PQ Stain

That's part of the fun.
My next bottle of ID-62 (paper) will be a concentrate mixed with absolute
ethanol (I'm one of the lucky few that can buy this stuff at about US$1 a
liter), carbonate+ sulfite added at use time...

Jorge

"Dennis O'Connor" wrote in
:

I just had an out of town, 'acquaintance / photographer / accomplished
printer', in my darkroom so I could develop a roll of film that he
used to test a camera he was thinking of buying... When I swung open
the cupboard doors and there stood cans of gas line antifreeze, Red
Devil Lye, 20 Mule Team Borax, Arm & Hammer Washing Soda, and Vitamin
C powder, he started mumbling, "No way... This is a joke, right?
Where's the D-76?"... Funny thing, after the negatives were hanging to
dry and we were leaving he was still mumbling, " . . & the goddam
negatives look great.. I don't believe this..."...

Sorta like the day he found the Santa Claus costume in dad's closet...
I'm not sure he will ever be the same...
denny

"Patrick Gainer" wrote in message Besides all
that, it makes more
interezting reading when I write about using antifreeze or brake
fluid in developers.

When I was a young gawd, was I ever that young? grad student and lab
assistant in the qual and quan labs, we had 95% Ethanol on the shelf... Some
evenings I/we would take a small beaker of that down the hall and around the
corner to the biochem lab where the nursing students had lots of OJ on
hand...
Now, nursing students in those days tended to be very straight laced and
anal compulsive due to the selection process... It was always amazing how
relaxed and friendly they became after a few hits of 95% in OJ...
denny

"Jorge Omar" wrote in message
...
That's part of the fun.
My next bottle of ID-62 (paper) will be a concentrate mixed with absolute
ethanol (I'm one of the lucky few that can buy this stuff at about US$1 a
liter),

Duh.
Why did I decide to become an EE?? (-:

Jorge

"Dennis O'Connor" wrote in
:

When I was a young gawd, was I ever that young? grad student and lab
assistant in the qual and quan labs, we had 95% Ethanol on the
shelf... Some evenings I/we would take a small beaker of that down the
hall and around the corner to the biochem lab where the nursing
students had lots of OJ on hand...
Now, nursing students in those days tended to be very straight laced
and anal compulsive due to the selection process... It was always
amazing how relaxed and friendly they became after a few hits of 95%
in OJ... denny

Dennis O'Connor wrote:

When I was a young gawd, was I ever that young? grad student and lab
assistant in the qual and quan labs, we had 95% Ethanol on the shelf... Some
evenings I/we would take a small beaker of that down the hall and around the
corner to the biochem lab where the nursing students had lots of OJ on
hand...
Now, nursing students in those days tended to be very straight laced and
anal compulsive due to the selection process... It was always amazing how
relaxed and friendly they became after a few hits of 95% in OJ...
denny

There used to be a guy in my lab (before my time) who would take swigs
of the absolute ethanol when the urge struck. Besides being painful
going down, the absolute stuff is no good for you -- they dehydrate it
by distilling with benzene to break the ethanol/water azeotrope. The
same guy would dilute glacial acetic acid in water to make a "refreshing
foot soak" in the summertime. Pure craziness.

Jordan

Jordan

Over here they use CaO (or that's what I think my father told me a looong
time ago).

See:

http://journeytoforever.org/biofuel_.../Mariller.html

at the end of the article.

Jorge

Jordan Wosnick wrote in
:


There used to be a guy in my lab (before my time) who would take swigs
of the absolute ethanol when the urge struck. Besides being painful
going down, the absolute stuff is no good for you -- they dehydrate it
by distilling with benzene to break the ethanol/water azeotrope. The
same guy would dilute glacial acetic acid in water to make a
"refreshing foot soak" in the summertime. Pure craziness.

Jordan

Patrick Gainer wrote


Patrick Gainer wrote

My interest was in sulfite-free developers.


WAS? Why such exotic compounds such as brake fluid and antifreeze?
At bedrock is the lifespan of at least the stock or concentrate. Why
not some other scavenger of oxygen? Perhape an oxalate or even one
of those used in preserving pharmaceuticals in water solution. Dan



In order to get the sulfite-free preservation of stock solutions one
could use ...

