Window Pain

All of us that have used temporary darkrooms (baths, laundries – you know who you are) have likely dealt with a window or two. Curtains, blinds, paper, bath towels, cement. I personally prefer aluminum foil and tape. This darkroom will be more or less permanent, or at least “dedicated”. The idea is that when and if we decide to sell the house, the room will be restored back to just a room. For some reason, having a darkroom is not the selling advantage it used to be; yet a “bonus room” is.

There is an existing 3’ x 5’ window. I could have taken the window itself out and bricked up the opening, but whatever I did, I wanted it to be reversible. (I also wanted to do it easily and inexpensively.) So, after some thought, I settled on a variation of the aluminum foil method. My preference for the metallic solution is that it is light-weight, and light proof. It also reflects heat. So, tape up the glass with solid pieces of foil, shiny side out, and the window will not transmit any light and very little of the Texas summer heat.

I used a piece of foam sheathing with foil on one side. This is normally used right under the rafters in attics to reflect heat away from the attic space. It is about a half inch thick and comes in 4’ x 8’ sheets. From one sheet, I was able to get a 3’ x 5’ solid piece and another that required only one splice. This gave a 1 inch thick piece of foil covered styrofoam in the window opening. A little caulk and it’s light proof and somewhat insulated. The window itself is a decent double paned specimen, so I was less worried about heat transfer than with older single glass sashes I have known. In fact, I am more concerned with condensation between the glass panels and the sheathing, but I’ll handle that if and when it happens.

My original plan was to have some air space between the two layers of foam (giving a tiny bit more insulation) and then a piece of paneling or drywall to finish out the opening. A picture frame molding around the outer panel and voile’. But while at the home center, the obvious alternative was sitting right there in the building materials bins: pegboard! I have always used pegboard in the darkroom for hanging reels, negative carriers and other such tools. I decided to substitute pegboard for the outer panel. This also led me to place the two foam panels together to allow enough space behind the pegboard for the hooks to clear.

The result was more than satisfactory, and can be turned back into a working window with minimal effort and some touch up paint.