The Kodak guide is, I think, aimed at commercial darkrooms with multiple occupancy, and whilst very useful, the recommendations are a bit over the top for a domestic unit. We need a good fresh air supply and a ventilation system that will take any fumes away from us. One 6" extract fan will do this with capacity to spare in all but the largest room, provided it is on the other side of whatever nasties you are using, and your working position. The air inlet must be adequate, and preferably behind you. If you can arrange to pull your make-up air from the house, then heating, or cooling will not be a problem.
Originally Posted by DKT
Originally Posted by Dave Miller
Well, I thought the question was more to do with how to construct a local hood for an RA4 roller transport processor...if the processor is like a small fujimoto or something, then you might not need that. But, I gather since the majority of the machine is outside the main darkroom--that this is probably a 30-40 inch hope or kreonite. That's alot of nasty crap....
The RA 4 processor is a Hope 26" (measuring 36"x57"). It is a commercial style processor, meaning it has fairly large bathes. The darkroom will be held in the basement of a house where the owners have a small child.
In addition to the type of processor and environment, I am a binge printer. I spend 2-4 days, 12 hours a day every week to two weeks making prints. My initial plan was to print twice a month, mixing the chem's prior and dumping and cleaning the processor afterward. It is my hope that this will keep the bleach stink down to a minimum, allow the room to air out and to minimize the chance of algae, bad chemistry and a dirty machine.
My knowledge of ventilation is small. I have been doing a search for Ventilation: A Practical Guide. It seems very well regarded, but impossible to find. During the search I have learned a great deal more about ventilation. Most of the publications I have run across, assume a greater knowledge of HVAC then I presently have. The concentration toward being Practical appears to be what makes this book attractive.
I suspect, I can find the Kodak publication and see if it is applicable and understandable.
It also appears that I have put the cart in front of the horse. Opposed to organizing the room around drainage it should be built around the work flow (Enlarger -> print processor or dev trays - > wash -> dry) and to find a way for the drainage to be accommodating.
Currently I had planned on having the prints dry on screened racks. In addition to advice about ventilation, I am more than a little open to hearing how others dry their prints.
Last edited by mrcallow; 08-18-2004 at 10:15 AM. Click to view previous post history.
Reason: redundance removal
You have some very good advice already, though I haven't read all of the posts. I do have one suggestion re: the sinks. I can't tell from the drawing what size each of the four sinks are. However, it would be my opinion to put in one or two very LARGE sinks in addition to the wash sink. i.e. an 8' fiberglass or stainless sink. You could build one yourself (fiberglass) or have it mage locally by a metalworker (sheet metal/stainless).
In addition, a wash sink is good but you want a washer too.
"There is nothing worse than a sharp photograph of a fuzzy concept." - A. A.
The sinks will be 36"x48" ply wood reinforced and sealed with cloth and resin (fibreglass). The sinks are arranged as follows 1) dev; 2) stop;3)fix; 4) wash or Hypoclear. Following the sinks will be an acrylic archival wash which will hold the prints vertically in slots as the water 'snakes' through the baffles created by the slots.
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Originally Posted by mrcallow
Just looking at your diagram again--I think I might group the 2 processors together somehow. Maybe put a small 4 foot sink in between. This is sorta how our film darkroom is laid out. A sink in between the deeptank and the Wing Lynch. For one thing--you need clearance space around these processors to get at the sides & backs of the machines. You don't want to cram them into a corner that makes it impossible to service them for maintenance--AND--they'll need certain heights for drainage. Then, I guess it depends on what tank size you have in the WL, but you'll be mixing up gallons & gallons of color chemistry. A dedicated sink is really nice for this. The color stuff will be the worst. Having the processors in their own little area, might make it easier from a ventilation design--you might be able to isolate them somehow. You might also be able to gang them up on the same water panel--of course you couldn't use them at the same time probably. You'll need to have vac. breakers on the water line running into the processors--probably at the water panels, and check valves as well. This is for safety. I would make sure you have a free hose on a cold water line at all times for a makeshift eyewash--or get an eyewash or a portable one and put it in on the wall next to the processors.
the other thing is to rethink the batch processing. This will be time consuming(not to mention costly) to mix up fresh for a day and then dump. Those machines are better left with the chem loaded in them, than left dry. Then, each tank is probably--what?-how many gallons? Then, the repl. tanks. It would be better to establish some sort of routine where you can run the machine every other day or something. It's like money down the drain really--a machine is great when you need to print all day long or process film, but they're a money pit when they sit idle.
btw--if you lived in my area, I'd loan you these books--but I'm thinking you oughta be able to find them in a library or maybe get some similar info from an occupational safety agency--like your local labor dept. website--this is basically osha, niosh type stuff. Kodak had a great publication on commercial lab design year ago. "PhotoLab Design", pub. K-13 (here again, we have a copy or two in our library). It has scale drawings of lab layouts and all sorts of specs on their design and construction. Probably out of print now--but they have other tech publications as pdf's on this site:
kreonite might be another place to try for advice--at least on what it would take as far as installation for the hope. you might want to look into how much fix you can legally dump in your area as well....
just a thought--KT
DKT (et al)
Great advice. I will be revisiting this thread with a new layout implementing much of what has been suggested.
In the interim I need to pursue the ventilation, the available floor space and drainage options.
I also need to look into or see Bob Carnie about his drying racks. Having them in the darkroom would be a major plus. I have never liked curly prints and don't like the big drum driers either so I may start a thread or search for an existing one that covers that subject.