advice for submersible heater

[jordanstarr]

being in a basement in Canada, it's hard to keep paper and film developer (8x10 tank) at room temperature...it's a very frustrating experience as I try to keep it consistent, the prints and film are not as consistent as I would like. Does anyone have any advice on a specific product? on eBay? something under $20? Thanks in advance.

 

[ChristopherCoy]

Aquarium heater?

 

[dpurdy]

http://www.ebay.com/itm/Titanium-He...258?pt=LH_DefaultDomain_0&hash=item2a22418b3a

Yes that is what I do in my cold basement. i have one similar to this in that the entire heating element is submersed and can lay flat while the controls are left out. I use an over sized tray under my developer tray and heat a water bath or sometimes I just put the heater into the developer. In both cases you have to rock the tray a lot to spread the heat.

 

[ozphoto]

Aquarium heater?

Was going to suggest the exact same thing. I remember my grandmother using one with her tropical fish (years ago!!), and it was a set temperature. Do they now come with an adjustable thermostat these days?

 

[MattKing]

This might help - and definitely has one of the best APUG thread titles ever: (there was a url link here which no longer exists)

 

[Dennis S]

Another good device for under trays or containers:
http://www.my-waterbed-shop.com/store/products26.html

 

[mandoloid]

Here in my Michigan basement winter temps give me the same problem. I have found that seedling heating mats from growing suppliers like Tek-Supply (sorry, no link now) are the cat's meow. Place them underneath your trays and you can hook them up to a thermostat or just plug them on and off as needed. The one I use will fit three 11x14 trays on it.

 

[Steve Smith]

being in a basement in Canada, it's hard to keep paper and film developer (8x10 tank) at room temperature.
.

I bet that it stays at exactly room temperature. The problem is your room is too cold!


Steve.

 

[BMbikerider]

For what they are, specialist dish heaters are very expensive. However in the past I made one that worked, but with no thermostat. All you need is a metal box (I used one that biscuits (cookies) came in around Christmas time. I cut a hole in the side and fitted a light socket to take a 15watt bulb. The cable to a power point was made using 3 core cable, two to the base of the light socket and the 3rd screwed to the side of the box as an earth return.
It did before I was able to afford a proper heater.

One other alternative I have considered in the past was a heated rubber mat such as those used by physiotherapists to apply heat to a patients back. They have a variable heat setting and are a lot cheaper than conventional dish heaters

 

[rbeech]

I use a "heating pad" directly under my developing tray. Works Perfect!

 

[bobwysiwyg]

I use a "heating pad" directly under my developing tray. Works Perfect!

Do these pads have thermostats? If so, reasonable accuracy??

 

[mandoloid]

Sounds like rbeech uses something like I do. It's like a 20"by 48" plastic place mat. I swiped it from my wife's gardening set up. I used to use a thermostat sans/temp- scale so I had to fidget around to find the correct setting. That said, it's easy enough w/out the thermostat. Watch the thermometers in your developing trays and just plug it in a minute or two every 15-20 mins. It depends on the temp of your room I guess. I've tried it underneath a water bath tray to smooth temp swings but found that not necessary (for me), even with 55 degree room temps.

 

[fotch]

I bet that it stays at exactly room temperature. The problem is your room is too cold!


Steve.

I think Steve is right. Maybe insulate your darkroom & use an electric heater to maintain a minimum temperature.

 

[Jon Shiu]

I just put an electric oil-filled radiator heater under the counter that holds the trays.

Jon

 

[jordanstarr]

thanks for the advice guys. Unfortunately I don't think matts would be the best option for me and in a 100 year old farmhouse basement, getting the room temperature up would cost me over $100 a month just in heat let alone drywall and insulating the brick walls -but I did toy with that idea in the beginning of setting it up. I was looking at submersible heaters for aquariums, but i was hard pressed to find one without lights on it or that would fit flat in a tank, but I guess I'll just have to look harder.

