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IanBarber
28-Nov-2017, 03:20
I have made a make-shift dark room in the attic ( 7 feet x 4 feet ) to develop my paper negatives.

There is no electricity up there and I am using battery driven LED's for the safe light. I have been watching the temperature of the room and it is about 50F most of the time which means the developer is going to stabilise to about this temp. Is this just to low to even think about developing paper negatives in trays?

pjd
28-Nov-2017, 03:59
It's not too low a temperature to develop paper, but you'll probably get fed up of being so cold yourself. I had similar problems years ago with an attic darkroom but I found some old darkroom tray heaters (with thermostatic controls) in an antique shop. Or just get a room heater with a fan, a small space should heat up quickly.

Doremus Scudder
28-Nov-2017, 04:49
the temperature of the room and it is about 50F most of the time which means the developer is going to stabilise to about this temp[/B]. Is this just to low to even think about developing paper negatives in trays?

From Elements of Black and White Printing by Carson Graves:

"... Hydroquinone is less predictable. At temperatures higher than 75F, it is aggressively active, overemphasizing dark tones. As the temperature drops to less than 65F, hydroquinone loses its ability to develop tones at all, leaving a print gray and muddy in the shadows."

https://books.google.at/books?id=0oLOAwAAQBAJ&pg=PT19&lpg=PT19&dq=hydroquinone+temperature+activity+developer&source=bl&ots=2QpsjpePok&sig=CNkhmtm0-anf4Mu4CMKX48R5lO8&hl=en&sa=X&ved=0ahUKEwjMiP3BmOHXAhUPblAKHdK9BxAQ6AEIKzAA#v=onepage&q=hydroquinone%20temperature%20activity%20developer&f=false

If you're using a common MQ or PQ developer, you are going to have problems. I'd invest in a small heater and run an extension cord up the attic stairs.

Best,

Doremus

Willie
28-Nov-2017, 06:35
Take a look at the electric heaters that look like old water filled radiant heaters. They are filled with oil which heats and circulates in them and don't put out light. One small light to tell you it is on. Work well as they are quiet and even if the power goes out they radiate heat for awhile before cooling.

50 degrees is too cool for much darkroom chemistry to work well.

IanBarber
28-Nov-2017, 06:54
Take a look at the electric heaters that look like old water filled radiant heaters. They are filled with oil which heats and circulates in them and don't put out light. One small light to tell you it is on. Work well as they are quiet and even if the power goes out they radiate heat for awhile before cooling.

50 degrees is too cool for much darkroom chemistry to work well.


Thanks. I appreciate 68 is my target, what would you say is the minimum I should be aiming for

John Layton
28-Nov-2017, 07:54
....another reason that the oil-filled heaters are great is that they don't blow dust around.

Do understand that room temperature does not always equal solution temperature...that depending upon the relative humidity, agitation/air movements, trays and sink composition (heat transfer characteristics) - your actual solutions temps. may be different (typically cooler than) your air temps...so do test your solution temps. and set your room temp. accordingly!

Alternately, there is some merit to employing a "drift-down" scenario...starting with a solution temp. which is somewhat higher than your target with the knowledge that it will decrease a certain amount over the time of a given process. If you do do this just make sure the final solution temp. at the end of the developer step is not significantly below 65F.

Do keep in mind that absolute solution temps. are somewhat less important with papers than with films.

Finally...I do believe that there are developer formulations which are designed specifically to work well in cool temps. Maybe someone with more experience with this can chime in?

IanBarber
28-Nov-2017, 07:58
After someone mentioned oil filled radiators, I suddenly remembered we had one in storage in the garden shed. Ive cleaned it up and its working.


Do understand that room temperature does not always equal solution temperature...that depending upon the relative humidity, agitation/air movements, trays and sink composition (heat transfer characteristics) - your actual solutions temps. may be different (typically cooler than) your air temps...so do test your solution temps. and set your room temp. accordingly!

