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rapid, non-hardening alkaline fixer, questions on formulae
I've researched on two other fixer formula because F-24 is a slow fixer. I
want a rapid fixer. Here are the formulae: Neutral rapid fixer ammonium thiosulfate (60% solution) 200ml sodium sulfite 15g sodium metabisulfite 5g water to make 1 liter + However, I've read that ammonium in fixer is not for open trays because of the ammonium fumes. ~ So, here is another formula, the TF-2 Alkaline Sodium Thiosulfate Fixer Distilled water 1000 ml Sodium Thiosulfate 250 g Sodium Sulfite (anhy) 15 g Sodium Metaborate 10 g TF-2 will wash out of negative and print materials more rapidly than will an acid fixer. In jackspcs.com, it was not indicated how long PRINTS should be fixed in this specific fixer (but it was indicated it should be washed for 30 minutes). My questions a 1. The resource for the neutral rapid fixer formula didn't indicate the length of time for fixing FB prints. How long should FB prints be fixed in neutral rapid fixer? 2. Which fixer (neutral rapid fixer, or TF-2 alkaline) would you recommend? 3. If TF-2, how many minutes does it take for FB prints to be fixed in this fixer? Someone told me it takes 10 minutes to fix prints with TF-2, but an online source stated it fixes films (3-5 minutes) and prints (no. of minutes not stated) faster than usual fixers; so I thought, if it fixes faster, then it should not be 10 minutes like a regular fixer. How long, really, does TF- 2 take to fix FB prints? 4. I assume that since ther is no alum in either formula, then these fixers are non-hardening fixers. Is my assumption right? 5. Would you know other rapid fixer formula/e that would work with FB prints? If you do, and if you recommend that fixer, please post the formula here. Bear with me as I am only beginning to learn mixing my own chemicals. I really hope you could help me. Thanks. -- +Shakti V. Message posted via PhotoKB.com http://www.photokb.com/Uwe/Forums.as...kroom/200610/1 |
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rapid, non-hardening alkaline fixer, questions on formulae
"Shakti V. via PhotoKB.com" u15922@uwe wrote in message news:67764ee139b1e@uwe... I've researched on two other fixer formula because F-24 is a slow fixer. I want a rapid fixer. Here are the formulae: Neutral rapid fixer ammonium thiosulfate (60% solution) 200ml sodium sulfite 15g sodium metabisulfite 5g water to make 1 liter + However, I've read that ammonium in fixer is not for open trays because of the ammonium fumes. ~ So, here is another formula, the TF-2 Alkaline Sodium Thiosulfate Fixer Distilled water 1000 ml Sodium Thiosulfate 250 g Sodium Sulfite (anhy) 15 g Sodium Metaborate 10 g TF-2 will wash out of negative and print materials more rapidly than will an acid fixer. In jackspcs.com, it was not indicated how long PRINTS should be fixed in this specific fixer (but it was indicated it should be washed for 30 minutes). My questions a 1. The resource for the neutral rapid fixer formula didn't indicate the length of time for fixing FB prints. How long should FB prints be fixed in neutral rapid fixer? 2. Which fixer (neutral rapid fixer, or TF-2 alkaline) would you recommend? 3. If TF-2, how many minutes does it take for FB prints to be fixed in this fixer? Someone told me it takes 10 minutes to fix prints with TF-2, but an online source stated it fixes films (3-5 minutes) and prints (no. of minutes not stated) faster than usual fixers; so I thought, if it fixes faster, then it should not be 10 minutes like a regular fixer. How long, really, does TF- 2 take to fix FB prints? 4. I assume that since ther is no alum in either formula, then these fixers are non-hardening fixers. Is my assumption right? 5. Would you know other rapid fixer formula/e that would work with FB prints? If you do, and if you recommend that fixer, please post the formula here. Bear with me as I am only beginning to learn mixing my own chemicals. I really hope you could help me. Thanks. -- +Shakti V. Message posted via PhotoKB.com http://www.photokb.com/Uwe/Forums.as...kroom/200610/1 Most conventional fixer formulas can be converted to "rapid" fixer by replacing the Sodium Thiosulfate with Ammonium Thiosulfate in the correct amount. The simplest fixer formula is just the thiosulfate and Sodium Sulfide. 