If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
single bath sodium sulfide toner?
Hello All,
I have been reading lots of posts about sepia toners, and I wonder why it is not possible to simply immerse a print in solution of sodium sulfide to get sepia tone? This should convert the silver to silver sulfide, surely? All formulae so far seem to suggest that the print should be bleached and "redeveloped" in a "brown toner" which essentially gives sulfide. I have been using thiourea toner bleach and redevelop), and got yellow/brown colour, but want to avoid using Thiourea. I hope sodium sulfide is a lesser evil. Thanks, Sreenath |
#2
|
|||
|
|||
single bath sodium sulfide toner?
"Lloyd" Lloyd AT the-wire DOT com wrote
Is the toxicity of thiourera really a problem? MSDS indicates: Thiourea is a carcinogen in rats. Most things are carcinogens in rats given a high enough dose. Nobody has tried chili peppers yet, but I'll bet... LD50 (1/2 the rats die) is ~100mg/kg or 10gm for a 220 lb. man. Reacts (sometimes violently) with fatty acids. So does soap. Should lower your cholesterol. No safe level has been established. It occurs naturally. Like, man, it's organic -- so like, it's got to be good for you. Heavy, yeah. Hasn't damaged my brain, like ... yeah, like, like ... where were we, man? -------- If I was worried I would use a smelly sulfide toner. I am not worried; but then a whiff of rotten egg doesn't upset me - brings back memories of the school cafeteria. -- Nicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. Remove spaces etc. to reply: n o lindan at net com dot com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ |
#3
|
|||
|
|||
single bath sodium sulfide toner?
Lloyd wrote:
On 27 Jul 2004 22:53:51 -0700, (sreenath) wrote: Just my thoughts, since hydrogen sulfide gas is an unpleasantness... Hydrogen sulfide is much more than an unpleasantness -- it's more toxic than hydrogen cyanide, and in concentrations well below the toxic level will burn out the receptors in your nose so you can't smell it at all, meaning you'll quit smelling it before it gets strong enough to kill you. -- I may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. |
#4
|
|||
|
|||
single bath sodium sulfide toner?
On Fri, 30 Jul 2004 11:43:05 GMT, Donald Qualls
wrote: Lloyd wrote: On 27 Jul 2004 22:53:51 -0700, (sreenath) wrote: Just my thoughts, since hydrogen sulfide gas is an unpleasantness... Hydrogen sulfide is much more than an unpleasantness -- it's more toxic than hydrogen cyanide, and in concentrations well below the toxic level will burn out the receptors in your nose so you can't smell it at all, meaning you'll quit smelling it before it gets strong enough to kill you. jul3004 from Lloyd Erlick, Yes, the fact it numbs out the smell sensors has led to deaths in mine accidents. But hydrogen sulfide gas starts to be a nuisance long before it gets to danger levels. You don't need to use sodium sulfide -- just fill up on some nice baked beans, canned if possible, and head into the darkroom, close that door... Anyway, darkroom smell abatement program in effect around here. No hydrogen sulfide, sulfur dioxide, acetic acid, etc etc... regards, --le ________________________________ Lloyd Erlick Portraits, Toronto. voice: 416-686-0326 email: net: www.heylloyd.com ________________________________ |
#5
|
|||
|
|||
single bath sodium sulfide toner?
On Fri, 30 Jul 2004 11:43:05 GMT, Donald Qualls
wrote: Lloyd wrote: On 27 Jul 2004 22:53:51 -0700, (sreenath) wrote: Just my thoughts, since hydrogen sulfide gas is an unpleasantness... Hydrogen sulfide is much more than an unpleasantness -- it's more toxic than hydrogen cyanide, and in concentrations well below the toxic level will burn out the receptors in your nose so you can't smell it at all, meaning you'll quit smelling it before it gets strong enough to kill you. jul3004 from Lloyd Erlick, Yes, the fact it numbs out the smell sensors has led to deaths in mine accidents. But hydrogen sulfide gas starts to be a nuisance long before it gets to danger levels. You don't need to use sodium sulfide -- just fill up on some nice baked beans, canned if possible, and head into the darkroom, close that door... Anyway, darkroom smell abatement program in effect around here. No hydrogen sulfide, sulfur dioxide, acetic acid, etc etc... regards, --le ________________________________ Lloyd Erlick Portraits, Toronto. voice: 416-686-0326 email: net: www.heylloyd.com ________________________________ |
#6
|
|||
|
|||
single bath sodium sulfide toner?
