How to build deep tanks for LF?

Hello.

 

I was wondering if anyone had suggestions for how to build a deep

tank for film development that might be cheaper than buying a

stainless steel one used. I was thinking out of some sort of

plastic/plexiglass. Any tips on construction or materials?

 

Thanks

Sort of like a fish tank?

As long as it's cheap and won't react with chemistry. Sounds like a good idea.

Though they are cheap and they won't react to the chemistry (they are after all just glass, plastic and silicone adhesive,) a fish tank is not really a good idea, simply because you will need too much chemistry to fill one. Then you have the attendant problems of filling and draining the thing. Take it from someone who keeps fish - this is not a trivial exercise. Even the smallest 2.5 gallon fish tank can be a pain to empty, and you'll be hard pressed to fit anything larger than a few 4x5 sheets in it. If you are doing larger film, forget it - you'll need at least a 20 gallon tank to do that. Do you want to use that much chemistry to process a few sheets of film?

 

If you're doing 4x5 and really want to use a tank, I'd recommend the HP CombiPlan tank. It will hold 6 sheets of film, though they say you can put 12 sheets in back to back, and uses just a little over a quart of chemistry. Once loaded all the remaining steps are done in room light. You can get one from B&H for under $60. By the time you add up the cost of materials and your time, you're better off just buying the thing. Of course you can always process in trays.

Used 4X5 tanks are not that expensive. I wonder how much you can save making your own. How about Tupperware cereal keepers? And how will you hold the film?

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This might give you some ideas. He's using the Combi-Tank in a different way.

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href=http://www.largeformatphotography.info/alternative-developing/>http://www.largeformatphotography.info/alternative-developing/</a>

I second the HP CombiPlan tanks. Except that I have several - one for each chemical. I work with them open, in the dark and dip-and-dunk the film rack like the old stainless Kodak holders. Multiple tanks give me multiple racks, so I don't have to dry them to start another run. In fact, I can develop the second batch while still washing the first run.

 

If you persist in setting up a traditional 3-1/2 gallon deep tank line, I have just one thought: you need to design-in some sort of temperature control.

 

Unless your lab is carefully air-conditioned in summer and heated in winter, the chemistry temperature is going to vary with the room temp. And getting that much liquid cooled or heated five or ten degrees is no easy matter.

 

I tried this with Kodak hard rubber tanks many years ago in my basement lab. The winter ambient temperature is about 55 degrees, while it gets up to 80 in the summer. Since the hard rubber was a much better insulator than stainless, running hot or cold water down the outside of the tanks was nearly useless.

 

I had a friend in Aspen who kept an aquarium heater going around the clock in each tank. It almost worked, except in summer.

 

I still like the idea of HP tanks, even with having to make multiple runs. As a studio owner, it was the only peaceful and quiet time I ever got...

First of all, I should have mentioned it, I'm going to be doing 8x10. I planned on using the Kodak hangers and racks. Those will cost enough, I don't want to spend a whole lot on tanks.

 

As to temperature, I have a basement darkroom. The temperature is variable between 60 and 75 degrees, never goes out of that range. It never changes more than one degree during a development cycle, and I haven't found this to be a problem.

 

Thanks for the advice.

I had a sheet metal guy make up tanks to my specs. and he did lids (floating)

and caps also. Go to a machine shop or a sheet metal shop and see what

their fabrication prices are. You won't be sorry at all. I really like my SS tanks.

I did a bit of searching and came up with these. They are 3.5 gallon tanks designed for 8x10 films. Cheap enough at $35. Of course if you can get them made up for less, then it's no contest.

 

http://www.bhphotovideo.com/bh3.sph/FrameWork.class?FNC=ProductActivator__Aproductlist_html___13147___CETF810___REG___CatID=759___SID=F50E473A270

My tank for 4x5 negatives comes from a kitchen utensiles store. I paid 3$ for a set of 3 plastic containers of different sizes, with lids. One of the sizes is good to develop four negatives in holders. The other 2 containers I gave to my wife.

Since you're going to be using almost 15 gallons or more of chemsitry in a 3.5 gallon tankline, my advice would be figure out what your average amount of processed film will be in a month. Use 30 days more or less, since this is how long most tank chemistry will last with floating lids & covers--with a replenished dev. A 3.5 gal. tankline will run about 20 some odd 8x10 sized racks at a time, and you can usually average about 80, 8x10 sized films per gallon of chem. For the developers, this assumes that you replenish them properly. I usually do about 250 or so 4x5s per month in a 2 gallon sized tankline where I work...this uses 10 gallons of chemistry overall, including a tank with LFN in it. Each tank is s.s. and is 11"x11"x4.5". You could do 7, 8x10s in one of these tanks, maybe one or two more without the basket. I have seen tanks as small as 4 racks for 8x10 as well--they held about a gallon of chemistry and were very slender. So, my advice would be to design the tanks around the amount of film you'll be running daily, or however often you process. The best way to set them up is in a larger tank that acts as the water-jacket. These can usually be plumbed for use outside of a sink, or used in the sink. Or you can put the tanks in a sink and use a standpipe to run a water-jacket. When you do the water-jacket, it helps to jack up the temp so you don't have to wait all day...then taper it back down to processing temp. I find I can do a run with the water dumped and have it only drop maybe a half degree by the end--no sense in wasting water if you don't have to. As for getting the chem in & out? It's not like you do it every day....other than getting the fix out to a recovery unit, you pretty much dump the tanks down the drain. Once a month, I clean the bromide scuz out of the dev tank etc and then remix. It only takes an hour or two. Using tanks this size as a one-shot process is sorta like pouring money down the drain, so look at how much film you would run on average--not the busiest day, because you can always do multiple runs, but just the average day...my average day is maybe 20-40 sheets 4x5. We've shot as much as 75+ in a day though, so I'll do maybe 4 runs back to back on a busy day. Sure it's a PIA, but better than having all that chem going to waste. hope this helps.

Jason, I was in the same boat with developing my 8X10's when I started. I purchased used 3 1/2 gallon tanks and went that route at first. At first, just having 8X10 negatives developed was really the thing I wanted. I "plunged" the hangers in HC110 and D76 and was pleased with the 80 square inches of negative area. But, about a years after that, I started developing ONE sheet at a time in a deep tray (actually a plastic dishpan tub thingy I bought at a dollar store) and started exploring E V E R Y developer I could find. That was the trick for me! I discovered that as I grew as a 8X10 guy, I was shooting less and focusing on the afterexposure, and the negatives I produced went from "just big" to "well DONE" I eventually settled on one of the PRYO formulas (after having tried pretty much ALL of them) I use either WD2D, PMK, or PRYO Triethanolamine. (the latter I highly recommend as it is a non-staining pyro developer that is also EXCELLENT for 35mm and med format as well. It's available at Photographer's Formulary and VERY economical) USE the tank now, but be prepared to change someday. This is very true when you consider contrast control, ONE sheet at a time is tedious and slow, but it goes a long way toward learning the craft of controling contrast in -N, N, +N negative control

 

Dave