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#21
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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. |
#22
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PQ Stain
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), |
#23
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PQ Stain
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 |
#24
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PQ Stain
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 |
#25
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PQ Stain
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 |
#26
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PQ Stain
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 |
#27
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PQ Stain
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 |
#28
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PQ Stain
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 |
#29
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PQ Stain
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. |
#30
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PQ Stain
braggert!
denny "Patrick Gainer" wrote in message . I have celebrated my 40th birthday 37 times already. |
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