Combi Plan dev tank teething problems : LUSENET : Large format photography : One Thread

I've just bought an HP Combi-plan T' tank to replace a stainless Nikor spiral tank which was scratching the 4x5 negs with occasional other problems.

I need to use inversion and have to use it in daylight mode, since I do not have a proper darkroom. I am only using it for B+W and currently am using DiXactol developer with Agfa APX100 film.

I have found a number of problems on first use, which hopefully experienced users will be able to offer advice, dodges or techniques to alleviate. Research led me to believe that the Combi--tank is the preferred dev tank for 4x5 and so either these problems are not significant, or more likely, I'm missing a few tricks and need more procatise!

1. Whilst loading film and placing film retaining clip on, I managed to get two sheets in one of the vee's preventing process fluids reaching top portion of one sheet. Also managed to get two sheets in one slot, despite trying to be careful and using fingers to locate sheet along loading guide.

2. Top valve is very stiff to rotate especially with wet fingers. If not closed fully, dev etc leaks out of vent.

3. It takes an inordinate amount of time to pour fluid in, 30 s or so I think. Clearly there is risk of uneven development and stop washes not being so effective. By applying breath pressure to funnel I was able to speed up drain process, but clearly have reservations about doing this on regular basis!

4. After the fix am I right that I can lift off lid to speed up wash water changes? If so, can I also do this for the staining stage of DiXactol developer?

Additional query, have just processed a 120 roll of APX400 which seems to have a much greater base fog. Or have I messed up on this too?!!!

-- Baxter Bradford (, January 20, 2002


I also use a Combi tank - looking at your questions ;

1. You do need to practice loading film to avoid such problems. Doing this in daylight with a few spare sheets will help you get it right in the dark.

2. First, you should probably be wearing gloves, especially if you are using a developer such as DiXactol, which uses similar chemistry to pyrogallol, and which can be absorbed through the skin with potentially harmful results. The stiff valve may just need a bit of time to loosen up, but as this on a large thread you may have a poorly made part which you may be able to return to the manufacturer for a replacement.

3. Breath pressure - !!! Please see above comments on safety using photographic chemicals. By doing this kind of thing, you run the risk of burning the sensitive skin in your mouth, poisoning yourself, and increasing the chances of splashing chemicals into your eyes.

In order to get the tank to drain efficiently, you need to loosen the top valve to allow air to replace the draining liquid. The tank should drain in 20 - 30 seconds.

4. You can remove the lid about halfway through the fix process, and keep it off thereafter. The post fix staining process can be done in daylight, as can the film wash.

-- fw (, January 20, 2002.

Persevere! There is a definite knack to loading the carrier - practice in daylight helps, but just take your time when loading. This may help though!! Here i the UK we have "Blu Tak" which is a putty-like material designed for holding posters to walls, etc. If you have a similar product then try "fixing" the carrier to the worksurface with a "blob" - you then have 2 hands free to guide the sheets in. I agree about the stifness of the top valve - took the skin off my fingers!! But it does loosen with use, and wearing gloves helps, so does a cloth. Filling the tank is also worrying - it takes such a long time, but I have found that by twisting the valve just past the tip of the arrow symbol on the lid allows the liquid to enter faster, also slightly tilting the tank whilst filling seems to speed things up. despite these drawbacks. I haven't found any signs of uneven development. Another trick is to lower the clip that holds the film in the carrier just enough the lock the sheets in, too far and the film pops out, too little and it escapes!! THIS IS WORTH PRACTICING IN DAYLIGHT, COUNT THE CLICKS (AS THE CLIP LOWERS) AND THIS HELPS WHEN LOADING IN THE DARK!!!! Oh yes, when inverting the tank do it gently and slowly, like you would do with 120/35mm but in slow motion, stops the film escaping!!! Sounds like a lot of hassle, but it does all fall into place and it is a good system for 5x4. Good luck Paul

-- paul owen (, January 20, 2002.

I eliminated this recurring problem of two negatives ending up in the same slot by using the slotted separator and clipping it into place after all of the negatives have been inserted. Without the separator and clip, agitation tends to dislodge the negatives resulting in the problem you encountered. To speed up outflow, I do just what Baxter describes. When he refers to loosening the threaded cap on the funnel on the upended tank, he means only part way, so that no light leakage occurs............................................

-- Quien No Sabe (, January 20, 2002.

Having two tanks eliminates the fill/drain time- this may not work for you if you can't achieve darkness during the process. At the start, I have the film loaded in one tank with the lid on, the other tank filled with developer and without the lid. When I am ready to start development, I turn off the lights and remove the film rack from the enclosed dry tank and place it in the developer tank while starting the timer. The lid goes on, then the room lights. About 15sec. before the end of development, the lights go off, I remove the film rack, and as the timer sounds, I place the rack into the original holding tank (which has been filled with stop bath). After the stop is complete, I use the normal fill/drain method for the fix as the timing is not as critical. I wash the film in the tank with no lid, water going in the top and out the bottom.

