Introduction: Knock-Down Shelves
For years, my books have lived in milk crates, cardboard boxes, and endless piles. Given their impact on my quality of life and my work, I decided it was high time I fixed the situation and gave these little slabs of knowledge their own sturdy, permanent home.
I moved (again) at the beginning of August, so the solution had to be light, portable, and cheap. The Knock-Down Shelves provide twelve running feet of book storage, all carved out of one 4' x 8' sheet of plywood. Twelve bolts hold the hold thing together; pop them out and the shelves dissolve into 5 1' x 4' pieces, stackable and packable. Raking 5° from bottom to top, the shelves change width to accomodate different items. The cut edges of the plywood are painted with bright yellow enamel paint, an easy solution to hiding the unattractive inner plies. The surfaces are treated with a mixture of boiled linseed oil, polyurethane, and thinner that penetrates and protects while adding a slight warm tone to the wood.
I used a nice sheet of Baltic birch plywood, though any 3/4" stock will do. Add in some glue, hardware, and paint, the whole shelf should run about $60. I built it in a day. It can be done entirely with a circular saw if need be; I included instructions with the table saw because that's how I did it.
You will need these materials:
1 4' x 8' sheet of 3/4" plywood
Trim head #6 x 1-1/2" screws
Handful of 1" screws
12 3/8" x 2" bolts
12 3/8" nuts
24 3/8" washers
Enamel paint of your choice
3/8" dowels for plugs
You will need these tools:
Drill/driver with 3/8" countersink bit
Optional but helpful:
Step 1: Cuts
In a relatively simple project like this, made from flat, straight sheet goods, the fastest way to get it done is to cut everything first, then assemble the pieces.
I started with two pieces that were 3' x 4' and 1 piece that was 2' x 4'. I had to get the full 4' x 8' sheet cut down at the hardware store to fit it all on my roof rack.
First, use a circular saw with a clamped straightedge to cut the sides. They are 47-1/2" tall, tapering from 8" to 12" over 42". In other words, the taper starts 5-1/2" off the ground, allowing for a double-thick "foot" on each side. This taper works out to approximately 5° off of vertical.
With two sides cut, now cut three shelf backs and three shelf fronts. Each shelf is essentially an open box; this makes it structurally stiff and allows it to act as both shelf surface and lateral bracing, eliminating the need for a back or diagonal braces. The backs of the shelves are 4-1/2" x 48"; cut three of them. The fronts of the shelves are 2-1/2" x 48", each edge beveled parallel to one another at 5° so that they will eventually match the taper of the side pieces.
The shelves themselves are 8-1/4" x 48", 9-1/2" x 48, and 10-7/8" x 48".
You can make all these cuts with a circular saw; be sure to clamp a straightedge to run the saw against for straight, clean cuts. Use a new framing or laminate blade to help prevent chip-out and splintering of your veneer faces.
I used a table saw for most of these cuts, which is more accurate, faster, and cleaner. If you have access to a table saw, use it for sure.
The whole shelf works within the 48" logic of a sheet of plywood to try and be materially efficient and eliminate labor. If you want a narrower shelf, change the dimensions to suit your space.
Step 2: Shelf Assembly
Each shelf forms an open-bottomed box. The back long side of the box projects above the surface of the shelf to form a 1-1/2" high barrier that prevents books and small items from slipping off of the back of each shelf.
Plywood is prone to splitting when you fasten into the edges, as the screws or nails tend to pry the plies apart. To prevent this, use small (#6) trim-head screws and pre-drill each hole carefully. I used a new brand of screw (not a paid advertisement or anything, but they worked well) called Spax. They had a special make that was specifically for going into the edges of plywood.
Glue and screw the shelf together. Four screws along each edge should be enough to draw things tight. A clamp or brad gun is helpful to keep things aligned and flush when pre-drilling and screwing. I don't have a photo of it, but go in
I went back and filled the holes with maple plugs, but that's an optional step.
Once each shelf is assembled, sand and finish it with your choice of stain or clear coat. Be careful when sanding so as not to go through the veneer. I used a mixture of 40% boiled linseed oil, 40% polyurethane, and 20% thinner, which is a thorough, penetrative clear coat. Paint it on thick, let it absorb into the grain for about ten minutes, then buff off the excess with a clean, lint-free rag. This mixture is cheap, durable, and easy to apply.
Step 3: Final Assembly
Start by laying out the centerlines for the shelves on each end piece. The bottom of the first shelf starts at 5-1/2" off the ground (mind you, the bottom of the box, not the underside of the actual shelf piece), so the centerline is at 6-3/4" off the ground. The next two are at 22" and 35-1/4"; this creates a 12" (vertical space) and two 10" shelves once the depth of the boxes are accounted for.
Screw and glue an additional piece of plywood onto the foot end of each side of the shelf. This piece should be approximately 5-1/2" x 12", and will go a long way to providing more secure footing for the structure.
Drill two holes on each line, beginning with a 1" counterbore that only goes partway through the piece, then following with a 1/2" bolt hole that goes fully through the piece. Using a 3/8" bolt, the 1/2" hole will provide tolerance room to get the shelves on. The shallow 1" diameter hole is perfectly sized for a 3/8" cut washer. Drill corresponding 1/2" holes in the sides of the shelf boxes.
Paint the edges of the plywood if so desired. It will take several coats as the open grain of the interior plies is thirsty and draws paint down. A good sand and a coat of primer will help. The most time-consuming part is just taping off all of the edges for a clean line.
Finally, lay the shelves on their backs and put the sides up to them, align all your 3/8" x 2" bolts and ratchet them down tight. Stand it up and load it down. It should be more than strong enough to be a step ladder in a pinch.