Tips for setting up bathroom darkroom (ventilation, light sealing)

[Grim Tuesday]

For the past few years, I've lived in a house where I have an extra room to use for the darkroom where the laundry machines are. I have baffled cardboard boxes I made (one for intake, one for exhaust) to maintain airflow, and I cover the window with black plastic garbage bags affixed and removed with velcro. I have a normal house fan that pushes fresh air through the baffled box into the room where the door would be (this room has no door -- I cover the door hole with the plastic and cut a hole for the vent) and I assume it exhausts through the other box. It works acceptably at best: I have minor light leaks from only using one layer of velcro, the black plastic bags, even though triple layered are still only light tight at night time, the airflow could be better, and there's no running water.

But, I am moving to a new place with no extra rooms so the bathroom will be my new darkroom. It's a relatively large bathroom, and I'll be delighted to have running water (before, I had to leave the darkroom to go to the kitchen sink to wash prints). I am looking for tips on how to achieve ventilation and light sealing. The bathroom has a door, a full size window and no ventilation fan. Two challenges I would be interested in hearing how other people have dealt with is:

1. How to light seal a window, but also put some kind of baffled, powered vent in there. Bonus points for something that can be stored easily and unobtrusively when not in darkroom mode, and deployed quickly and easily. My old system with velcro trash bags was ugly, not fun to hang up, and also the only way to store it was to stuff it in the cabinet, which not only took up the entire cabinet but I think a family of mice moved in to it at some point.

2. How to light seal the door, but also keep air flowing for intake

 

[Doremus Scudder]

Your bathroom likely has a ceiling fan already that you can use for ventilation. If not, and it's possible, install one making sure the ducting hose (in the attic? or wherever) is looped once to make it light tight.

If you've really sealed the room, you should install a light-tight vent that has a filter in it. Then, when you run the fan, the air entering will be filtered. Vents don't have to be large. You could install a small 6" square vent in a hollow door with a filter in the middle, or install a vent in the wall (a bit of drywall work, but worth it!).

The door to my current darkroom is lightproofed with commercially available weatherstripping and a standard threshold glued onto the linoleum floor. I added a sweep on the inside of the door. I can't see light through it after 20 minutes of adjustment. You should be able to do that too.

When I used a bathroom for a darkroom, I sealed the window by making an insert out of black foam core or thin plywood/Masonite that fit exactly inside the window frame. I added to that some taped-on strips of plastic lightproofing (old paper bags work well) that sealed around the edges. That and a roller blind in the window did the job just fine.

FWIW, I also made a sink out of plywood and 1x4s that fit exactly over the tub. It stood on four pipe legs with suction cups on the bottom and into pipe fittings on the bottom of the sink. A simple drain with a hose into the tub and a fitting to get tempered water from the shower head and I was in business. The sink and plumbing took only 5-10 minutes to set up and take down. I have the sink in storage somewhere still... I don't use it anymore since I built my dedicated darkroom.

My enlarger was mounted on a rolling cabinet that simply rolled into the bathroom. It was a Beseler 45MX. It rolled in and out pretty easily and stored in the garage (with a garbage sack cover) along with the sink when not in use. When I printed, I'd set everything up and leave it for a day or two, then take down and reconvert the darkroom back into a bathroom. For developing film, I simply used trays on the countertop and washed with a film washer in the sink.

Hope this helps,

Doremus

 

[Donald Qualls]

Doremus pretty much echoed what I was going to reply, except my window cover was made with a frame that fit inside the (old style sash type) window frame, plywood cover mounted on that, and a "cuff" of black-core foam board that overlapped the molding strip on the outside of the window frame -- all of that spray painted flat black on both sides. If it's going to be a semi-permanent installation, you could use weatherstripping instead, to ensure it's light tight.

As for air ingress, the plumbing under the vanity won't be anything like airtight, so the exhaust fan (assuming there is one) can draw air from there -- from under the house, ultimately, or along the plumbing if you're upstairs.

 

[Paul Howell]

You can use Clayton low odor chemistry, stop and fix from Freestyle. Clayton developed it's line for use by the Navy for ship board use. Also T4 fix from Photographers Formulary is low odor. If counter space is limited get a motor base and few paper drums, usally used for color work they work really well with black and white as well and has a very small footprint. Although I have counter space when printing a small number of prints I use a motor base and drum, takes a lot less chemistry.