Keeping a steady 20 degrees Celcius

[briandaly]

What's the easiest, most consistent way to get your chemicals to 20C and keep them there.
I started developing at home a few weeks ago and so far, I'm enjoying the process.
However, the most stressful part is getting the developer, stop bath and fixer all to 20C.

Currently, I'm re-using the stop bath and fixer chemicals, so I pour then out into graduated cylinders and place them in a basin of hot water to bring up their temp to 20C. However, I'm finding this difficult to control as I only have one thermometer and have to rinse it between taking readings of the different solutions.
Do you use a thermometer per solution type?
Do you use a large basin of water at 20C to keep your solutions' temperature constant?

I'd be interested to hear how others approach this.

Brian

 

[kully]

How 'fine art' are you going? 🙂

The developer is the important one for tempreture, the stop and fixer can be a few degrees out without any untoward effects.

I see you're on pretty much the same latitude as me, in winter/autumn/spring I get the water to 20.5-21C (on my thermometer) and pour it in - the relative coldness of the tank cools it down to 20C.

Perhaps you need more care (like putting the dev tank in a bowl of 20C water) if you are developing in a very cold/hot shed/loft but for normal indoors (even with the heating off) I've not had problems doing the above.

As for the thermometer, I have just one too, a quick splash from the tank is all I use when moving from dev to stop to fixer - remember that some of each is transferred to the next in any case as you can't shake out all the liquid from the tank.

So, am I talking rollocks?

 

[rpsawin]

Use tray/water bath.

Bob

 

[Chris101]

I just set my thermostat to 68F so the ambient air temperature is 20C. Then once I adjust the temp of my developer, I am assured that it doesn't change during the process. If the ambient is way off from 20, then I adjust the development time and process at a reachable temperature.

 

[briandaly]

kully, rpsawin, thanks for the suggestions.

Getting the developer to approx 20C is fairly easy as I mix new developer each time and can add as much hot or cold to the water to get it to 20C before adding it to the stock developer.

However, as I reuse the stop bath and fixer, I need to pour these into a graduated cylinder and immerse them in a basin of very hot water to bring up their temperature. I often overshoot or the temperature keeps rising when I take them out of the hot water due to the plastic container retaining some heat.
I then need a basing of very cold water to bring them back down.
If I were to also use a tray of water at 20C to keep everything stable, that's 3 basins of water! Seems like a lot of effort if I'm only developing one roll. I'm sure I'm over-complicating this and there must be an easier way.

 

[kully]

That can be problem in some homes Chris. For example, my thermostat is in the living room and there can easily be a 4-5C difference in tempreture between that and my kitchen (and the clay bottom floor is even colder).

But this is exactly what they do in the darkroom at College - the whole room is kept at 20C.

 

[briandaly]

I just set my thermostat to 68F so the ambient air temperature is 20C. Then once I adjust the temp of my developer, I am assured that it doesn't change during the process. If the ambient is way off from 20, then I adjust the development time and process at a reachable temperature.

You bring the whole room up/down to 20C ?

 

[kully]

Brian,

Someone with much more knowledge will come along and correct me - but I use stop and fixer between 16-24C and don't have problems.

 

[MartinP]

When the room temperature is too low, or too high, I fill a washing-up bowl with water at the appropriate temperature then just put the stop and fix containers in there, to adjust gradually while everything else is sorted out. If the temp difference is very big then fill the washing bowl with much warmer/cooler water to get the stop and fix more quickly to approximately the right temperature, before adjusting it to about 20C for the dev-stop-fix routine.

As you say, you only need one thermometer, just mix the dev to the right temperature when the stop and fix are more or less right and (if necessary) you have refilled the very-hot/cold washing-bowl with 20C water. The tank can sit in the bowl too, if you have a long developing time and a very cold/hot room temperature.

Remember that the stop and fix only need to be within a couple of degrees of the developer temperature, as pointed out by Kully above. Using the Ilford washing method, you can have a big jug of 20C wash-water nearby too, but that will be so large in volume that it won't change temperature much.

There are lots of handy tips on the Ilford site, and probably on Kodaks site too.