 

[Diapositivo]

Submersible heaters for aquariums don't reach the temperature required for colour processing (38 °C) because fishes would die. If you develop colour that means you'll have to "modify" your heater (break it so that the knob turns freely beyond the maximum temperature).

I think for your case the best is one of those food-warmers with a thermostat. I assume you only need one tray with really correct temperature. You will probably be able to find some in a second-hand store or used on the internet.

Something like this:

http://www.amazon.co.uk/SWAN-SW0200...r_1_4?s=kitchen&ie=UTF8&qid=1354991384&sr=1-4

make sure there is a thermostat.

No water, no light (or easily maskable) and no great expense either.

 

[bobwysiwyg]

Don't food warmers have too high a minimum temp? Seems like you would want to keep food temps pretty high to avoid health issues. :confused:

 

[mhofmeist]

You could use a water bath thermostat, as is done in the chemistry and molecular biology labs. They are expensive when bought new, but with some luck and patience you can get them used at very moderate prices (but not below 20$ ). The simple technical principle is always the same, but the lab thermostats are rather precise, in contrast to any home-built solutions like e.g. aquarium heaters, and far better built than the comparatively cheap ones you in former times could buy for amateur photo labs. Once you have calibrated the built-in thermostat, you can trust it, sometimes to a tenth of a grade. You can just put your chemistry bottles into the water bath, if they float, put some weights on them. There are special ring-formed weights (lead coated with plastic) available for this purpose from lab suppliers, but of course they are not cheap (almost no lab supplies are ). Either you make some yourself (rings from (stainless) steel or so) or again try to find used ones.
The bigger ones (heavy, not sooo cheap) of these machines can even be fitted with an external heating circuit, like a very small central heating. So you can heat almost anything (within certain size limits ) with it by connecting some tubing etc.
So you could put your tank into the water bath if heating the chemicals in their bottles before use is not enough, but there will be some splashing around, when you move it or take it out. Perhaps you can live with that. Or you wrap some suitable tubing very closely around your tank, basically building an outer jacket, and connect it to the "mini central heating" mentioned above. Then you can keep your bottles inside the reservoir which the bigger lab thermostats (with external circuit) invariably have. A double-walled developing tank would be great, but probably does not exist

 

[Bob-D659]

Try a battery blanket from Cdn Tire on your 8x10 tank. You can control the temp with a standard dimmer type wall switch.

 

[John Weinland]

I've tried a lot of heating ideas, and aquarium heaters work, but their thermostats are not very accurate. However, they are intended for submersion, and are rated and certified for that application. Black and white processes should not be too fussy about temperature. For fussier color processing (film development) I had to purchase a lab heater from Cole-Parmer for about $175. It is accurate, although a little fussy, and the least expensive reliable solution I could find. Be sure to observe all electrical-code regulations and safety procedures.

 

[canuhead]

I'd also look for used DevTec heaters. Looks basically like those bbq charcoal starters with the heating element but is submersible and has a thermostat and temperature control. It's designed for warm temps so it won't maintain do 20° c unless you cycle it. Used to use it for processing Tmax films at 100° F.

 

[Diapositivo]

Don't food warmers have too high a minimum temp? Seems like you would want to keep food temps pretty high to avoid health issues. :confused:

Your objection is sensible. One should look for one with a suitable temperature range. That should be fine for colour. For B&W I would just adjust development temperature, but I have no idea what temperature paper developer needs because I don't print. I gave for granted that colour paper needed high temperature but that might not be the case.

 

[mandoloid]

"Unfortunately I don't think mats would be the best option for me in a 100 year old farmhouse". I live in a 120 plus year old farmhouse with a cold basement and that is why I use the mats. Not to heat the room (which stays at 55F) but just the trays. Unfortunately, the 20x48" is more like $80, not $20.

 

[Bob-D659]

Insulating the basement would help lower the heating bills for the house. Plus you might find there is grant money available to help pay for it.

 

[Rafal Lukawiecki]

I use this in my sink to keep the water bath steady. Trays seem to hold within 0.5 C.