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pure ammonium thiosulfate fixer
Dear Readers--
I have a question: is there anything wrong with the use of pure ammonium thiosulfate as a fixer for pyro-developed film? (I use 35mm Tri-X mostly). I have some of the "60% ammonium thiosulfate" made by Formulary. Is it possible to use borax instead of sodium metaborate in mixing a fixer? How much? Anchell & Troop list a recipe with sodium metaborate, but not borax. Thanks kindly. |
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pure ammonium thiosulfate fixer
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#3
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pure ammonium thiosulfate fixer
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#4
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pure ammonium thiosulfate fixer
"Travis C. Porco" wrote in message ... Dear Readers-- I have a question: is there anything wrong with the use of pure ammonium thiosulfate as a fixer for pyro-developed film? (I use 35mm Tri-X mostly). I have some of the "60% ammonium thiosulfate" made by Formulary. Is it possible to use borax instead of sodium metaborate in mixing a fixer? How much? Anchell & Troop list a recipe with sodium metaborate, but not borax. Thanks kindly. I am not a believer in alkaline fixers. As far as effectiveness of fixing the pH does not matter. If you don't want to use acid fixer neutral fixer works just fine and will preserve the stain image as well as an alkaline fixer. Be careful not to confuse the desired stain image with overall staining, which is not desirable. Pyro negatives should be pretty much stain free in the clear areas and have a proportional stain in the image. I think many of those who complain of lack of stain are really looking at overall staining. Fixer needs to have sodium sulfite in it both to protect the thiosulfate from oxidation and to prevent staining from carried over developer which will remain active in neutral or alkaline fixing baths for long enough to cause problems. Sulfite is slightly alkaline anyway. You don't need much, perhaps as little as 5 grams per liter of working solution. Most acid fixers have about 15 grams per liter but need it because the sulfite prevents decomposition of the thiosulfate by the acid. Sodium metaborate is a poor buffer despite Kodak's claims so Borax is actually a better choice if you really want to increase the pH. Tri-X is similar to T-Max in that it needs longer fixing than most other films. Check the clearing time and fix for three times that time. Use a two bath system to insure complete fixing, fix in each bath for half the total time. Ammonium thiosufate is not very stable in powder form so it usually supplied as a 60% liquid concentrat. -- --- Richard Knoppow Los Angeles, CA, USA |
#5
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pure ammonium thiosulfate fixer
Thanks kindly to you and the others who replied; I may try it both without
the sulfite and with it and see what happens. Is there a "standard" recipe for ammonium thiosulfate/borax/sodium sulfite? Also: Anchell & Troop are down on sodium thiosulfate. If you mix up a developer with ammonium thiosulfate, sodium metaborate, and sodium sulfite, it's still got a lot of sodium in it. Is it just good to have less sodium, or is it good to have the ammonium present, or does it just plain not matter? Final question. I've seen some bottles of Formulary TF-4 with a thick layer of precipitate on the bottom. Does this indicate that the bottle is absolutely no good, or could it be redissolved? Thanks again! In article . net, Richard Knoppow wrote: "Travis C. Porco" wrote in message ... Dear Readers-- I have a question: is there anything wrong with the use of pure ammonium thiosulfate as a fixer for pyro-developed film? (I use 35mm Tri-X mostly). I have some of the "60% ammonium thiosulfate" made by Formulary. Is it possible to use borax instead of sodium metaborate in mixing a fixer? How much? Anchell & Troop list a recipe with sodium metaborate, but not borax. Thanks kindly. I am not a believer in alkaline fixers. As far as effectiveness of fixing the pH does not matter. If you don't want to use acid fixer neutral fixer works just fine and will preserve the stain image as well as an alkaline fixer. Be careful not to confuse the desired stain image with overall staining, which is not desirable. Pyro negatives should be pretty much stain free in the