 

[spyder2000]

Control the developer. The other solutions, including the wash should be within 2-3C of each other to prevent reticulation of the emulsion. So for many, the wash temperature governs the rest of the process.

 

[briandaly]

The wash temperature should also be controlled? I've just been using cold tap water up to now.

 

[Roger Hicks]

Control the developer. The other solutions, including the wash should be within 2-3C of each other to prevent reticulation of the emulsion. So for many, the wash temperature governs the rest of the process.

It's virtually impossible to get most modern films to reticulate without using ice-water.

Having said this, I use 20 degree water for the Ilford sequence (5 inversions; drain; 10 inversions; drain; 20 inversions; drain). Hard though it is to believe, this gives ANSI archival washing with non-hardening fixers (you don't need a 5 minute wait between washes, either).

To avoid drying marks, I normally add 10 more inversions in distilled water, then 30-120 seconds in distilled water + HALF the recommended dilution of wetting agent. Less than half, and there's no point; the full quantity, or more, and you risk streaks from the wetting agent. At least I do.

Cheers,

Roger

 

[Chuck Albertson]

Most of the year, the ambient temp in my apartment is 68F, and I use a plastic tub for a water jacket to keep the developing tank at that temperature. The rest of the year (summer) the temperaure soars a bit, and I simply adjust development time per the manufacturers' charts---all the chemistry is the same temperature. Trying to cool the chemistry down in the water jacket has never worked that well for me, and takes forever when it does. There are some stretches in the summer when it's simply too hot, so my exposed film backs up until there's break in the weather and I can process it all at one go.

 

[briandaly]

Thanks for the responses.
I'll focus on getting the developer temp correct and worry less about the stop bath, fixer and wash.

 

[Ade-oh]

Thanks for the responses.
I'll focus on getting the developer temp correct and worry less about the stop bath, fixer and wash.

That's the way ahead. A point to note is if your wash water gets too cold, it won't remove the remaining fixer very efficiently and you may need to increase your wash times.

 

[Joao]

As written in several posts there is some tolerance in temperature. If for some reason you want it to be precisely at 20ºC you can use a large bowl with water and an aquarium thermostat, set for 20ºC . Place your liquids there (in closed bottles) for a while, and you will have them exactly at that temperature. But as I said, it is not worth the trouble.
Or you can use the aquarium itself, if your tropical fish live at 20ºC 😎
Regards
Joao

 

[oscroft]

I'm another who never bothers with the temperature of stop water, fixer and wash water (that's in the UK). Fixing might take a bit longer if it's cooler, but I fix for twice the test fixing time anyway so that takes care of that (and I've never noticed much difference in test fixing time with water of different temperatures anyway).

So I get my dev to about 20.5 deg C, knowing that it will cool slightly in the tank, then I use stop water (I don't use acid stop) at a bit warmer than tap temperature (tested with my finger), then fixer at room temperature, and finally washing water at a bit warmer than tap temperature.

When I restarted developing fairly recently I was worried about reticulation at first (I've had it in the past - more than 30 years ago), but it just doesn't seem to happen with modern thinner emulsions.

 

[alexz]

Xmm, my geographical location dictates that opposite - I usually need to cool down a tap water in order to bring them to 20 deg. C... 🙂
I just fill a bowl with tap water (which is usually at approx. 23-26 deg.C), put it into refrigerator for some time (usually few hours) which brings their temp to about 12-15 deg.C. Then I mix the developer with that water and tap until the measured temp. settles on 20 deg.C +/ half degree.
Then, while the film gets developed I treat the fixer putting one into freezer for 5-10 minutes which cools it down pretty quickly.
May sound a bit cumbersome, but frankly, just a matter of exercise - after a while it gets nearly automatic...🙂


As about final wash and dipping into rinsing solution afterwards - just don't care - do it with whatever ambient temp. it is (room temp).

 

[craygc]

Singapore based... cold tap water is 29C so I just give up on 20C ...adjust times to 25C and live with it. I only lower the temp if I can't get my times over 5 mins for a particular film/ developer combo. Never had an issue yet....

 

[minoltist7]

I do two things:
1) bring room temperature to 20 C
2) fill a bowl with 20 C water and leave my chemicals there (sort of water bath )