IntroductionDarkrooms and windows would seem to be incompatible. Yet almost every photographer I've ever talked to has had to face the prospect of closing off a window in a bathroom or bedroom in order to make a darkroom. This usually happens in an apartment, and most landlords look askance at permanent modifications to their property.
All kinds of solutions to this problem have been tried-with varying degrees of success. These have ranged from a real thick coat of paint to black trash bags and duct tape. I wanted something a little more certain, yet easily removed when needed-like when that extra bedroom is needed for a guest who might like to see out the window.
This window blocker is a plywood covered frame that fits tightly into the
opening and is secured by pressure from some light bolts. It should not permanently
mar the window frame, or require making any holes in the existing window.
- 1 X 2s - poplar or maple
- 1/4" plywood
- finish nails
- carpenter's glue
- paint and/or stain and varnish
- 1/8" plastic or 4-ply mat board
- some foam insulation strips or black tape
- drill and bits
- router with bearing-guided flush cutting bit
1: Measure window openingDifferent styles of windows require different frame placement. In some case the blockers can be almost flush against the glass. In other situations the frames will have to fit the finish trim at the inside of the window. Whatever the placement, the opening must be measured accurately. It is a good idea in older buildings to measure all four sides of the window and verify that it is square. Settling and shifting may have altered the window shape.
2: Build frame
1 X 2 lumber is cut and assembled into a frame like that shown here. The center bar of the frame is intended to keep the plywood flat. You may not need this if your window is small, or you may need several cross bars for an exceptionally large window.
The number and location of t-nuts in the frame will depend on the size and proportions of the window. 6 is typically more than enough for a household-size window. Each t-nut is set into a notch cut in the face of the frame. These notches have to be deep enough to accomodate both the head of the t-nut and the thickness of the plastic or mat board being used as a pad. Cut the notches with a router or hammer and chisel. T-nut notches should be cut and the nuts inserted before the frame is assembled.
The frame itself can be assembled with finish nails or screws as you choose.
Check the fit of the frame in the window opening before adding the plywood covering. If the window or the frame is out of square, twist the frame until it fits with even pressure all around, and tack nail a small diagonal brace across the frame to hold it to shape until after the plywood is attached.
3: Cover frame with plywood
Cut the plywood for the blocker slightly oversized for the frame. Glue and nail it to the frame with a bit hanging over all four sides. When the glue has dried, use a router with a flush-cutting bit to trim off the overhang.
The frame should be finished with paint or varnish as you choose. This will
control any dust and make the surface easier to keep clean. It is a good idea
to paint the surface of the plywood a light color in order to reflect sunlight.
4: InstallationThread a bolt into each t-nut from the inside of the frame until just flush with the face of the nut. Insert frame into window opening. Slip a piece of plastic or mat board into place over each t-nut. Tighten the bolts against the window. The narrow gap which remains between the frame and the window is then sealed with foam weatherstripping attached to the frame only. If you are less woried about paint damage, you can use opaque black tape to seal the crack.
Dale Austin firstname.lastname@example.org
All images and text copyright 1977-2003 Dale Austin