Lloyd wrote:
On Fri, 30 Jul 2004 11:43:05 GMT, Donald Qualls wrote: Hydrogen sulfide is much more than an unpleasantness -- it's more toxic than hydrogen cyanide, and in concentrations well below the toxic level will burn out the receptors in your nose so you can't smell it at all, meaning you'll quit smelling it before it gets strong enough to kill you. jul3004 from Lloyd Erlick, Yes, the fact it numbs out the smell sensors has led to deaths in mine accidents. It's also one of the more common causes of death on small-company fishing boats. Lose refrigeration, fish in the hold start to spoil, captain sends a man in to shovel it out. Man doesn't come back, doesn't answer, captain sends in another man. The record is, I believe, six men dead from hydrogen sulfide, one after another, last one was the captain. But hydrogen sulfide gas starts to be a nuisance long before it gets to danger levels. You don't need to use sodium sulfide -- just fill up on some nice baked beans, canned if possible, and head into the darkroom, close that door... There's a lot more than hydrogen sulfide in *that* nuisance gas... Anyway, darkroom smell abatement program in effect around here. No hydrogen sulfide, sulfur dioxide, acetic acid, etc etc... I rather like the smell of stop bath and fixer, but that's probably because it reminds me of some of my best times in and prior to high school. -- I may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. |
#7
|
|||
|
|||
single bath sodium sulfide toner?
Nicholas O. Lindan wrote:
"Lloyd" Lloyd AT the-wire DOT com wrote Is the toxicity of thiourera really a problem? MSDS indicates: Thiourea is a carcinogen in rats. Most things are carcinogens in rats given a high enough dose. Nobody has tried chili peppers yet, but I'll bet... LD50 (1/2 the rats die) is ~100mg/kg or 10gm for a 220 lb. man. Reacts (sometimes violently) with fatty acids. So does soap. Should lower your cholesterol. No safe level has been established. It occurs naturally. Like, man, it's organic -- so like, it's got to be good for you. Heavy, yeah. Hasn't damaged my brain, like ... yeah, like, like ... where were we, man? A recent discovery shows that the presence of scientits causes cancer in rats. LD50 (1/2 the rats die) is ~0.7 scientist/kg Bert ;-) |
#8
|
|||
|
|||
single bath sodium sulfide toner?
On Sat, 31 Jul 2004 02:23:21 GMT, Donald Qualls
wrote: .... I rather like the smell of stop bath and fixer, but that's probably because it reminds me of some of my best times in and prior to high school. .... jul3104 from Lloyd Erlick, I find the scent of non-acid fixer does the same for me. Just plain sodium thiosulfate dissolved in water smells very pleasant to me. And you can't smell it unless you go and sniff it. No filling the air with odor. (Iknow, acetic acid smells like french fries - if you're Canadian - and I even eat fries. But not all day long. The smell has worn on me.) regards, --le |
#9
|
|||
|
|||
single bath sodium sulfide toner?
On Sat, 31 Jul 2004 02:23:21 GMT, Donald Qualls
wrote: .... I rather like the smell of stop bath and fixer, but that's probably because it reminds me of some of my best times in and prior to high school. .... jul3104 from Lloyd Erlick, I find the scent of non-acid fixer does the same for me. Just plain sodium thiosulfate dissolved in water smells very pleasant to me. And you can't smell it unless you go and sniff it. No filling the air with odor. (Iknow, acetic acid smells like french fries - if you're Canadian - and I even eat fries. But not all day long. The smell has worn on me.) regards, --le |
#10
|
|||
|
|||
single bath sodium sulfide toner?
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
single bath sodium sulfide toner? | Lloyd | In The Darkroom | 10 | July 31st 04 01:28 PM |
Gainer paper developer? | Gene Johnson | In The Darkroom | 15 | June 6th 04 11:03 PM |
Add Kodak Brown to KRST? | Mike | In The Darkroom | 12 | May 5th 04 09:33 AM |
Fix bath test | piterengel | In The Darkroom | 8 | February 9th 04 12:42 AM |
Kodak rapid selenium capacity | Fred | In The Darkroom | 14 | February 4th 04 03:57 AM |