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#1
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question about fixing hp5
hello,
to fix a roll of hp5, the ilford data-sheet on their website says that i should use a 1+4 dilution of ilford rapid fixer, but i have a 1+9 dilution already mixed up; i'm wondering if i could just double the fixing time and use the 1+9 instead of the 1+4 (as the 'strength' of the 1+9 should be half that of the 1+4). would that work? any help is greatly appreciated. thanks, {pd} |
#2
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question about fixing hp5
hi
i fix my film for 7-8 mins then wash for 5 mins the thing with fixing film is you can not over fix and if you under fix and the film does not look right you just put it back in and fix for longer intill its clear. jeff b wrote in message ups.com... hello, to fix a roll of hp5, the ilford data-sheet on their website says that i should use a 1+4 dilution of ilford rapid fixer, but i have a 1+9 dilution already mixed up; i'm wondering if i could just double the fixing time and use the 1+9 instead of the 1+4 (as the 'strength' of the 1+9 should be half that of the 1+4). would that work? any help is greatly appreciated. thanks, {pd} |
#3
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question about fixing hp5
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#4
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question about fixing hp5
wrote in message ups.com... hello, to fix a roll of hp5, the ilford data-sheet on their website says that i should use a 1+4 dilution of ilford rapid fixer, but i have a 1+9 dilution already mixed up; i'm wondering if i could just double the fixing time and use the 1+9 instead of the 1+4 (as the 'strength' of the 1+9 should be half that of the 1+4). would that work? any help is greatly appreciated. thanks, {pd} Check the clearing time, that is the time it takes the film to be visually clear, and double it. Fixing time should approximate the time for Sodium Thiosulfate fixer. -- --- Richard Knoppow Los Angeles, CA, USA |
#5
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question about fixing hp5
RE
... i'm wondering if i could just double the fixing time and use the 1+9 instead of the 1+4 (as the 'strength' of the 1+9 should be half that of the 1+4). would that work? If that were the case a 1:24 dilution, 1/5 film strength, would take 40 minutes; allowing for 8 minutes at 1:4. Such is not the case. I expect 8 to 10 minutes at 1:24. Exceptional films might take a little less or more. Conditions: 20ml of fresh A. Thio. concentrate in a solution volume of 500ml; agitation 1st minute continuous and 15 seconds each there after. One-shot use. Dan |
#6
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question about fixing hp5
wrote in message ps.com... RE ... i'm wondering if i could just double the fixing time and use the 1+9 instead of the 1+4 (as the 'strength' of the 1+9 should be half that of the 1+4). would that work? If that were the case a 1:24 dilution, 1/5 film strength, would take 40 minutes; allowing for 8 minutes at 1:4. Such is not the case. I expect 8 to 10 minutes at 1:24. Exceptional films might take a little less or more. Conditions: 20ml of fresh A. Thio. concentrate in a solution volume of 500ml; agitation 1st minute continuous and 15 seconds each there after. One-shot use. Dan A lot of chemical processes are not linear, for instance, developer diluted to half strength does not take twice the time to develop. However, the danger with highly diluted fixer is that there may not be enough free thiosulfate ions to complete the fixing process. The only way to tell is to test for residual silver. The simplest test is to use a dilute solution of Sodium Sulfide. Kodak also used to recmmend Kodak Rapid Selenium Toner diluted 1 part to 9 parts water. However, this test will fail unless the film or paper is well washed. Completely fixed film or paper should not show any detectable stain from either test. A clearing time test is useful for checking the condition of a fixing bath. The old rule of thumb is that it takes about double the clearing time for complete fixing. This assumes the fixer is fresh enough to complete the fixing process, which is progressive. If its not the emulsion will not fix out completely in any length of time. Clearing time tests should be done with a sample of the film being fixed. The film should be soaked in water for a few minutes since wetted emulsion fixes at a different rate than dry film. For archival purposes a two bath system is strongly recommended. Its also more economical because the capacity is from 4 to 10 times that of a single bath. The use of a Sulfite wash aid will also increase effective capacity because it releases some partially fixed halide which would otherwise remain tightly bound to the emulsion. -- --- Richard Knoppow Los Angeles, CA, USA |
#7
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question about fixing hp5
Richard Knoppow wrote:
A lot of chemical processes are not linear... I suppose data from the sulfide and clearing tests could both be used to graph fixing time vs concentration. By contrast a fixer at 1:4 is a heavy syrup while one at 1:24 is a light. With normal use a fixer becomes loaded with the halides and the thiosulfate loads with silver. The syrup becomes heavier. Available free thiosulfate levels decline and fixing times lengthen. I'd expect a more concentrated Fresh fix to be quicker than a more dilute Fresh fix though a graph of concentration vs time would reveal some very interesting information. Using the same fix in the same tray or tank for sheet after sheet or roll after roll is, in my mind, A method of use. If that were the only method for film developers there would be no one-shot use of Rodinal, HC-110, Xtol, Beutler's, FX-1 or 2, and on and on, all often used as one-shot film developers. Besides, what other very practical way to practice single tray processing? One shot metered chemistry makes single tray processing a gas. No loading of the fixer means skip the stop. Also, the very dilute fix insures archival silver levels with one fix. DEVELOP, FIX, HCA, all in one tray. Make BIG prints in a small darkroom. Dan |
#9
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question about fixing hp5
Sorry meant hypo check.