"One could use" as I suggested, perhaps an oxalate or one used
in preserving pharmaceuticals in water solution.
Finding an oxygen scavenging substitute for a sulfite may or may not
be possible. If the scavenger is too powerfull a reducing agent the
silver
in the emulsion would be totaly reduced by it.
I think there is likely a substitute for sulfite, which scavenges
oxygen, and is much less expensive than any of the various fluids
suggested although I don't know what it would be.
Dan

OK Jordan... Good memories - what an animal your guy was...
On the ethanol, yes they use toxic things to remove the water... No, the
toxic things are not present in analytic ethanol in significant
quantities... I used absolute ethanol (not the 95%) as a solvent for
preparing samples of hydrocarbons for the NMR and gas chromatograph machines
during research in the early 70's... Had there been more than microscopic
traces of benzene in the solvent it would have distorted the results, so I
know it was as close to pure as could be had in that period... Don't know
about now as I went into clinical medicine 30 years ago...
denny

"Jordan Wosnick" wrote in , the absolute stuff is no
good for you -- they dehydrate it
by distilling with benzene to break the ethanol/water azeotrope. The

It's probably just a tactic they use to scare us off the absolute
ethanol in any case. I think you could easily get away with a few ppm of
benzene undetected in NMR. Not sure about GC though.

In addition to the ethanol and acetic acid, this guy did things that
endangered the safety of others as well as himself. He wasn't long for
the lab.

Jordan

Dennis O'Connor wrote:
OK Jordan... Good memories - what an animal your guy was...
On the ethanol, yes they use toxic things to remove the water... No, the
toxic things are not present in analytic ethanol in significant
quantities... I used absolute ethanol (not the 95%) as a solvent for
preparing samples of hydrocarbons for the NMR and gas chromatograph machines
during research in the early 70's... Had there been more than microscopic
traces of benzene in the solvent it would have distorted the results, so I
know it was as close to pure as could be had in that period... Don't know
about now as I went into clinical medicine 30 years ago...
denny

"Jordan Wosnick" wrote in , the absolute stuff is no
good for you -- they dehydrate it

by distilling with benzene to break the ethanol/water azeotrope. The

Dan Quinn wrote:

Patrick Gainer wrote


Patrick Gainer wrote

My interest was in sulfite-free developers.


WAS? Why such exotic compounds such as brake fluid and antifreeze?
At bedrock is the lifespan of at least the stock or concentrate. Why
not some other scavenger of oxygen? Perhape an oxalate or even one
of those used in preserving pharmaceuticals in water solution. Dan

In order to get the sulfite-free preservation of stock solutions one
could use ...

"One could use" as I suggested, perhaps an oxalate or one used
in preserving pharmaceuticals in water solution.
Finding an oxygen scavenging substitute for a sulfite may or may not
be possible. If the scavenger is too powerfull a reducing agent the
silver
in the emulsion would be totaly reduced by it.
I think there is likely a substitute for sulfite, which scavenges
oxygen, and is much less expensive than any of the various fluids
suggested although I don't know what it would be.
Dan
Let me repeat. The glycol is not an oxygen scavenger. An oxygen
scavenger in place of sulfite in a water solution will still allow the
water to do what it does: ionize molecules. It will not keep those
ionized particles from interacting with one another and thus changing
the characteristics of the stock solution. Dissolving the solids in a
solvent that does not ionize them is about as close as one can come to
making a working solution directly from the solids wihout the
inconvenience of measuring each one individually. Measuring 0.05 grams
of phenidone is a pain and dissolving it in water is another. In fact,
all quantities of solids required to make a liter of a very good
developer are so small as to make consistent measurement difficult. That
is why we resort to stock solutions in the first place, and then
complain like the devil when they are unstable.

As for expense, a gallon of technical grade propylene glycol can be had
for about 16 US dollars + shipping. Using 20 ml for a liter of working
strength developer is not very expensive considering you get about 187
liters of developer out of your gallon. The technical grade is good
enough, as is technical grade l-ascorbic acid, available at $15/lb from
the same source, www.chemistrystore.com

Oxygen is not the major culprit, IMHO. It is water, without which the
oxygen cannot do its dirty work. If you want an oxygen scavenger, try
ascorbic acid in water solution. It will protect sodium sulfite from
oxidation, from what I hear.

Please consider my foregoing comments not as flaming, but as fatherly
advice. Maybe even grandfatherly. I have celebrated my 40th birthday 37
times already.

braggert!

denny

"Patrick Gainer" wrote in message . I have celebrated my
40th birthday 37
times already.