP and metabisulfite are compared.
All that acid and so little OH. I doubt the above formula will work.
BTW, another p-AP product on the market is Calbe R-09. Dan

(Dan Quinn) wrote in message . com...
John wrote

I believe the original formula was published around 1905

Water @ 125F 750ml
p-Aminophenol Hydrochloride 100g
Pot. metabisulfite 300g
Water to make 1.0L

50% Hydroxide Solution
Water @ 65F 75ml
Sod. Hydroxide 50
Water to make 100ml

That sodium 50g/40 ratio is close to the potassium 70g/56 I
mentioned in my last post. The 40 and 56 are the gram formula weights.
Yet the formula above has twice the p-AP and 85g more K. metabisulfite
of any formula yet encountered for a Rodinal type developer. So the
above formula has, by comparison , very little Na or K OH.
Also the above formula does not maintain the same ratio of other Rodinal
types when p-AP and metabisulfite are compared.

Correction: ...the above formula DOES maintain the same ratio... Dan

All that acid and so little OH. I doubt the above formula will work.
BTW, another p-AP product on the market is Calbe R-09. Dan

On 26 Mar 2004 02:50:05 -0800, (Dan Quinn) wrote:

I believe the original formula was published around 1905

Water @ 125F 750ml
p-Aminophenol Hydrochloride 100g
Pot. metabisulfite 300g
Water to make 1.0L

50% Hydroxide Solution
Water @ 65F 75ml
Sod. Hydroxide 50
Water to make 100ml

From my site of course ;)

Nice site but where are the galleries?

LOL ! It's turned out to be a rather busy year for me ! Do you
have children ?

Also note that I'm adding the "noframes" section which is
another 1400+ pages to get working.

One other formula of a Rodinal type has been posted this thread.
Perhaps you saw it: 20gr p-AM, 60gr metabisufite, and 28gr KOH per
400ml. A complete discription of it's compounding is included.
Contrast that mix with Formulary's 50gr, 150gr, and 215gr per
1000ml. On a liter basis the above posted formula has 70gr of KOH.
Where does the Formulary and Jacks Pic come up with 215gr?

The 215 gram of KOH is mixed into 500ml of water to give the
21.5% solution used to titrate the stock. The percentage doesn't
matter that much though it might have been used for saftey concerns as
a 50% stock soluton of KOH could be real nasty. Also note that one
will usually use virtually the same amount of alkali to titrate a
given quantity of acid. I say "virtually" as the strength of bisulfite
seems to vary a little unless one is consistently using fresh
chemicals.

Regarding where the 215g figure came from, unfortunately I
can't find a source.

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 ?

Regards,

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

"Hektor Gonzal" wrote in message
...
Hi all,

I do not develop not more than 1-2 rolls of film in a week, shelf life is
important to me.

I don't use a lot of it, but my bottle I dated 24/12/01 on opening is still
fine, although alomst empty.

I have another question. I use 300 ml of working solution to develop 35
mm.
films. the 1+50 dilution requires really little amounts of stock
developer.
Is there a threshold for the stock amount to be used, any minumum limits?

Numbers get bandied around, official and unoffical. I personally use
Rodinal 1:100 so use 3ml in 300ml for 35mm. 5ml in 500ml for MF. I have
played around with 1:400 (0.75ml in 300ml) for stand development (which
worked)


Cheers, Nige

On 3/25/2004 11:33 AM John spake thus:

On Wed, 24 Mar 2004 09:08:12 -0600, (jjs)
wrote:

Thanks for that, and your other post, Dan. I had an awful time finding
small glass bottles. Even the pharamcists quit using them. So I ordered
from Boston Round and by your post it appears that I guessed well.

Why not just use the 250~300 ml plastic cough syrup bottles
that any pharmacy has ? I believe that most are made of PET which is
an excellent storage medium.

Now's as good a time as any to bring up this sticky question: just how
permeable *are* plastic bottles, anyway? I hear it said, over and over again
like a mantra, that plastic bottles are no good because they let oxygen
through. But is this really true? And is it true for *all* plastics?

I suspect not, but can't say for sure since I'm not a plastics expert. What is
the permeability of various plastics? PET? HDPE? others? Anyone know for sure?


--
.... but never have I encountered a guy who could not be bothered
to make his own case on his own show.

- Eric Alterman on his appearance on Dennis Miller's bomb of a show
on CNBC (3/17/04)

Check out Ryuji's site:

http://silvergrain.org/Photo-Tech/ch...misnomers.html

He is a chemist.
_________________
Ready, Fire, AIM.
Bruce
Brooklyn, N.Y.

On 3/27/2004 12:12 PM Bruce spake thus:

Check out Ryuji's site:

http://silvergrain.org/Photo-Tech/ch...misnomers.html

He is a chemist.

Thanks.

From his page on plastic bottles
(http://silvergrain.org/Photo-Tech/plastic.html):

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


PET (polyethylene terephthalate) is used as a clear (colorless or tinted)
bottle material in bottled water products. It has very small permeability
to oxygen and nitrogen.

Use PET for developers. Use PET or HDPE for most other chemicals. If you
store acetic acid stop bath in concentrated form, use HDPE. If PVC coated
cap is available, use it by all means.

My bottles of D-76, Microphen, and various other experimental formula are
still alive and as vigorous in filled and tightly capped 500ml PET bottles
after two years!

So take that, ye who say that only glass can be used to store photo chemicals!


--
.... but never have I encountered a guy who could not be bothered
to make his own case on his own show.

- Eric Alterman on his appearance on Dennis Miller's bomb of a show
on CNBC (3/17/04)

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

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 take that, ye who say that only glass can be used to store photo
chemicals!

I added a line. I hope you don't mind. What ever is used be sure
the caps are of the Polycone/Polyseal type. Dan