darkroommike wrote: This is not too bad but hypo fix will only tell you when the fixer has failed not when it is almost ready to fail. The two bath method makes this a bit safer but to be safer still just tally the number of rolls you put through the fix. I used 100 rolls per gallon or 25 rolls per liter, then replace Fix 1 with Fix 2 and mix a new Fix 2--if you are using TMax films, make TWO tally marks for each foll of TMax you put through your fixer. Note that with the reduced number of films I now process I use a Unicolor Drum and use paper strength fixer one shot. You can also test the films you just processed (on a leader or blank frame removed from the rest of the roll, please!) using a hypo test solution like Kodak HT-1 to make sure you are getting proper fixation. The secret? that there is more than one methodology that will produce great results, you just need to find a method that works for you based on your circumstances and apply it consistently. i.e number of rolls you process per month, type of film you use, equipment on hand or cheaply available (I bought a spare Unidrum for US$5 at a swap meet not long ago and already have a spare motor base), etc. Mike wrote: I use the two fix method for black and white film. I keep checking on my first bottle to be sure I pull it when the fixer exhausts, use hypo check. The second fixer then becomes the first and I make up a new second bottle of 1:4. I put the film in both for 2 minutes each or 4 minutes total. Richard Knoppow wrote: wrote in message ps.com... RE ... i'm wondering if i could just double the fixing time and use the 1+9 instead of the 1+4 (as the 'strength' of the 1+9 should be half that of the 1+4). would that work? If that were the case a 1:24 dilution, 1/5 film strength, would take 40 minutes; allowing for 8 minutes at 1:4. Such is not the case. I expect 8 to 10 minutes at 1:24. Exceptional films might take a little less or more. Conditions: 20ml of fresh A. Thio. concentrate in a solution volume of 500ml; agitation 1st minute continuous and 15 seconds each there after. One-shot use. Dan A lot of chemical processes are not linear, for instance, developer diluted to half strength does not take twice the time to develop. However, the danger with highly diluted fixer is that there may not be enough free thiosulfate ions to complete the fixing process. The only way to tell is to test for residual silver. The simplest test is to use a dilute solution of Sodium Sulfide. Kodak also used to recmmend Kodak Rapid Selenium Toner diluted 1 part to 9 parts water. However, this test will fail unless the film or paper is well washed. Completely fixed film or paper should not show any detectable stain from either test. A clearing time test is useful for checking the condition of a fixing bath. The old rule of thumb is that it takes about double the clearing time for complete fixing. This assumes the fixer is fresh enough to complete the fixing process, which is progressive. If its not the emulsion will not fix out completely in any length of time. Clearing time tests should be done with a sample of the film being fixed. The film should be soaked in water for a few minutes since wetted emulsion fixes at a different rate than dry film. For archival purposes a two bath system is strongly recommended. Its also more economical because the capacity is from 4 to 10 times that of a single bath. The use of a Sulfite wash aid will also increase effective capacity because it releases some partially fixed halide which would otherwise remain tightly bound to the emulsion. -- --- Richard Knoppow Los Angeles, CA, USA |
#10
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question about fixing hp5
darkroommike wrote:
Sorry meant hypo check. HT-1 is a hypo check. So is HT-2. The two are used to check for thorough washing out of the hypo. You have in mind FT-1 which is the iodide test of the Fixer. ST-1 is a test for silver left in the emulsion. Use ST-1 along with FT-1 to be more sure of complete fixing. Dan |
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