MacGyvering a tempering bath for color development

Is this what I need?

Hello, all...


Thanks for resuscitating this thread from the past!

I'd never look for it and would end up buying some very expensive "digitally controlled water bath"! Yes, I had that in mind and looked for it on lab equipment stores, which carry models as expensive as 300 USD (here in Brazil) for 6-liter capacity.

Now I am sourcing the PID sensor, temperature probe, SSR and everything else I need. I've found this:

http://www.aliexpress.com/item/free...282562396.html?spm=2114.31010208.0.332.DCVezm

For 15 USD, it comes with a sensor probe and a powerful 40A-rated relay, which should be good for up to roughly 5000W (with 120VAC input) heating elements... That would heat a lot more than 6 liters of water to 38 C, right?

Besides the heating element itself, wires, terminals (I like my work as tidy as I can), tools and a nice container, do I need anything else?


Cheers,
Flavio

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Try This:

http://www.amazon.com/Sansaire-Sous...words=Sansaire+Sous-Vide+Immersion+Circulator


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dpn said:

You'll need the actual probe that attaches to the thermocouple, and I'd highly recommend a small aquarium powerhead for circulation.

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Doh! I forgot the pump! This should be pretty easy to find and cheap.

dpn said:

For what it's worth, if I were starting from scratch, I'd seriously consider using an inexpensive roasting oven plugged into a PID.

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I am going the harder route. I like fiddling with this kind of stuff...

I am going to make the container and dip and dunk tanks out of 3mm thick PVC sheeting. The container will also have some kind of insulation... And it will still be a lot cheaper than the stuff I can buy here!

Thanks for the help. I'll be ordering those right away!


Cheers,
Flavio

Have you tested for continuity on that SSR? The light may be on, but that relay might not be closing.

How is your heater plugged in to the relay? Are both wires going to the relay?

Or is a hot wire going into one terminal on the relay, another wire going from other terminal to one end of the heater element, and then a wire from your neutral going to the other end of the element to complete the circuit?

That's your problem right there. The relay is just a switch. It doesn't power anything. The switch is flipped by the introduction of the DC current.

So your hot goes through it and is turned on and off by the relay which the PID controls.

Hot goes through your relay to your heater and is turned on and off by the relay. The neutral from your heater goes to your neutral.

Stay safe.

Buillt one yesterday evening, too. Yes, the wiring is somewhat ugly. Yours looks correct. I like the idea about a separate power supply for the PID module, this could simplify the wiring.

My immersion heater has a standard plug and I attached a socket to the SSR and wired the ground pin also. Not having to disassemble the heater and connecting all three pins contributes to safety IMHO.

Lars

Had great discussions about ground and safety myself as well on flickr. Well worth the read.

http://www.flickr.com/groups/ishootfilm/discuss/72157632985514766/

As long as the system is ground properly, you're safe. But you can always temper it in between processing if it makes you feel comfortable. Just flip your switch off when you're going to do a run. 5 - 10 minutes being turned off isn't going to make a difference. Temperature in the bath shouldn't drop.

dpn said:

Thanks for the link Wayne -- lots of good info there. I'm really paranoid now -- I don't know whether I'll be able to make it safe enough. I'm looking at alternative tempering bath solutions now.

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With the kettle and the thermometer i have mentioned you would not even face with these problem and could be out for shooting wonderful images since ages

To all aspiring MacGyvers out there: after a couple of years with my "Americanized" version of my water bath, I finally decided to upgrade to something commercial - an Anova Sous Vide Immersion Circulator. This system takes all the components I lovingly scrounged off the internet and packages them in a neat, clamp on commercial package. My measurements show that it is very accurate, and it is extremely easy to set up and use. It heats a water bath very quickly and holds the temperature well.

Instead of my large ice chest, I'm using a Cambro 12189CW135 Food Storage Box, with cover.

Total investment is much more than my original McGyver project, by nearly 10x. But this solution is far more "wife compatible", and we use it for actual sous vide cooking too (after a thorough cleaning of course).

I guess this is not quite as much of a sellout as going digital, but if you want to avoid the hassle of the MacGyver approach, a modern sous vide immersion circulator is a nice solution.

-chuck

ps: Don't throw out the black packing foam the device comes with. Use it to create a simple foam cover for the Anova's bright display. I used two layers of the foam, one of which is cut out to fit around the face, with the other backing that to form a wrap around cover. I taped the two layers together along the edges using black Gorilla tape. Totally light tight, took 5 minutes to make.

I use a arduino as a PID and a high power aquarium heater for my setup. Works good.

EdSawyer said:

This is basically a DIY version of the Phototherm Model 14 tempering bath unit, which show up on Ebay from time to time. Sometimes as low as $50 but more often a bit more. Another option for the non-DIY types. I used a Model 14 for a long time when doing RA4 in drums, before moving to a Fujimoto CP31/51

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Hi Ed - jumping into this thread because I have a new account and need 20 messages to PM people. Do you happen to still have either of these Fujimoto processors, and would you consider selling one?