Kodak Kodafix

<p>I am getting ready to process my first B&W film in a long time and I have some questions concerning the fixing process. I bought Kodafix hardening fixer and it says to fix for twice the time it takes to clear the film. I don't know what it means to clear the film, or at least how to figure out that time. I have seen everything from 30 seconds to 10 minutes. Is it possible to "over fix"? Also am I to understand that you can reuse fixer and stop bath for a number of rolls. I have the kodak indicator stop bath but, some instructions say to dump it down the drain after use. I was under the impression you could keep using it until it lost its color? Also I am using Fuji Neopan 100SS to start with but will probably change film possibly to Acros 100 after these five rolls are gone.</p>

<p>The indicator stop bath turns purple when it is exhausted. The fixer can be used again. The fixer should have instructions for fixing times.</p>

<p>Yes, it does Jack, it says 5-10 minutes or twice the time it takes to clear the film. This is the problem, I don't know what they mean by "clear the film" or how to figure that time. </p>

<p>Fixing for twice the clearing time is easy to figure out. When the film first hits the fixer, it is literally not clear. It has a milky appearance and is more or less opaque. After the first 30 seconds or so in the fixing bath, it is also unaffected if exposed to light. So the next time you process a roll of film, go ahead and open the tank to inspect the film. You'll see exactly what I mean. The clearing time is the amount of time it takes for the milkiness to disappear. Twice the clearing time is double that. It is that simple. Things get a little more complicated if you consider that different films have different clearing times. The most often quoted example is the comparison between Kodak's TMax films vs. more conventional films like Plus-X and Tri-X. The TMax films can easily take twice as long, sometimes longer, to clear than more conventional formulations. Temperature and agitation are other variables that affect clearing time. Higher temps and more vigorous agitation can speed up to process. But don't let any of this worry you. It is practically impossible to overfix film. You'd need to leave the film in the fixer for hours before any noticeable image degradation occurs. A few extra minutes doesn't mean a thing.</p>

<p>Test your fixer for exhaustion with a clip test. Take a small piece of film and place 1 drop of fixer on it. Leave it for 30 seconds, then drop the piece into a vessel containing a sample of the fixer you wish to test. When you can no longer see where you placed the initial drop of fixer, the film is cleared and you have your baseline clearing time. As the fixer is used, the clearing time will increase. When the clearing time approaches twice the baseline time, the fixer is nearing exhaustion and should be discarded. For reasons mentioned earlier, please note that it is important to use the same type of film under similar conditions each time you test.</p>

<p>The yellow dye in an indicating stop bath is sensitive to the acidity of the stop bath. When the acidity decreases, the dye changes from yellow to violet. When that happens, the stop bath is exhausted and should be discarded.</p>

<p> </p>

<p>Thanks, that really helps. If I may, one more question, when you develop a roll, do you pour the chemical back in the same jug as the fresh chemicals?</p>

<p>Clearing time test.</p>

<p>Load the film in your tank. Before you start to develop take the leader that you cut off. As Frank wrote above, put a drop of fix on the <em>emulsion side </em>of the undeveloped leader; let it set for about 30 seconds. Drop the leader in a beaker or glass with a enough fix in it to cover the leader, say about an inch deep of fixer. Start your timer. When you can no longer distinguish the place on the leader where the drop was, the film is clear; you can literally see through it. Stop the timer. That is the clearing time.</p>

<p>Now start to develop your film. When you come to fix, fix for at least twice the clearing time.</p>

<p>The whole process sounds more complicated than it is.</p>

<p>The only critical time in the whole process is the time the film spends in the developer. A few extra minutes in the fix will not hurt; on the other hand under fixing is not good - either for film or prints. When in doubt, give it an extra few minutes in the fix.</p>

<p> </p>

<p>Don't worry about overfixing, within reasonable limits. I've tested negatives for up to a week in Ilford rapid fixer at normal dilution. Didn't destroy them.</p>

<p>Once rapid fixer is spent, it's pretty much gone. Extended fixing won't help. T-Max films will exhaust rapid fixer more quickly than most other films, possibly due to the iodide content. I usually get 10 rolls per liter of rapid fixer with T-Max films; up to double that with other films. If it takes longer than 10 minutes to clear, it'll probably never clear, a good sign it's time for a fresh batch.</p>

<p>I typically use three batches of rapid fixer: one for T-Max films; one for all other films; one for paper. I reuse all three until they're exhausted. I put strips of masking tape on the sides of the containers to check off each use.</p>

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<p> ...when you develop a roll, do you pour the chemical back in the same jug as the fresh chemicals?</p>

</blockquote>

<p>No, I do not. I usually mix up stock solutions of developers from powders in quantities of a gallon or 5L. Developers get stored in multiple, completely full bottles of which only one is in use at any given time. Fixer and stop bath are made up by the gallon and are stored in larger containers, since these are not terribly sensitive to oxidation. From these, I draw off only 1L at a time for use until exhausted.</p>

<p>Curtis,</p>

<p>I take it you are processing roll film, so I'll give you a simple, easy method. All the above responses are good. I'll try to give you a practical approach to get you going.</p>

<p>First, clearing time is as above: with the room lights on put a piece of the film )(the leader is good) you are about to develop into the fixer (you can put the drop on it as suggested above for more accuracy, but it is not necessary). Agitate and observe. Note the time it takes for the film to clear completely. Write this down somewhere, e.g., "Tri-x clearing time in fresh fix = 2 minutes 10 seconds." Err on the side of too long if there is any doubt. It is better to fix longer than underfix.</p>

<p>Now determine your fixing time by doubling the above time. In this case you would fix for 4 minutes, 20 seconds at least. I'd round up the time to the nearest minute for safety, so here, fix for 5 minutes. Sometimes you get very short fixing times compared to Kodak's recommendation. This is not wrong, but you can always fix for Kodak's minimum time without hurting anything.</p>

