HP CombiPlan question

[seawolf66]

it only takes 36 oz's to cover the film in combi tank and not have to worry if you got enough in it ! But would recommend you get some used 4x5 film and play with it in the light so as to be able to do it in the Dark : good luck and have fun:

[Nick Kanellos]

I've been using my Combi-Plan for 10 years. It's the only way I process my 4x5 negs. Contrary to some opinions expressed here, the chemistry does not drip down from the fill hole in the lid. It is channeled along the lip of the tank to 4 separate holes (one on each wall) from which it runs down the inside walls of the tank. The film comes in contact with the developer from the bottom up - evenly. It is the equivalent of slowly emersing the film in the developer. It takes about 30 - 40 secs to fill or drain the tank but I've seen no ill effects because of that. I select my developer concentrations to ensure my developing time is never less than 10 minutes - just to be safe. If you are worried, you can also pre-wet your negs.

In the 10 years I've had it, I've had a film come loose inside the tank once or twice. To avoid (or lessen) that possibility, I agitate by rotating the tank along it's narrow edge as opposed to front to back. This keeps any forces due to swishing liquid on the face of the film to a minimum.

Hope this helps.

[gevalia]

I'm going to weigh in here on the Combi Plan tank - from a customers point not a manufacturers pount of view. These views are my own.

I've been using mine here for a year give or take. Twice a week or more. For the 1st few months it leaked like crazy from the sides of the top (yes, washers were in). And it was very difficult to load the developer in a timely manner. 45 seconds to load all developer was frequent.

That being said, I am happy with it now. The leaking has all but stopped. I believe this is due to the rubber top becoming more pliable with age. Over the past 6 months it has gradually leaked less and less to the point where I would say it leaks about as much as a 120 stainless steel tank which is not much at all. As for loading developer, the issue (and I will stand by this) is one of vaccuum. As you pour in liquid, it replaces the air in the tank and that air needs to escape. You can actually hear the air whistling as it escapes which at a certain point it stops doing. And that point is when it starts to load slower and slower. My fool-proof way of loading liquid (15 seconds max) is this:
1. Assumes you already have the funnel on and that the valve (screw) is open as much as the documentation says).
2. As you pour into the funnel, take your thumb (of the hand holding the tank) and press it firmly against the funnel base where it hits the valve. This lets air escape as the liquid is poured in and will not cause a light leak.

I suggest trying this with water a few times 1st. Listen for the air coming out and you will be able to determine how much pressure you will need to put on the valve.

I want to say that I was extremely frustrated in the beginning with this tank. I have no space for a darkroom and have been using 120 SS tanks for a while. I ruined more then a few sheets because it too so darned long to load the developer. Gee, let's factor in a 45 second load time on a 7 minute development time. I was more worried about the pyro that was leaking all over my arms when I agitated. The mfg claim that the design has not changed is one thing but I'll put $$ on the thought that the materials used to make it have. As an engineer, nothing frustrates me more than a company that will not better a product when its customers report issues with it.

[gevalia]

[QUOTE=Nick Kanellos;427389]In the 10 years I've had it, I've had a film come loose inside the tank once or twice. To avoid (or lessen) that possibility, I agitate by rotating the tank along it's narrow edge as opposed to front to back. This keeps any forces due to swishing liquid on the face of the film to a minimum.QUOTE]

Nicks point here is a good one. I have had 2 occassions where a sheet has popped off the track and in both cases it was when I was agitating front to back(along the wide side). Now 2 out of a few hundred is not much but I have not had this problem since I shifted to agitating the way Nick describes.

[Bob Salomon]

The mfg claim that the design has not changed is one thing but I'll put $$ on the thought that the materials used to make it have. As an engineer, nothing frustrates me more than a company that will not better a product when its customers report issues with it.

Then you would lose the bet. The molds were made for the materials that were available when Herr Krause originally designed the tank. The molds require that original material that only BASF makes.

As for your leaking issue. We replace tanks that leak. There should be none at all! Simply send us your tank.

We also have never had anyone report a whistle while filling the tank. Again let us look at your tank to see why.

[Chuck P.]

I use three combi-plan tanks when I develop my film, not in the dip-n-dunk method as described in the article I've seen on the LF home page, too much uneven development with that method for me.

I go dark after the pre-wash, remove the film from the tank used for the pre-wash, insert it in the tank with the developer, install the lid, turn on the lights and start my development.

Go dark again with one minute left in development, remove the the lid gently to avoid sloshing the developer, pull the film from the developer with 10 sec left to let it drain and then insert it in the tank with the stop bath, stay dark for the agitation in stop bath (raise and alternating tilts for about 30-45 sec) and the few seconds it takes to transfer the film to the tank with the fixer.

Install the fixer lid, turn on the lights, finsih the process in daylight. Works like a charm. The only time I use the funnel is when putting water in the pre-wash tank.

I love the Combi-plan tank, leak issues were greatly reduced by shaving the small pieces of plastic remaining on the top edges of the tank from being in the mold so the lid would seat more cleanly. Also, I don't know if this helps, but I mark my lids and tanks with "D", "S", "F" so that the developer lid always gets used with the developer tank, etc...

[Steve_Renwick]

Dang. The Thread That Wouldn't Die.

[ki6mf]

I have 3 of them and have no problems. Pour Time is not a problem provided you are consistent. I like the lower side drain as it lets you wash properly. If you haul them around make sure the lower drain is removed as it can crack off if tossed around.

Usually leaks are a result of not tightening the drains properly. I do open the top and bottom when pouring to help speed up the pour time. If you forget to tighten them you will get leaks. Operator Error every time!