As for film loading errors, experience will cure these. Practice with old film in the light will help. It is very important to carefully check by feel that you have the films in their slots and not touching each other. It is best if you can limit yourself to 4 sheets at a time- more space between sheets.

Have faith, the Combi-plan has given me great negatives for years- even before I developed my two tank approach.

-- David Rose (, January 20, 2002.

I eliminated the problems you are experiencing when I chucked the tank and bought a Jobo 2500 Series tank and reel that can be inversion processed. There were too many problems with the HP tank including everything you mentioned, especially uneven development. Try processing a sheet of film that was exposed to a evenly lit gray seamless and see how the mottled appearance can ruin skys and other even areas in your image.

-- Jeffrey Scott (, January 20, 2002.

Hi, I also use the combi tank for a few weeks, I also have the same problems. Despite I'm loading the films very carefully, I already had two sheets in the same slot at the end of the process. I think we have to screw the system very tight until there is no bit of play on it, and we must process carefully by turning it over slowly. I use a piece of rag to rotate the top valve. I start to pour the fluid 30 sec before the end of the theoretic processing time, it takes 30sec more to fill the tank with the next fluid, but it doesn't matter in my experience. You see, I have no miraculous solution to give but if anybody got it, I will appreciate too! Regards

-- Daniel Luu Van Lang (, January 20, 2002.

I had one of these and got rid of it for similar reasons. Plus, I got surge marks around the top piece that keeps the film in the slots. Perhaps this last problem could have been solved through different agitation and making sure the tank was full. Anyway, I got rid of it.

-- neil poulsen (, January 20, 2002.

I agree with Jeffrey and Neil, get a Jobo drum either the 2500 series or the expert drums, a Beseler or unicolor base and you are good to go...

-- Jorge Gasteazoro (, January 20, 2002.

Thanks very much for the advice. I shall practise doing it with the lights on, get my blu-tack out and then when the lights go out.....wahaay!

Glad that it seems I'm not the only one to have experienced difficultirs and yes I too lost skin turning the valve!


-- Baxter Bradford (, January 20, 2002.


Here are the things I've found work best with the Combi Tank.

1) I can't figure out if you're using the slot guides when you load film. If you don't have them then you need to get some from HP Marketing. 2) The film has a tendency to dislodge during agitation if the retaining clip is on too tight. The clip should only slide down until it contacts the film. Otherwise the film is distorted and the chemical movement will push it into the next slot.

3) Because of the slow fill and drain the tank is best used with development times longer than 8 minutes. Agitate for the first minute after the tank is filled and then for ten seconds every minute after. I start the timer when I BEGIN to fill the tank and don't start to drain until after the timer has gone off.

4) To best avoid agitation marks face each sheet of film AWAY from the center spine. The spine will cause a linear mark if the inner sheets of film are facing towards it.

5) Wear gloves.

I've been using the tank for about four years and get very dependable results. Like every development technique you will need to refine your times to get your desired results.

Good Luck

-- Kevin (, January 20, 2002.

Hi, Please persevere, I have been using mine for about 6 months and I am very pleased with the consistant results. Yes you have to get to know it and I agree with Kenvin - we work in exactly the same way. Best regards Bob

-- Bob Ashford (, January 21, 2002.

Fill and drain from the bottom spout only. Use the spout that's on the lid as the vent only. Remove the cap on this vent when filling and draining for air passage. This way you will never have to loosen the vent at the threads.

-- Allan Fontanilla (, January 21, 2002.


About the film and retaining clip of the CombiPlan, I can only agree with the other answers that you find. Practice! Most of the procedures taking place in the dark are rehersed beforehand. Think of it as entering a new darkroom. I guess that you would like to get aquainted with it while the lights is on. (The same goes for most girls as well. :-)

Some people have reported problems with uneven developing in the CombiPlan. I guess that this has to do with the agitation pattern. It isn't a matter of turning the tank very quickly, rather to make sure that the developer "sits" when the tank is turned upside down. I also shake the tank in an irregular pattern now and then, as part of the agitation schedule.

The CombiPlan is very slow to drain/fill. Here's what I do:

I fill the tank with the 1 liter of developer needed and put it at its place. I then load the film in the holders and when I feel like I'm all done and I got my bearings, I dump the holder into the tank and then on with the lid. It is easy to time the time it takes from the dumping of the holder into the tank, through putting on the lid, putting on the light and starting the timer. That time should be subtracted from the total developing time. Of course this takes knowing exactly where everything is, i.e. practice again (and again...)

About 40 seconds before the end of the development time, I start to drain the developer. It is the stop bath (or possibly fixer bath for those who cannot afford the stop bath :-) that will stop the development, not draining the developer half a minute before. Besides, the developer is least effective in the end of the development.

Now, if you can subdue the light to a very low intensity, i.e. almost dark, you can lift half of the lid and pour on the stop bath directly. The same thing is recommended with the BTZS tubes, and it works the same here. There is no (or almost no) sensitivity left in the developed film. But please note that (Check www.darkroom- for the instructions for BTZS tubes.) The same of course goes for the following baths, i.e. fixer, hypo-clear etc.