5 grams per liter of Sulfide is enough to protect the Thiosulfate but some additional will prevent staining by carried over developer, around 15 grams per liter. There two reasons for making a fixing bath acid: one is for the hardener, alum hardener works only when acid; the other reason is to prevent carried over developer from being active. If a plain water stop bath is used with a neutral or alkaline fixer it must be thorough enough to wash out the developer. However, if there is enough sulfite in the fixing bath it will prevent carried over developer from causing staining although it will continue to develop just a little. Fixing time for either film or paper depends partly on the nature of the emulsion and varies with any kind of fixer. Rapid fixer _at film strength_ fixes paper fairly quickly but the time varies from around 30 seconds for some types to over a minute for others. The only way to test for this is to fix samples for varying times and test them for residual silver halide. The standard tests are either a 1% solution of Sodium Sulfide or a 1:9 dilution of Kodak Rapid Selenium Toner. The toner test works only if the emulsion has been well washed. Instructions for making up the Sulfite test can be found in several Kodak publications but I am not sure its on Kodak's web site anywhere. The test solutions "tone" any residual halide just as they would image silver. If the prints or films are completely fixed the test solution will not produce a stain. Any yellow or brown stain indicates incomplete fixing. There is a lot of misunderstanding about wash times. Neither Sodium or Ammonium fixer has any advantage this way. In a normal acid fixer with white alum hardener washing times are extended because two conditions tend to bind the thiosulfate and the reaction products of fixing to the emulsion. One factor is the alum hardener. Alum tends to act like a mordant when in an acid environment binding the thiosulfate rather tightly to the emulsion. The other factor is pH. Photographic gelatin has a "natural" pH, or Isoelectric point, just on the acid side of neutral. When acid it tends to bind thiosulfate because of the electric charges of the atoms. When made neutral this binding force is eliminated and the gelatin tends to repel the Thiosulfate ions and also the Thiosulfate complexes that result from fixing. At neutral pH alum hardener still functions as a hardener. The electric charge binding can be eliminated by making the emulsion alkaline but the hardening action of the alum is destroyed. A plain Thiosulfate and Sulfite fixer is about neutral, additional alkali really is not necessary. Wash times for fixer which is neutral and has no alum hardener in it are about half those for hardening acid fixer. Note that thiosulfate is bound up in the support of fiber base paper by other forces, notably frictional forces. The nature of the fixing bath does not affect this a lot so fiber paper still needs long wash times compared to RC or film. The use of a neutral Sulfite wash aid, like Kodak Hypo Clearing Agent, will change the pH of film or paper to neutral and also has the property of displacing Thiosulfate ions and fixer reaction products by an ion-exchange function. When a sulfite wash aid is used wash times are considerably shortened even when an alkaline fixer is used. Film washes out in 5 minutes, double weight fiber paper in about 20 minutes. The wash aid will also dislodge some reaction products of incomplete fixing which otherwise do not wash out even in very extended washes. Ammonium fixing baths do have some Ammonia odor. The neutral fixers have less than acid fixers but it is still there. These fumes are NOT dangerous but may be irritating for some people. I don't know of a solution for this. Acid fixing baths of all types tend to evolve some Sulfur Dioxide gas, this is the "sharp" odor associated with fixing baths. It can be very irritating to some people and can set off Asthma, etc. Neutral or alkaline baths produce much less of this gas than acid baths. There are a number of ready mixed neutral or alkaline fixing baths on the market. They are used in color processing and are also sold separately. Some fixers are sold with the hardener in a separate container which can be added or left out at will. Kodak Rapid Liquid Fixer and Hardener comes this way. The hardener bottle also has additional acid in it. Without the hardener this fixer is still acid but less so and has less odor. To insure complete fixing a two bath system is recommended, especially for Sodium Thiosulfate fixer. One begins with two fresh fixing baths and fixes for half the time in each. The second bath remains relatively fresh and can complete the chain of reactions necessary to make all the unused Silver Halide in the emulsion soluble so it washes out. The capacity of a single fixing bath to do this is very limited, a two bath system has on the order of ten times the capacity of a single bath. BTW, because RC paper has a very thin emulsion it washes out completely in about 4 minutes even when using an acid hardening fixer. The use of a wash aid is not necessary. I hope this is helpful. -- --- Richard Knoppow Los Angeles, CA, USA |
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rapid, non-hardening alkaline fixer, questions on formulae
Just use Rapid Fixer with hardener. Forget all this nonsense.
