Darkroom Water Temp. Control
I am in the midst of setting up a small home darkroom in my unfinished basement, as you will see by my other posts.
I am doing this backwards, installing the wet side cabinets, sink, etc on the concrete side of the new room, then will work the dry side. There really is a reason for doing it this way, as I have to keep the size to the minimum useable space, and this gives me a better idea of layout and helps me to optimize the space as much as possible.
To date, I have the wet side basic plumbing done, the drain done, and GFI installed on the electrical. However, I still want to set up a temperature controlled line for the water besides the straight water lines.
To this end, I picked up a used Leedall 4629-M Photo thermometer, shut-off valve, and pressure release. It however, has a problem - it is missing its water mixing valve.
In a search, I found a brand new Leonard model 210 thermostatic mixing valve on Ebay for a very good price:
This will be used to feed the Leedall assembly. The only problem I can foresee that I might have is the Leonard temperature dial has a set screw to keep the previous temperature settings, but of course, this may turn out to be an advantage, if I find most of my needs are met by one temperature.
Filters will be used on the inlet hot and cold lines.
Can anyone see any great disadvantages of this combination? Fortunately, both the Leedall unit and the Leonard mixing valve are designed for 1/2" inlets and outlets.
It will be a bit of a Rube Goldberg device, but hopefully will work well enough for my purposes, and really kept the cost down to where it needs to be.
Any thoughts? Can anyone recommend a good water filter type. I assume it is chiefly a sediment filter one wants, but what model/brand?
Last edited by DavePEI; 11-18-2007 at 08:57 AM. Click to view previous post history.
My concern would be getting below the 2 litre/minute flow rate. That's a lot of water, I try to get my Powers panel down to about 250 ml/ minute if I can for print washing.
How about using a shower tap mixer ?
I use the filters from Calumet, the blue one for cold ater and the red one for hot water. I use the 5 micron filters. When you buy them, by several replacement O-rings which I replace annually. I would also buy several filters which I also replace annually (or perhaps more often if you are using the water all the time or have difficult water).
Originally Posted by DavePEI
Some suggestions for the water supply:
I like these things:
They are not cheap but having 3 or 4 distributed along the length of an 8 foot sink is very nice. You can put variable lengths of vinyl tubing on them for very convenient water use. Also, you can use quick-disconnect fittings for the vinyl tubing to swap out devices. For example, I leave my film washer out of the way to keep it clean and then just hook it up when I use it.
Some other thoughts: put shut off valves in both the hot and cold lines where the water supply enters the room, and then the hot and cold water filters so that you can easily change filters. Get a filter wrench so the work is easier. Write the date of last filter change on the outside of the cartidge. Consider having another outlet for water that does not depend on the mixing valve. If you have some type of problem with the valve, then you will have water access independent of the valve.
Also, think about making a stand for the print washer(s) outside of the sink, perhaps somewhat lower than a sink so that it is easier to insert and remove prints from the washer. A floor drain works good for that but might not be possible in a basement.
Pay attention to lighting over the sink. If the main light is behind you, then you will always cast a shadow on your work. That is true for safelights also. Perhaps some adjustable track lighting above the sink. It is nice to have some bright light for toning and bleaching prints or just cleaning up.
Also, make sure that you have enough GFCI electrical outlets near the sink for things like safelights, thermometers, tempering baths, Jobo, pumps, etc. E.g. I use a small electric aquarium pump to empty large tempering baths and need a place at the sink to plug it in.
Also, pay attention to above/below sink storage. Above sink storage is nice but might hang don too far or stick out to far for manipulating large prints or for your lighting, etc.
If I did it again, I would talk to a restaurant supply company about building me a custom stainless steel sink but that would be alot more than my 8 foot plastic sink.
regarding filters, I use the finest filtering household style I can get, and I use 1 filter on the outlet side of the mixing valve. I know you're only supposed to use these on cold water lines, but as a practical matter I never turn my mixing valve more than 25 or 30 c anyway, and I've never had a problem. I have municipal water that is high quality.
I think I will go only with the single filter on the output of the valve, but do like the idea (not the cost of filtering before the valve). The other option might be whole house filtration, but then that doesn't prevent lime and scale from the pipes from being passed through the system.
Thanks for your advice, all.
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Thanks for that info Jerold.