Here is a quick video, some pictures, and a parts list for my over engineered water bath. I will use this water bath for processing color film where maintaining temperature is critical for success. Of course, it could be used for processing B&W film too.
Note: This is by no means a detailed how-to/tutorial. It’s just a video, some pictures, and a list of parts that I used to make it. Hopefully it will give you some ideas for making your own water bath.
Video
Parts List
-Water Tank – I had my stainless steel tank already. You could search ebay for something that might work, or maybe you can find something at your local hardware.
–PID Temperature Controller, Thermocouple, SSR (Solid State Relay) – I didn’t use the Thermocouple (Temperature Sensor) that came with this kit. The thermocouple is not water tight. I could have sealed it up with a bunch of sealant, but that’s not my style. I purchased the liquid tight RTD sensor below instead. You may be able to find this PID for cheaper if you purchase just the PID without the Thermocouple. You’ll need to purchase the SSR (Solid State Relay) separately as well though, so it may be a wash.
–120 GPH Submersible Aquarium Pump – (Qty: 2) – The pumps circulate the water in the tank. You can probably get away with one pump, but I like two. It will depend on the size of your water bath tank too. The video shows only one pump.
–Liquid tight RTD sensor, 2 in, 1/4 NPT Thread (Deluxe Cable) – This is the sensor that monitors the temperature of the water in the tank.
–1000 Watt Heater Element
–Power Inlet
–Die Cast Aluminum Enclosure
–External Mount Heat Sink for 25A SSR
–Brass Pipe Fitting, Locknut, 1/4″
–Brass Pipe Fitting, Locknut, 1″
–Red 15A Single Round Outlet Receptacle – The red outlet is controlled by the PID controller and turns on/off based on the water temperature. It’s what I plug the heater element (yellow cord) into. You don’t have to use a red receptacle. I just thought it was cool.
–Hubbell AC Receptacle 15A/125 vac – (CNE) HBL5261D
–1 Gang Weatherproof Electrical Outlet Box
-2 A/C Neon Indicator Lights (1 Red, 1 Green)
-A/C On/Off Toggle Switch
-An old yellow extension cord I had laying around
-A power cord from an old computer to power the controller/system.
Pictures
Where did you get the stainless steel tub from for your water bath project?
Ron W
Hi Ron. Sorry for the long delay. Extremely long delay! I already had it. I would search ebay or Craig’s List for stainless steel tank, or sink, etc.
Love the way this looks! Followed you here from http://www.fumblingwithfilm.com post. Great work man. I would love make something like this. Is there a way to view your wire diagram?
Hi Geo. Sorry for taking so long to reply. Unfortunately I didn’t make a wiring diagram of the project. I should have. It was pretty basic wiring though.
Good looking setup. Where did you find the tank? It looks to be made of stainless steel.
Thanks Brian. You are correct, it’s stainless steel. I would search ebay or Craig’s List for stainless steel tank, or sink, etc.
Hi.
I have started to pickup info for building my own water controlled bath for C-41 (DIY is half the fun…).
Depending on the chimistry, C-41 needs 38°C +/- 0,5°C. There no place for approximation. What kind of precision can you get with your PID controller?
With your PID, do you control the “hysteresis” for better precision? Or is the auto-tune mode good enough to get this +/- 0,5°C precision ?
In other words, I just don’t know which PID controller tu buy. Are they all alike? Or should I watch for a model with auto-tuning?
Thanks for your input on this.
R.