When the film have gone into the fixer, you can turn up the lights, even if the lid is off. If you feel uncertain about this, keep the lid on for a minute. Then there is absolutely no way that the film will be damaged in any way.

For washing I normally have the bottom funnel open and have the water running just a little bit faster than the funnel lets out water, so that a little water runs over the top. I also dump the tank a couple of times.

I havn't done DiXactol, so I havn't a clue about the staining part. But I guess that light doesn't play a part in the staining, so it is probably OK doing it in an open tank with the lights on.

-- Björn Nilsson (, January 21, 2002.

A bit off the point, but a useful tip which was passed along to me and works quite well: once you get the hang of loading the film, you can cut plastic screening to the size of the film, and load 2 sheets, non-emulsion side of each against the piece of screen, into each of the slots. This allows you to process more than 6 sheets at a time (up to the limits imposed by proper amount of developer per sheet).

good luck! sharon

-- sharon gervasoni (, January 21, 2002.

"A bit off the point, but a useful tip which was passed along to me and works quite well: once you get the hang of loading the film, you can cut plastic screening to the size of the film, and load 2 sheets, non-emulsion side of each against the piece of screen, into each of the slots. This allows you to process more than 6 sheets at a time (up to the limits imposed by proper amount of developer per sheet). "

Two things.

1 Only do back to with black & white. This does not work for color. 2: The screening is not necessary. This is an idea used for teaching 45 processing at the Univ. of Montana and does make it easier for some to do back to back processing. It is usually done with fiberglass screening and not plastic or metal screening. Fine mesh window screen is best.

As to the comment about filling from the bottom. This can be a good way to cause streaks. The top is designed for the chemistry to fill from the edge of the tank when it is poured into the Light-Tight Hose Connector. The bottom does not have the flange to direct the chemistry flow.

Lastly this is an inversion agitation system designed to be used with a tank that is not 100% full of chemistry. It was designed for the chemistry to flow. That means invert and don't shake.

Of course, like any tank system, after filling it should be rapped to dislodge any air bubbles from the surface of the film. This is done by gently tapping it a couple of times on a table top after filling.

This is possible the oldest 45 daylight processing system made. Before we purchased the tooos from Gepe in the late 70s it was the Gepe Combi-Plan tank. Gepe purchsed the tools from the inventor of the system "Krause" who introduced it in the 30's or 40's in Europe. It is also sold as the Linhof System as they had distributed it in Germany for several decades

-- Bob Salomon (, January 21, 2002.

The chap I bought my tank from advised a larger funnel for quicker filling. I always use dilute development (20-30 mins) however which largely renders the point moot. I have had problems with marks at the top of negs and I now generously fill the tank with developer. Charlie

-- Charlie Skelton (, January 21, 2002.

Hello Baxter...

I use the Combi Plan and I like it more than any other system. Yes, in the begining I had the same problems as you do now but with practices they went away... all the above suggestions are excellent specially the the 2 tanks is how I do it... 1. for loading film, I use the guide and recheck like a blind person... 2. since I hate the slow filling (which wrecks my development time), I pour in advance the developer in the tank and leave it there. After loading the film I just dip the whole rack of film in the tank and close the lid and switch on the light, tap a lot (for bubles) and shake accordingly...when time is up I switch the light of, open the lid and empty the developer. 3. repeat the same for water rinse and fixing but it is not as critical as for developer, which mean you can use funnel as indicated by the manufacturer... hope this help....

-- dan n. (, January 21, 2002.

I hope this is not a double post. I posted a response that has not shown up so I'll try again.

I use the Combi system though not as recommended by the manufacturers.

1. I have one tank for each step; presoak, developer,stop,fixer, hypo clearing agent, wash, foto flo, and use it as a dip and dunk system. The funnels and top valves should not be used because the chemestry takes too long to fill, causing bubbles and streaks. By having a tank for each step, you can just lower the film holder in and out each tank.

Still, if you wish to use one tank, just have the succeeding chemestry ready and waiting to pour in with the lid off. Obviously this has to be done in total darkness. I do use the lids for each step so I can turn on the lights.

2. Loading the film takes a little practice. I do not double up but only process 6 sheets at a time. My systems came with plastic guides that are placed ontop of the film holders. Once the sheets are inplace, they are removed, and the holding clip put in place. Be careful not to press down too hard with the clip, but just far enough to touch the top of the film.

3. The agitation is very important. I invert the tanks with the axis through the wide part of the tank, so that the narrow part turns end over end. This way, the weight of the chemestry is on the edges of the film and not the flat part. This will keep the film from jumping the channels. Shaking can cause bubbles.

4. I have one tank with a rubber stopper that has two holes, inserted in the drain. This I use for washing, the water from top and out the bottom at an acceptable rate exchange.

I used to use trays but find using tanks gives far more even and consistent processing. As for Jobo, many noted pros swear by them and if you can afford one and all the tanks, gears, cups, etc, go ahead. But you will find you will have to get used to that system as well.

-- Rob Pietri (, January 21, 2002.

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