clear areas and have a proportional stain in the image. I think many of those who complain of lack of stain are really looking at overall staining. Fixer needs to have sodium sulfite in it both to protect the thiosulfate from oxidation and to prevent staining from carried over developer which will remain active in neutral or alkaline fixing baths for long enough to cause problems. Sulfite is slightly alkaline anyway. You don't need much, perhaps as little as 5 grams per liter of working solution. Most acid fixers have about 15 grams per liter but need it because the sulfite prevents decomposition of the thiosulfate by the acid. Sodium metaborate is a poor buffer despite Kodak's claims so Borax is actually a better choice if you really want to increase the pH. Tri-X is similar to T-Max in that it needs longer fixing than most other films. Check the clearing time and fix for three times that time. Use a two bath system to insure complete fixing, fix in each bath for half the total time. Ammonium thiosufate is not very stable in powder form so it usually supplied as a 60% liquid concentrat. |
#6
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pure ammonium thiosulfate fixer
"Travis C. Porco" wrote: Thanks kindly to you and the others who replied; I may try it both without the sulfite and with it and see what happens. Is there a "standard" recipe for ammonium thiosulfate/borax/sodium sulfite? Also: Anchell & Troop are down on sodium thiosulfate. If you mix up a developer with ammonium thiosulfate, sodium metaborate, and sodium sulfite, it's still got a lot of sodium in it. Is it just good to have less sodium, or is it good to have the ammonium present, or does it just plain not matter? Final question. I've seen some bottles of Formulary TF-4 with a thick layer of precipitate on the bottom. Does this indicate that the bottle is absolutely no good, or could it be redissolved? Thanks again! That's the way it comes. Shake it well if you're only going to mix part of it. When you dilute it 1+3 or more, it clears up. |
#7
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pure ammonium thiosulfate fixer
On Thu, 22 Apr 2004 23:33:52 +0000 (UTC),
(Travis C. Porco) wrote: Is there a "standard" recipe for ammonium thiosulfate/borax/sodium sulfite Just mix F24 and leave out the bisulfite. Regards, John S. Douglas, Photographer - http://www.darkroompro.com Please remove the "_" when replying via email |
#8
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pure ammonium thiosulfate fixer
If you just want to fix a few films or prints, 180ml of 60% ammonium
thiosulfate in water works fine. But mix it just before use, it deteriorates quickly. Sodium sulfite is used as a preservative. I like the Kodak F-34 formula as a non-hardening fixer. Water 700 ml Ammonium thiosulfate, 58% 185 ml Sodium sulfite, anh. 10 g Sodium bisulfite 8.4 g Water to make 1 l It was originally intended as the fixer for Eastman 5247 motion picture film, but it works very well for regular film and prints. The pH is only 6.5 - near neutral - so washing should not be a problem. If you must have an alkline fixer, 200 ml of 60% ammonium thiosulfate plus 20 g of sodium sulfite per liter will probably do, but I think a fixer should be slightly acid to make the preservative work properly and to prevent unintended stains. "Travis C. Porco" wrote in message ... Dear Readers-- I have a question: is there anything wrong with the use of pure ammonium thiosulfate as a fixer for pyro-developed film? (I use 35mm Tri-X mostly). I have some of the "60% ammonium thiosulfate" made by Formulary. Is it possible to use borax instead of sodium metaborate in mixing a fixer? How much? Anchell & Troop list a recipe with sodium metaborate, but not borax. Thanks kindly. |
#9
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pure ammonium thiosulfate fixer
On Fri, 23 Apr 2004 00:06:19 -0500, John
wrote: On Thu, 22 Apr 2004 23:33:52 +0000 (UTC), (Travis C. Porco) wrote: Is there a "standard" recipe for ammonium thiosulfate/borax/sodium sulfite Just mix F24 and leave out the bisulfite. Kodak's F-24 Fixer Water @ 125F 750ml Sod. Thiosulfate 240g Sod.Sulfite 10g Sod. Bisulfite 25g Water to make 1.0L Regards, John S. Douglas, Photographer - http://www.darkroompro.com Please remove the "_" when replying via email |
#10
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pure ammonium thiosulfate fixer
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