Humidity and its relation to darkroom sanity

[Rob-F]

Up early. Coffee. In the darkroom by 9AM Sunday morning. Ah, now for a full day of printing. Not. 6 x 6 negative in the DA900 carrier. Carrier on the lightbox for the final check for dust. Oops, a little dust and stuff there. No problem, that's what the dust brush is for. Hmm, it's still there. OK. Large Rocket blower bulb. Funny, it's even dirtier now.

(1/2 hour later) Rocket blower, 2 different brushes, kimwipes, spray mister. It looks just as dirty now as when I started. Wipe very slowly, so as not to create static charges that attract dust.

Static? Dust? Better go look at the humidity dial on my junior weatherman outfit. Aha, it is 29 percent! Dry air = static charges = dust on negatives. Honey, don't we have a vaporizer/humidifier someplace? Upstairs hall closet.

Set up vaporizer in the darkroom. Give it 20 minutes to do its thing. Ah, much better. Nice warm, moist steam. No more static charge. Negative cleans right up. Perfect print.

(Later) Prints are on the drying rack. Funny, something is dripping on that one print. Water pipe overhead. I don't think it's leaking, though. It is carrying cold water to the temperature regulator for the wash tray. Boy, that water pipe is COLD. Well, it is a cold water pipe, and it's February. Must be condensation. Sure, moisture is condensing on my overhead cold water pipe. But why would it, in this low humidity and dry air? Had this darkroom 11 years, never happened before. Oh, the vaporizer. I set it on the floor, right under the cold water pipe. The steam is going up and condensing on the cold water pipe. Is this because I am printing pictures of steam locomotives?

Vaporizer gets moved to the counter. NOW everything works right. No dust problems. No water dripping on prints. Smooth for the rest of the printing session.

Moral: A darkroom is a finely tuned system. You can't change anything without affecting something else!

 

[KenR]

I have not experienced the static cling dust problem that you write about, but I have a winter print curling problem. In the summer, when the humidity in my basement darkroom is high and the dehumidifier is going off, my fiber prints dry flatter and if they have some curl, a book or two of weight cures the problem. In the winter, when I do most of my printing, the darkroom is drier and the prints curl more and are so stiff that even a fairly heavy weight doesn't cure them. I dry mount the good ones and that certainly gets them flat, but an occasional print is ruined by edge wrinkles caused by the flattening process. I've tried leaving a tray of water in the darkroom as the prints are drying, but it doesn't seem to really help.