Thanks John, I will do some tests tonight. Looking at this radiator, the top is pretty flat and may even allow me to place my dev tray on it

Luis-F-S
28-Nov-2017, 08:41
There may not be any electricity now but I bet an electrician can set you up

adelorenzo
28-Nov-2017, 08:50
The Darkroom Cookbook has recipes for low temperature developers.

Jerry Bodine
28-Nov-2017, 10:39
...I have been watching the temperature of the room and it is about 50F most of the time...

How about in the summer, when most attics get very warm? Will this not complicate your situation? Is your 7'x4' space a small part of a larger attic? Does your attic not have insulation on its floor to help maintain comfortable living quarters below, all year long? Depending on the type of insulation, it could be a "dusty hell."

Andy Eads
28-Nov-2017, 14:32
I made a makeshift water bath that worked well. It consisted of a somewhat larger tray filled with water, a submersible aquarium heater and a submersible aquarium pump. The pump circulated the water and the heater got everything up to temp and held it remarkably well. I think I was out about $40 for the parts. I think the maximum power draw was 30 watts.

Leszek Vogt
28-Nov-2017, 15:42
I found "seedling heat mat" to be quite useful (appropriate size for the trays) and if you get the right one, you can dial-in (digital gauge) the temp that you need in the trays, which may need some prior testing/tweaking. Anyway, get an extension chord up there and you'd be set. Don't crank this thing too much....or you might melt the trays :>)

Les

esearing
29-Nov-2017, 05:35
How big is your garden shed? It might be a better place than an attic. Especially if you have a major spill. Same challenges of water, electricity, dust, and temperature.

Wayne
29-Nov-2017, 06:38
Aquarium heaters in a tempering bath for winter (no circulating pump is needed...just experiment until you find the right temp) and ice probe tempering bath for summer. Either one might run off a portable power source, like a jump starter.

xkaes
29-Nov-2017, 08:50
I use cheap, simple, heating pads that I got at the local thrift store for a buck each (you can pick up some used extension cords while you are there as well). I put one or more under my processing troughs when I'm using color chemicals for murals (90 degrees). I don't use them for trays -- because I use tubes in heated water baths for small prints -- but heating pads should work fine for your purposes. Just stick a thermometer in the tray(s) and adjust the heat level. Add a towel underneath to cool things down, if you need to.

I've worked in a lot of dusty darkroom, but working in an attic gives me chills!

Harold_4074
5-Dec-2017, 19:18
depending upon the relative humidity, agitation/air movements, trays and sink composition (heat transfer characteristics) - your actual solutions temps

John Layton listed most of the commonly ignored factors. If you heat the space from 50F to, say, 70F, you will drop the relative humidity from whatever it started at, so you solutions will cool well below room temperature even though the room temperature has been increased. Agitation increases the rate of cooling, but tray contact with a bench or sink will decrease it. A larger tray of tempered water and a plastic cover to reduce evaporation will both help with both of these variables and probably make printing, if not film development, much more practical.

jp
5-Dec-2017, 19:55
I've noticed some fixers to not work as well in the 50-60f range. Definitely clear a scrap of film with it at your working temperature compared to normal room temperature so you make sure it works OK and to make any fix time adjustments.

JMO
5-Dec-2017, 22:08
Here in the upper Midwest, where home basement darkrooms can get pretty chilly during the winter, some of us use piglet warmers such as those made by Kane Mfg in Iowa (https://www.kanemfg.com/livestock-heating/). These are moderately priced, and really rugged and designed to be used in hostile environments in terms of urine, feces and high pressure power-washing (etc.) in farrowing barns. There are also Corrosive Environment Controllers (https://www.qcsupply.com/10048-corrosion-resistant-thermostat.html) available that can be safely used in any darkroom sink area to accurately control the warmers to maintain the liquids in enlarging trays at whatever temperature you need (through use of a probe placed inside one of the trays and along the edge, so out of the way of the paper and agitation). No need for water baths.

lab black
6-Dec-2017, 15:44
Re: Kane Warmers

Than you for the great resource.