foot warmer for heating trays in darkroom

Last night I got frustrated with my wet printing because the trays got cold and kept making muddy prints. This is almost summer here but the AC makes all the cold air come down to the basement where my darkroom is. I have decided to invest in something to keep my trays warm. Besides a small space heater, I am considering a heated, waterproof blanket of some sort to put under the 11x14 trays.

Now, I am very aware of this great suggestion of the pig heater blanket in a APUG post:

(there was a url link here which no longer exists)

This blanket seems nice but is pricey.



As an alternative I came across these waterproof foot warmers on Amazon:

http://www.amazon.com/Indus-Tool-FWB-16-by-36-Inch-Foot-Warmer-Mat/dp/B0013V1PYA/ref=sr_1_16?ie=UTF8&qid=1337792212&sr=8-16



These are waterproof, sealed and the right size for me. Additionally these are much more reasonably priced than the pig warmers. I was wondering if any one else is using these for keeping their trays warm in darkroom. Do you think I can use these with dimmer switches to adjust the temperature? I don't want to add complexity of a submersible heater or even a thermostat. But I do have a waterproof digital kitchen thermometer that I can use to check the tray temp. once in a while. Any other thoughts?

Maybe turn off the ac or close a door.

You might also want to consider insulating the darkroom to prevent the cold air (and keep it upstairs where it belongs). The easiest product would be reflectix or the stuff from Dead Link Removed. I've used both. These are not messy like most insulation.

Your electric heaters might be allright, but I'd not trust my life to them underwater, even if you do have a GFCI outlet to plug it into. If a footwarmer gets compromised on the floor, the path to ground will be the floor not your body. One product I have used outdoors in wet conditions (melting groundfrost) is the powerblanket. It doesn't get super warm. It'd be great for keeping trays warm, but it's kinda expensive.

Sorry for not mentioning it before. My darkroom is in a bathroom which is already insulated.

Turning off the AC would be fine with me, but that might not go too well with the wifey especially because its hot upstairs where we sleep and I do my wet printing when everyone goes to sleep!

If your in the bathroom you can periodically change in warm or hot water into a double tray system, chemicals in a smaller tray, warm water in larger tray and stack the trays. Cheap, fast, and you will not electrocute yourself.

Also covering the trays when not immediately in use with an insulator may help.

kmallick said:

Last night I got frustrated with my wet printing because the trays got cold and kept making muddy prints.

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Are you sure cold trays are the problem? Could it be something else that is causing muddy prints? Fogged paper, exhausted dev, thin negs for starters?

There is a link on your Amazon site to Cozy Foot Warmers, 13"X20, rubber, 135f on the surface. For $46. That solves my problems right there.

Newt_on_Swings said:

Maybe turn off the ac

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I was going to suggest that.


Steve.

I've never experienced muddy prints from cold developer, only exhausted developer. Had fogged prints from bad safelight and old paper.

At work, we ordered a bunch of those foot warmers. They give off a burnt rubber smell. Maybe seedling warming mats will work?

cliveh said:

Are you sure cold trays are the problem? Could it be something else that is causing muddy prints? Fogged paper, exhausted dev, thin negs for starters?

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Developer (Ilford Multigrade) was mixed fresh just before printing. I opened a fresh pack of Ilford warmtone glossy 11x14s.

I got some nice keepers with excellent contrast after I warmed up the developer back to 70 F. But then it tapered off to producing the muddy ones. All 3 of the solutions, dev, stop and fix were quite cold to the touch.

I am going to give the 16 in. x 36 in. foot warmer a try. For $50 its worth a try. I will put it below all the 3 trays to keep the temp. around 70 F. I will report back on how it works.

I use a regular wet/dry heating pad under the developer tray in the winter, when I keep the house at 53F. I bought the pad at the drugstore for $12 or some such. It was the smallest lowest wattage pad I could find.

I put a towel under the heating pad to keep from warming the darkroom bench and another over the pad to limit the amount of heat getting to the tray.

The result works very well - the temperature stays constant even though there is no thermostat [which it should if the ambient temperature is constant].

I have two of these Kane pig warmers and you won't beat them with anything else. Set temp one time and they have kept it cosistently for several years.. They are almost indestructable.

eclarke said:

I have two of these Kane pig warmers and you won't beat them with anything else. Set temp one time and they have kept it cosistently for several years.. They are almost indestructable.

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I am tempted to get those Kane pig warmers as I have seen good feedback on APUG. However, I cannot see any difference between that and the foot warmer which is half the price!

How about a waterbed heater? I believe that they have some water protection built in.

If you do not wish to bother with more warmth try adding a bit of sodium carbonate to the developer (Try 5g per liter of working solution.) - David Lyga

Nicholas Lindan said:

I use a regular wet/dry heating pad under the developer tray in the winter, when I keep the house at 53F. I bought the pad at the drugstore for $12 or some such. It was the smallest lowest wattage pad I could find.

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This makes sense. Some come with adjustable levels of heat, you can find the setting that does the trick.

I have one of the long black footwarmers. But I use it for my feet. It does give off a rubber smell, but not noxious. I think if you used the long rubber heating pad you would need a way to switch it on and off regularly because it would probably get too hot. I wouldn't submerge it but it sounds like your trays are on a counter. You might want to cover it with a shower curtain or something to keep the chemical spills from staining the ribbed surface.

I am using a terrarium warming mat that is actually designed to keep reptilias cosy. Comes in different sizes, mine is about 30x100cm so I can fit the three trays (24x30cm) on it. Works quite nicely - in fact, I have to monitor the temp because it may rise close to 25°C (or to 30°C if the trays are covered with a lid), and switch it off/on when needed. Gives no smell, doesn't take loads of electricity, and is not afraid of liquids - makes it easy to clean, too. Solved all my temperature problems.