making and keeping temps?

[jano]

What's the best way to make and keep temperatures?

My tap water in winter and spring often comes out between 16-20C, but in the summer it will go up to 22 or 23C.

As I try to write this, I'm getting mixed up in the possibilities.. so here are the categories:
1. warm the cold chemical to temp
a) no dilutions, e.g. diafine
b) small dilution, e.g. rodinal
c) larger dilution, e.g. xtol
2. cool the warm chemical down
a) no dilutions, e.g. diafine
b) small dilution, e.g. rodinal
c) larger dilution, e.g. xtol

For 1a), i fill my sink with hot water and swirl the difine containers in them until I get to between 23 and 27C (I also continue to run hot water over them). Then I remove the containers, pour A into the tank and develop from there. Solution B drops temp in the meantime, but I figure it drops at the same rate as A in the tank, so there's no harm? Can I keep the temp?

For 1b), I run hot tap water into a measuring cup of cold water until I get the right temp.

For 1c), I measure temp of the chemical, then subtract that from my desired temp. Then add that number to the desired temp and bring hot water to that temp, and mix.. so far, always been spot on.

I think I've got the 1's pretty much covered, just not sure how to keep the temperature for 1a).

Anyway, the 2's are hard. How do I do it quickly? Ice bath? Refridgerator? Say, for 2c), both the coldest tap water and the chemical is still warmer than my desired step?

Or is all of this unecessary, and I should just keep notes on what times to use with what temps? That's kinda what I did for 1 and 2 c) when I used Xtol from fall through winter.

Jano

 

[kaiyen]

Jano,
Well, keeping notes and just adjusting dev times for temperature is one way, but I think it's wise to at least try to get everything to the right temperature from the outset.

One thing I do is make a big bucket of water at 68F. This way, I have a known temperature. I do this with a combination of cold & hot tap and ice packs, depending on time of year. There's enough water there that it will not change temperature much during the time it takes to do the 1-2 tank I do at a time.

For keeping things the right temperature during processing, you can get a big 16x20 tray and put 1-2" of 68F water in the bottom. It'll keep your tanks and beakers somewhat more consistent.

For cooling chemicals down, one thing that many people do is to keep a jug of water in the fridge just for this. I just take a 1 gallon graduate with cold tap and throw a couple of the ice packs in there before I start setting up. By the time I get the film loaded and supplies set up, it's usually cold enough to use for cooling things down when mixing.

allan

 

[wtl]

i don't get that technical and my darkroom is a simple faucet. i use a bigger container with either ice water or hot water, and place the chemical mixtures in it to control the temp.

 

[jano]

Ah, cool.. keep water in the fridge! Duh! Perfect!

Thanks for the help from both of you.
Jano

 

[tkluck]

Then:
Digital thermometer to adjust tap. Then fill sink. Sacrifice chicken.
No one could see me crying under the safe light.
Now:
Diafine at room temp. Scan. Photoshop. Tell my self that inkjet paper is cheaper than polycontrast. Ignor cost of Ink.

Good thing I'm having fun. Otherwise I'd go nuts.

 

[derevaun]

An ice chest full of water at the taget temperature won't change temps before the whole process is finished, unless the room temperature is a lot hotter or colder. Cooling the water is actually easier than warming it up: just swish an ice pack through it and it'll cool quickly. It's hard to do that with a heat source.

 

[vicmortelmans]

some very good suggestions overhere! I'm troubled as well these days: tap water as hot as 26 degrees celcius! This even out of range of the typical temperature curves documented for the developer (which I hesitate to use anyway).

Keeping a large bottle of 'cold water' in the fridge is a good idea. Actually, I do the same in winter, when tap water goes down to less than 10 degrees, by keeping a large bottle available at room temperature (which is ~20degrees).

Groeten,


Vic

 

[Todd.Hanz]

During the summer my tap temp is 74.5F, so I use cold water from my cold water dispenser in my fridge door to mix the temp down.

Todd

 

[vicmortelmans]

by the way, if my calculations are right, this is how to produce 1l of 20-degree water if you have a can of F-degree water in the fridge and tap water of T degrees:

the amount of tap water you require equals (20-F)/(T-F) liter and
the amount of fridge water you require equals (T-20)/(T-F) liter

In my case, with the fridge on 5 degrees and the tap at 26 degrees, I need 15/21 or ~ 3/4 of tap water and ~1/4 of fridge water.

Groeten,

Vic

 

[jano]

the amount of tap water you require equals (20-F)/(T-F) liter and
the amount of fridge water you require equals (T-20)/(T-F) liter

Ah, that's helpful. I don't remember my chemistry well enough. So far, I've been doing it the easy way, where if water from the tap was, say 26, I'd mix equal amount with water from the fridge that was at 14. But it's a pain in the arse bringing fridge water to 14, so sometimes I'd just slowly mix in fridge water until the temp was right. Using the formula will make things quicker! 🙂

 

[GeneW]

What I've been doing for years is storing tap water in one-gallon glass jugs (old cider jugs) in a closet, alongside my jug of fixer and a jug or two of distilled water. The temperature stays within tolerable ranges for development, so I dilute my dev solutions using the stored water and have consistent temperatures throughout the cycle. I wash the film in the stored water (Ilford wash method) and final rinse and PhotoFlo in distilled water. I adjust dev times relative to 20C. Works for me.

Gene