Lightproofing a sauna...

[kavandje]

So I've been given tentative permission to transform a sauna in my mother's house into a print darkroom.

Advantages: it has its own door into a bathroom, it has good ventilation, and it's big enough to accommodate a 6x6 enlarger. It's "intimate" in terms of space, but do-able. There's access to electricity, there's access to water, and the temperature is easy to control.

Problems:

Big honking window, and big honking glass door.

So I'm wondering if I can block out the windows by means of black vinyl adhesive panels as used in signmaking.

And I was also wondering if there's a translucent red vinyl that can be used as a 'safelight' window ... any thoughts on this? Maybe by putting big red photographic gel filters on the window and sticking them in place behind the black vinyl?

 

[John Koehrer]

If you're going to be loading film into tanks, the red isn't going to help.
People have used black trashbags to block windows & doors before, not difficult to do but annoying as it folds & sags. Cardboard taped to the frames or even building a light weight frame for the black plastic would work & make the covers much easier to handle if you need to take them down.

 

[Ulrich Drolshagen]

Hardware stores sell black pond liner from large rolls. It's absolutely light tight.

Ulrich

 

[kavandje]

Loading film into tanks isn't a problem, since I'm using a changing bag for that anyway.

The pond liner is a good idea; thanks!

 

[BetterSense]

Aluminum foil is also light tight, even to a high-powered flashlight at close range. You know what is also completely light-tight that I just discovered, is here in Dallas Walmart sells black-on-black foamcore that is totally lightproof and only a couple bucks a sheet. I started using it for pinhole cameras. It also passes the flashlight test.

 

[jeroldharter]

First off, I am wondering about a sauna in Namibia! How many of those exist?

If indeed anyone else in Namibia might have need for a sauna, then you might want to leave the room in a state that the sauna can be reconfigured if you move out of the darkroom or sell the house.

Some people will make removable wood panels that fit over the window. The door window could be blacked out with the pond liner +/- a black curtain on the inside to block any stray light around the edges of the door.

If you have a darkroom, get rid of the changing bag. Those things are awful and can be dust magnets. I would not like the "safe-window" idea because you are going to need a safelight anyway and the intensity of the safe-window will vary making a paper fogging test difficult.

 

[Larry Bullis]

I worked in a commercial darkroom that had a large red window. I believe it was plexiglass. It worked quite well. It aided in communication with the production manager. He could hold up a print and point at what he wanted changed and voices could be heard, as well. More important, it enabled the printers to see when the boss was coming so they could hide the beer.

 

[nickandre]

Gaffers tape with trashbags. Use theater light filters for the red; it might be a bit bright though.

 

[Larry Bullis]

Most black plastic isn't really lightproof. Trashbags are generally pretty thin, but there may be some very heavy material that would work better. Tarpaper stapled to a frame that fits the window or door works great but if it's hot where you are (Namibia? Really?) it may soften. Aluminum foil may be the best option if it's in the sun - cooler. You most likely wouldn't be happy if the darkroom you are working in was going to be a sauna at the same time.