<p>Important: Note that you need to determine a new fixing time for every batch of film you process by using the clip test. You might get by with every other time, but since you have the film leader handy, it is easy and fairly quick to determine the correct time for every batch, so you might as well.</p>

<p>When done processing save the fixer you have been using in a separate bottle if it is not exhausted (see below). Don't pour it back in with the fresh stock. Next time you process, use the used fixer and find your starting fixing time by doing the good old clip test.</p>

<p>You must discard the fixer when the clearing time becomes to long. The rule of thumb is that the fixer is bad when the clearing time for a given film is double that in fresh fixer. In our example, you should toss the fix when the clearing time reaches (or approaches) 4 minutes 20 seconds. I'd toss it at 4 minutes just to be safe.</p>

<p>Your stop bath is good until it changes color. I keep a half gallon container and just pour the used stop back into the larger container when finished for the day. When the color starts to change, toss the whole bunch and mix new. Don't wait till it has become really dark purple, toss it at the first hint of bluishness.</p>

<p>Hope this helps get you going,</p>

<p>Doremus Scudder</p>

<p> </p>

<p>Kodafix is a convenient way to start. Later, you can save fixing and washing time by using a rapid fixer. Rapid fixers are of the ammonium thiosfulfate type and work faster than the sodium thiosulfate in non-rapid fixer. Also, rapid fixers don't contain hardener which is not an issue for most film. Some users of Efke film prefer hardening fixers because the emulsion is soft, but the few rolls of Efke I processed did just fine with Ilford rapid fixer.</p>

<p>Thanks a lot to all of you. My photoflex changing room showed up today so, the only thing holding me up is to finish a roll of film. Hell I'm tempted to go ahead and do the roll anyway with just 15 exposures but, need to learn to be patient I suppose. Here is something you may find funny, I bought a Paterson super system 4 tank with 2 reels from ebay, thinking that these were 35mm reels, I ordered another adjustable reel so that I could do my 120 film. As it turns out, I now have 3 adjustable reels for a tank that will only hold 2. Oh well, live and learn I quess. Glad it was only $9.00, some of my purchasing mistakes have been quite a bit more expensive.</p>

<p>Always good to have a spare reel in case one breaks. Good luck with your first roll of film.</p>

<p>Paterson makes 35mm-only reels? Heck, I just learned something new. I've only seen their adjustable reels.</p>

<p>What I like about the Patersons is they tend to remain flexible and relatively easy to adjust for many years. Very well made. Some of my older no-name plastic reels have become so stiff and brittle it's almost impossible to adjust them. Once adjusted to either 35mm or medium format I leave 'em as-is rather than risk breaking them.</p>

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<p>Paterson makes 35mm-only reels?</p>

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<p>Well Lex, apparently not. I misread the add for the tank when it said holds two 35mm reels or 1 120 reel. Maybe it should have said holds 2 reels adjusted for 35mm or 1 reel adjusted for 120 or something to that effect. The mind doesn't always comprehend what the eyes actually see.</p>

<p>When I develope film, I always develope it at the time per the instructions. Same with the fixer. I never bothered with "twice the clearing time" As long as the chemicals are not exhausted. There won't be any problems. I've been doing that since the early 70's.</p>

<p>I understand what you are saying Jack, and that makes perfect sense but, in this case the instructions are kind of vague. "Fix<em> most</em> films at 65-70deg F for 5-10 minutes or twice the clearing time" is exactly the instructions printed on the bottle. To someone with experience that might make sense but, even at 5-10 minutes it seems like a pretty broad range to me. Of course I did not know that "over fixing" was not a concern either. </p>

<p>As to the stop bath, those who save it until it is exhausted are probably correct. But since the dilution for the Kodak Indicator Stop Bath is something like 10ml into 20 ounces, I just dump it. I am afraid it will oxidize before I ever finish the bottle. Dave</p>

<p>I aways thought the stop bath was optional. I usually use water, even though I have some of the stop bath. Maybe the time for the fixer isn't as exact as for the developer. Maybe compromise and use 7 minutes.</p>

<p>Well, I ended up doing the clearing test, which determined 2 minutes, so I developed at 4 1/2 w/D76 @77 deg. 30 second stop bath and just to be safe on the fixer I doubled it then added I minute (5 min), which put it right in with what the bottle says, 5-10 minutes. Here are a few results:</p><div></div>

<p>And from the front:</p><div></div>

<p>One more: (a little dust in this one)</p><div></div>

<p>And finally,</p><div></div>

<p>I am goin to have to find a way to control the dust a little better. I live in the backwoods, on a gravel road, and there is no dust free place to dry negatives. And I haven't gotten used to this scanner enough to figure out how to do it with B&W. These were all taken with T70 and FDn 28 f/2.8 lens.</p>

<p>Couldn't notice any dust on my monitor, but if dust is an issue one strategy that might help is to take a room (such as a bathroom) and run some hot water long enough to raise the humidity a bit. Then as the mositure settles a good bit of the dust will settle out. This may or may not work well in the summer, though and it will take the film longer to dry in a humid room. I had read this a while back and thought it interesting. Another possibility is to get an aerosol plant sprayer and spray a fine mist of water into the air before hanging the negatives to dry. This might also settle the dust.</p>

<p>I am fortunete in that I don't have a dust problem here, but I have solved one in a previous house by building a drying cabinet. This was a scrap clothes locker (price = 'Just take the **** thing away') with a low wattage light bulb in the base to warm it up. This keeps the air moving and drys the film more quickly, which together seems to solve the problem. A friend made a similar cabinet out of a short length of large metal trunking.</p>