Tray heaters anyone? Or how to hot lith.

[Robert Hall]

I have been looking for years for a decent tray heater. I bought one years ago from Nova. The guy told me it was the last one and it was 220v. I was lucky because I have 220 for my light sources in my darkroom but it was also about $200. ( yeah, back when I was more easily parted with my money ).

Well, I seem to be the Salt Lake City repository for old darkroom stuff and a batch came my way the other day with what I thought was a tray warmer. it was older than I am, that's pretty old, and gave it a try. it heated to 125f and did a great job of heating my developer for doing hot lith prints.

I started doing a web search and found that submersible heating pads only turned up junk for turtles, not what I was looking for. Then I looked closely at the pad I was given and found it was a mat. It's a heated floor mat for standing on cold cement floors.

Now this was hardly submersible, but boy, did it do a great job of heating my soup. Now... forewarning: In no way did this say it was submersible, but one claim said it was waterproof. So if somehow you end up electrocuting yourself, don't blame me. I do stupid things all the time.

So consider this link a suggestion: http://goo.gl/j8H3b

Anyone else thought of this or a better solution for our solution?

[Andrew Moxom]

There were some threads opened on this a few years ago....http://www.farmtek.com/farm/supplies...;pg106120.html I wouldn't use these actually in your tray, but underneath would work well. they can be thermostatically controlled so that you can heat the trays from the outside and keep your lith developer at the right temperature.

[Bob Carnie]

I bought one of those pig warmers, I could not get it to give me adjustable temps and abandoned the idea. Murray M came up with the original post on this one.

There were some threads opened on this a few years ago....http://www.farmtek.com/farm/supplies...;pg106120.html I wouldn't use these actually in your tray, but underneath would work well. they can be thermostatically controlled so that you can heat the trays from the outside and keep your lith developer at the right temperature.

[Robert Hall]

Thanks Andrew, I remember these now. I don't see a stock item or price on them however. Do you think they are no longer available?

Have you used them?

[Robert Hall]

Thanks Bob,

Good to know. I can tell you I sure like this mat I found. At least so far.

I hope things are well your way.

[Robert Hall]

I bought one of those pig warmers, I could not get it to give me adjustable temps and abandoned the idea. Murray M came up with the original post on this one.

This, btw Bob, would work with a light dimmer switch. Man... I'm brilliant today!

[canuhead]

Depending on what temperatures you're trying to reach, I used to use a heater that basically looked like a long U that was submersible and had an adjustable thermostat. It had a minimum temp so I didn't use it much but it was great for heating Tmax dev to 100° for processing 3200 T Max. Will probably use it this winter to help keep my water bath at a steady temperature while printing. Can look it up later when I get home.

[Mike Wilde]

I use a wierd combo when I need a hot tray. Made this up doing c-41 8x10 negs re-shooting a dupe of a collage of hundreds of small photos using a process camera.

No film holder for that camera, just a vaccuum back holder, so setting it up to work in total darkness was actually the bigger part of the problem with the project.

The tray was a food service stainless tray. It sat on top of a water bed heater. The temp sensor for that heater sat with a bag of ice on top of it to make it run to hotter than normal.

The heater sat on top of a piece of drywall to even the heat out. The foam pad to drive the heat up sat on the drywall. The drywall was cut away in places like where the power cord connectd to allow the pad to lay flat under the tray. Definitely flaky, but the end result was satisfactory for that project.

Since then I have removed the bed thermostat and occasionally put such a heater in my darkroom sink, but then laid a heavy plastic liner in the sink, since this heater is not rated for immersion. thus, filled to 2" with water works great for getting all trays to the same temp, but is a pain to take down; you have to bail the water bath since the sink drain is covered.

It is most handy when I have a backlog of 4x5 e-6's to process. My tanks are hard rubber, and without thier own water jacket. I keep most of the e-6 chems in them with floating lids, and then microwave them to get things up to temp, and the water bath keeps them at that temp.

[Robert Hall]

I guess we are hearing from our friends to the north, who else would know so much about needing to heat the soup. I bow to your experience!

(thanks!)

[MaximusM3]

Bought this two years ago and works fine with 11x14 trays. At the minimum setting, keeps lith developer at about 100 degrees, which is what I use. http://www.amazon.com/Cuisinart-CWT-...21302875&sr=8-