Shakti V. via PhotoKB.com wrote: I've researched on two other fixer formula because F-24 is a slow fixer. I want a rapid fixer. Here are the formulae: Neutral rapid fixer ammonium thiosulfate (60% solution) 200ml sodium sulfite 15g sodium metabisulfite 5g water to make 1 liter + However, I've read that ammonium in fixer is not for open trays because of the ammonium fumes. ~ So, here is another formula, the TF-2 Alkaline Sodium Thiosulfate Fixer Distilled water 1000 ml Sodium Thiosulfate 250 g Sodium Sulfite (anhy) 15 g Sodium Metaborate 10 g TF-2 will wash out of negative and print materials more rapidly than will an acid fixer. In jackspcs.com, it was not indicated how long PRINTS should be fixed in this specific fixer (but it was indicated it should be washed for 30 minutes). My questions a 1. The resource for the neutral rapid fixer formula didn't indicate the length of time for fixing FB prints. How long should FB prints be fixed in neutral rapid fixer? 2. Which fixer (neutral rapid fixer, or TF-2 alkaline) would you recommend? 3. If TF-2, how many minutes does it take for FB prints to be fixed in this fixer? Someone told me it takes 10 minutes to fix prints with TF-2, but an online source stated it fixes films (3-5 minutes) and prints (no. of minutes not stated) faster than usual fixers; so I thought, if it fixes faster, then it should not be 10 minutes like a regular fixer. How long, really, does TF- 2 take to fix FB prints? 4. I assume that since ther is no alum in either formula, then these fixers are non-hardening fixers. Is my assumption right? 5. Would you know other rapid fixer formula/e that would work with FB prints? If you do, and if you recommend that fixer, please post the formula here. Bear with me as I am only beginning to learn mixing my own chemicals. I really hope you could help me. Thanks. -- +Shakti V. Message posted via PhotoKB.com http://www.photokb.com/Uwe/Forums.as...kroom/200610/1 |
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rapid, non-hardening alkaline fixer, questions on formulae
An alkaline rapid fixer will speed up your washing time by a
considerable amount. Our Silvergrain Clearfix Alkaline Fixer is an improvement on older alkaline fixers, as it has no precipitate and has an enhanced buffering system. This is a true rapid fixer based on ammonium thiosulphate. For more information please read the technical data sheet: http://www.digitaltruth.com/store/si...ixandwash.html --Jon Mided Digitaltruth Photo http://www.digitaltruth.com |
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rapid, non-hardening alkaline fixer, questions on formulae
"nailer" wrote in message news On Sun, 08 Oct 2006 21:25:17 GMT, "Richard Knoppow" wrote: ------------------------------ # # Most conventional fixer formulas can be converted to #"rapid" fixer by replacing the Sodium Thiosulfate with #Ammonium Thiosulfate in the correct amount. # The simplest fixer formula is just the thiosulfate and #Sodium Sulfide. 5 grams per liter of Sulfide is enough to #protect the Thiosulfate but some additional will prevent #staining by carried over developer, around 15 grams per #liter. $$$$$$$it pays to learn the difference between sulfites and sulfides. I know the difference, evidently you can't tell typing errors from actual mistakes. ------------------------------X # Ammonium fixing baths do have some Ammonia odor. The #neutral fixers have less than acid fixers but it is still #there. acid fixers have less of ammonia odour than neutral and alkaline. Pure chemistry. In acid solution ammonia tends to form ammonium ions (odourless). ----------------------------X my advice - just stick to plain thiosulfate/sulfiTe solutions. Modern materials do NOT need extra hardening. Use sulfite bath afterwards. Ammonium thiosulfate works faster than sodium equivalent, but smells. Isnt it smarter and safer to use sodium salts and extend fixing time by 50%? Cheaper too. The literature indicates that Ammonium Thiosulfate is less sensitive to accumulated Iodide ions than Sodium Thiosulfate. This may have an advantage in fixing film which usually has a large content of Silver Iodide. There may be little advantage for paper where there is less Silver Iodide although variable contrast emulsions are supposed to have quite a bit. There is probably little advantage except shorter fixing time for Ammonium thiosulfate in a two bath system. An advantage of neutral or alkaline Ammonium Thiosulfate fixer is that it does not bleach. Acid Ammonium fixer is a mild bleach for metallic silver and can cause problems where fixing time is carefully controlled. In fact, Kodak's recommendation for removing dichroic fog is acid rapid fixer with Citric acid (15 grams per liter of working solution) added. -- --- Richard Knoppow Los Angeles, CA, USA |
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rapid, non-hardening alkaline fixer, questions on formulae
In article 67764ee139b1e@uwe,
