Okay, y'all were right... but how to control temp?

[kevin_krumwiede3]

I'm looking for some practical advice on how to control the temperature of B&W developing and printing solutions. Where I used to live, I had the convenience of a concrete slab directly under my bathroom floor which kept my 5-gallon bucket of tempered water at a fairly constant 72 degrees. Now I have an upstairs apartment, and the ambient temperature varies wildly. I tried placing my beakers of working solution into trays of warm or cool water and stirring them, but my thermometer responds so slowly to temperature changes it's difficult to nail it down. Should I invest in a digital thermometer? Or am I approaching this entirely the wrong way?

 

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Thanks...

 

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Krum

[conrad_hoffman]

For printing, I don't worry about it. Whatever the ambient

temperature is, that's my printing temperature. For film I got a big

gray plastic dishpan like they use in restrarants. I fill this with

water at whatever temp I want to process at. The chemistry goes in

beakers that get quickly adjusted to temp in a pan of hot or cold

water. Then they go in the dishpan. I also set the SS tank in the

dishpan when I'm not agitating so the heat of my hand doesn't affect

it. Any good dial or liquid thermometer should react within a few

seconds to temperature changes- what are you using for a thermometer?

I find the dishpan will hold temperature within about a degree for

the ten to fifteen minutes it takes me to do a roll or two.

[gene_crumpler18]

A possible answer for your situation is to use Diafine for developing

film. It is insensitive to temperatures between 70 and 85 degrees,

as well as time and agitation variations. It is pretty fool proof.

 

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For printing, the temperatures are not real important unless you have

extreme temperature swings say over 80 degrees. If you know that the

temperature only varies between 70 and 80 degrees, I wouldn't worry

about print solution temperatures.

[kevin_krumwiede3]

Gene, I guess I should have mentioned that I am currently using 35mm

TX and HC-110. (How quaint, I know...) I love the way TX looks and

don't mind the grain since I rarely print anything larger than 5x7

for my album. I thought about using XTOL but nobody had any around,

and I haven't come up with a compelling reason not to simply stick

with what I know... since I don't know anything very well yet and

probably wouldn't know the difference...

 

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My thermometer is made by Kodak. It's an alcohol thermometer affixed

to a paper scale and enclosed in a glass tube. The bulb of the

thermometer is not in contact with the glass, but apparently

insulated from the outside by the air in the tube. It didn't make a

whole lot of sense to me when I bought it, but I figured hey, it's

from Kodak! Waste of ten bucks.

 

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Krum

[pete_andrews]

Buy yourself one of those little digital thingies with a metal probe.

I just got one from a market for #2 ($3US or so)! It's easier to read,

faster reacting, and less breakable than my certified mercury/glass

thermometer. They both read the same within +-1/4 degree.<p>Anyone

want to buy a certified mercury thermometer for #10?

[christian_harkness]

Krum, if you are using Tri-X and printing to only 5x7, I am not sure

fussing about the thermometer will make any difference.

 

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chris

[terry_carraway]

Kodak makes better thermometers that are not too expensive. So does

Jobo. Of course, you can buy them even cheaper used on eBay.

 

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If you get a cheap digital, make sure you check it at the temps you

are running. People seem to believe that since they read out to a

tenth of a degree, they are accurate to that, NOT. You have to get up

to the couple hundred dollar range to get accuracy in the degree

range.

 

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With Xtol at least (I just did some HP5+ in Xtol so I have the info

handy) there is a significant difference in time from 70 to 72

degrees, so accuracy is fairly important.

 

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One thing to watch with any wet (alcohol or mercury) thermometer, is

that in shipping you may get separation in the liquid column. To fix,

get a pan of very hot water, and carefully dip the bulb in and out to

raise the column to the top. This will reconnect the liquid column.

 

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I ran into this this weekend. Things didn't seem right, so I checked

my one thermometer against my Kodak Process Thermometer (VERY

accurate) and found a separated liquid column. A little hot water and

it reads within about 1/2 degree of the process thermometer.

[bill_zelinski]

Whats been working for me lately is keeping a jug of distilled water

in the fridge and then using that to mix with another jug at room

temp. Don't know about your area but in mine I find used darkroom

thermometers all the time under $10.00, sometime for as little as

$3.00..

[kevin_krumwiede3]

Chris, you're right, but that's beside the point. :o) I want to

develop a good working teqchnique so I'll be able to do things

accurately when I start experimenting with less forgiving materials.

 

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Thanks, everyone, for the advice. Sounds like I was right about

needing a better thermometer.