"Shakti V. via PhotoKB.com" u15922@uwe writes: Here are the formulae: Neutral rapid fixer (Details snipped.) FWIW, the formula you posted is Ryuji Suzuki's creation; its Web page is: http://wiki.silvergrain.org/wiki/index.php/Fixer I mention this because it's not clear if you got it from there or from some other source with less information. + However, I've read that ammonium in fixer is not for open trays because of the ammonium fumes. The extent of the ammonia odor varies from one formula to another; with some, it's pretty strong, but for others it's barely noticeable. I don't know about Suzuki's Neutral Rapid Fixer, since I've never used it. I have used a commercial variant, Silvergrain Clearfix Alkaline (http://www.digitaltruth.com/store/si...xandwash.html). It has a very subdued ammonia odor; however, it's not identical to the posted formula. The two might vary in the strength of their ammonia odors. So, here is another formula, the TF-2 Alkaline Sodium Thiosulfate Fixer Distilled water 1000 ml Sodium Thiosulfate 250 g Sodium Sulfite (anhy) 15 g Sodium Metaborate 10 g TF-2 will wash out of negative and print materials more rapidly than will an acid fixer. In jackspcs.com, it was not indicated how long PRINTS should be fixed in this specific fixer (but it was indicated it should be washed for 30 minutes). This formula is published in Anchell's _Darkroom Cookbook, 2nd Edition_ (formula #134). Anchell specifies a 10-minute fixing time for prints, so this doesn't qualify as a rapid fixer in my opinion. This isn't surprising, since rapid fixers are usually made using ammonium thiosulfate rather than sodium thiosulfate. FWIW, I've used the rapid variant of TF-2, known as TF-3. It's definitely got a strong ammonia odor. Despite this fact, I've used it in trays. It wasn't a pleasant experience, but it was actually less bothersome than acid fixers, which irritate my nasal passages although they don't have as strong an odor. A commercial variant of TF-3, known as TF-4, is available. I've never used TF-4, but it's supposed to have a less powerful odor. It's also pretty inexpensive. 2. Which fixer (neutral rapid fixer, or TF-2 alkaline) would you recommend? I've not used either of them. Personally, I hate sitting there fixing prints for 10 minutes, so I use rapid fixers now, especially for prints. In theory, it won't make any difference for the quality of your final prints, assuming you use the products correctly. Thus, it's really a question of personal preferences for things like your patience for long fixing time, your tolerance of ammonia odor, your sensitivity to the sulfur dioxide produced by acid fixers, etc. You may just need to try multiple products to figure some of these things out; one person's "overpowering ammonia odor" may be another person's "barely noticeable ammonia odor" -- and similarly for other factors. 4. I assume that since ther is no alum in either formula, then these fixers are non-hardening fixers. Is my assumption right? Correct. This shouldn't make much difference for most products. The emulsions of Efke films are reportedly rather delicate and can benefit from hardeners, but for most films and papers it shouldn't make much difference. 5. Would you know other rapid fixer formula/e that would work with FB prints? If you do, and if you recommend that fixer, please post the formula here. As I mentioned, I've used TF-3 (http://www.jackspcs.com/tf3.htm) with success, but it does have a strong ammonia odor. I've recently been using Silvergrain Clearfix. It's got a much more subdued ammonia odor than TF-3 but is almost as fast-acting. Its Web site has unusually clear and extensive instructions. On the downside, it's pricier than some products. I'm thinking of giving TF-4 a try for this reason. Bear with me as I am only beginning to learn mixing my own chemicals. I really hope you could help me. Thanks. I've mixed my own fixers from time to time, but for the most part, IMHO it's not worth the bother. Certain commercial products, such as TF-4 and Kodak's Flexicolor (C-41) fixer, are actually less expensive than anything you could mix up yourself, unless you find a good local source of the sodium or ammonium thiosulfate. (Flexicolor fixer, despire being marketed for color film, works fine with B&W film and paper, and has the advantage of being very inexpensive. I don't know the exact fixing time for B&W paper, though.) -- Rod Smith, http://www.rodsbooks.com Author of books on Linux, FreeBSD, and networking |
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rapid, non-hardening alkaline fixer, questions on formulae
Rod Smith wrote:
This formula is published in Anchell's _Darkroom Cookbook, 2nd Edition_ (formula #134). Anchell specifies a 10-minute fixing time for prints, so this doesn't qualify as a rapid fixer in my opinion. This isn't surprising, since rapid fixers are usually made using ammonium thiosulfate rather than sodium thiosulfate. ..... I've not used either of them. Personally, I hate sitting there fixing prints for 10 minutes, so I use rapid fixers now, especially for prints. I really doubt it takes anything like 10 minutes to fix paper in fresh sodium thiosulphate fixer. I just did a clearing test with a clip of Eastman 5302 film which has a bromide paper type emulsion. After a presoak in water of a few minutes, clearing time in fresh Kodak Fixer was 50 seconds. (I thought the film looked pretty clear after 40 seconds, but it nearly vanished at 50 seconds.) Peter. -- |
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rapid, non-hardening alkaline fixer, questions on formulae
I believe that fixing time for films in TF-2 (sodium thiosulfate based fixer)
is 3-5 minutes. For prints, though, it wasn't specified, although a lot of users say that, to be safe, fix for 5-10 minutes, depending on exhaustion. Clearing times(i.e., 50secs.) should be mulitplied twice or more preferably, thrice, for film fixing time. As for the neutral rapid fixer, yes, the source was wiki.silvergrain.org. I am perplexed why they didn't post any other details like fixing time for prints and films, and dilution. Still, no one has given me an answer. Since the formula has 200ml only of ammonium thiosulphate, while TF-3 has 800ml (dilution 1:4, fixing time 1minute for prints), would it be a good assumption to dilute neutral rapid fixer 1:1, and fix for 1-2 minutes? To everyone, Thanks for your replies. I am now at a phase of wanting to learn the science of mixing my own chemicals. It will also be practical for me as it's becoming a desert here when it comes to supplies for traditional photography. Shipping is more expensive than my energy and raw chemical cost. I am now working on the TF-3 formula. I will post a new thread regarding the process of mixing it and the results. Please post your comments and suggestions there. Grazie. I really doubt it takes anything like 10 minutes to fix paper in fresh sodium thiosulphate fixer. I just did a clearing test with a clip of Eastman 5302 film which has a bromide paper type emulsion. After a presoak in water of a few minutes, clearing time in fresh Kodak Fixer was 50 seconds. (I thought the film looked pretty clear after 40 seconds, but it nearly vanished at 50 seconds.) Peter. -- +Shakti V. Message posted via http://www.photokb.com |
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rapid, non-hardening alkaline fixer, questions on formulae
Films vary in clearing time, but I don't think
I'd fix any film for less than 3 minutes, let alone 50 seconds. It's generally recommended to fix _TWICE_ the clearing time for film...Prints (in rapid fix mixed film strength) can be fixed 30 to 60 seconds (FB.) Kodak actually says 5302 film should be fixed 2 TO _10_ minutes at 65 to 70 degrees F depending on the film/fix combo. Please see KODAK pub. E103CF.pdf Peter Irwin wrote: Rod Smith wrote: This formula is published in Anchell's _Darkroom Cookbook, 2nd Edition_ (formula #134). Anchell specifies a 10-minute fixing time for prints, so this doesn't qualify as a rapid fixer in my opinion. This isn't surprising, since rapid fixers are usually made using ammonium thiosulfate rather than sodium thiosulfate. .... I've not used either of them. Personally, I hate sitting there fixing prints for 10 minutes, so I use rapid fixers now, especially for prints. I really doubt it takes anything like 10 minutes to fix paper in fresh sodium thiosulphate fixer. I just did a clearing test with a clip of Eastman 5302 film which has a bromide paper type emulsion. After a presoak in water of a few minutes, clearing time in fresh Kodak Fixer was 50 seconds. (I thought the film looked pretty clear after 40 seconds, but it nearly vanished at 50 seconds.) Peter. -- |
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rapid, non-hardening alkaline fixer, questions on formulae
Tom Phillips wrote:
Films vary in clearing time, but I don't think I'd fix any film for less than 3 minutes, let alone 50 seconds. It's generally recommended to fix _TWICE_ the clearing time for film. I know. I just indicated that 5302 clears much faster than camera films, therefore should also probably have a shorter fixing time. Since 5302 resembles paper emulsion, I suspect that paper fixes in less than half the time required by typical camera films. ...Prints (in rapid fix mixed film strength) can be fixed 30 to 60 seconds (FB.) This also supports the idea that paper fixes faster than film. I find it hard to credit the idea that sodium hypo would be ten times slower than ammonium hypo unless it has been seriously overworked. People do overwork paper fixer because it is hard to tell by looking when the fixer starts to lose activity. If you use sodium hypo then a two bath fixer looks like a really good idea. I'd just be really surprised if two minutes in each bath weren't long enough. Peter. -- |
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