Building a Fixed-Shelf Unit
Whether you need a freestanding or wall-mounted shelf, a basic box with fixed shelves is sturdy and can be adapted to most any style. Freestanding units can be stacked and moved into new and different configurations; several wall-mounted units can be combined for ease of installation. Beginner carpenters can make this unit. Butt-joining the outside corners produces a clean-looking joint with little trouble. If you have some carpentry experience, you may want the cleaner look of mitered joints. Try mitered joints only if you are sure of your ability to make perfectly straight miter cuts; gaps will ruin the project.
To support the shelves, simple butt joints can be strong and stable if fastened with screws. Or reinforce a butt joint by attaching a cleat under the shelf. A dado joint is the strongest and virtually guarantees that the shelves and the outside pieces will not warp. When you get the hang of dadoes, cutting them is not time-consuming. The shelves are simple and require precise cutting. Before starting, test your power saw with scrap pieces to make sure you can cut perfectly straight and square without raising splinters. Use a sharp blade. Often it is possible to stack pieces roughly cut to length and make the final cuts on several shelves at once.
Finishing or Painting a Shelf Unit
Painting a cabinet can be very time-consuming, especially if you need to brush on two coats. Painting boards before they are put together is much easier and faster. Give the boards a primer coat before assembly. (Many primers dry in an hour or less.) If you want two coats of paint over the primer, apply one coat before assembly.
If you need to paint a number of units, consider buying an inexpensive paint sprayer or renting an airless sprayer.
Staining assembled shelves is difficult; it’s hard to get a consistent color in the corners. Stain the pieces, assemble them, and then apply a finish.
1. Cut outside pieces. For precise miter cuts, rough cut the outside pieces slightly longer than needed, then cut the miters. Place the two verticals side by side, and clamp them firmly. Draw dado layout lines for each shelf, and use a scrap piece of shelf to make sure you have marked the width correctly. Cut the dadoes 5/16 inch deep using a circular, radial-arm, or table saw. Clean out the dadoes by chiseling out the waste. Then use the chisel to smooth the bottom of the groove.
2. Assemble and measure. Join the pieces to form a rectangle by drilling pilot holes and driving 2 1/4 inch finish screws. Check for square continually as you fasten. Measure from dado to dado for the lengths of the shelves before cutting the shelves to ensure the best fit.
3. Tap shelves into place. Carefully slip a shelf into both dadoes. Tap it down using a scrap of wood to keep from marring the shelf edge. Avoid tapping one end down farther than the other; alternate between ends every inch or so or gently tap the middle of the shelf to work it into place. When the shelf edges are flush with the edges of the outside pieces, drill pilot holes and drive screws to reinforce and tighten the joints.
4. Add the back. Cut a piece of 1/4-inch plywood 1/4 inch smaller than the shelf unit in both directions. Center it on the back so there is a 1/8-inch reveal all around. Drive 4d box nails every 6 inches or so.
Installing Adjustable Shelves
Inside a frame, support adjustable shelves near each corner and in the middle of the span if needed. The most common method is to use metal support strips with clips, sometimes called pilasters. Attach them to the inside faces of the side pieces, or cut grooves and set them in. You can also opt for one of the pin methods. The important thing is to get all four supports level with one another. Work systematically and double-check often—it’s easy to misalign the supports.
The total system. Space clips as you would other supports. If the span between vertical outside pieces is too great, install a center stile with a support strip attached. The shelf must be wide enough to fit snugly between the stile and the rear support strip.
1. Mark for cutting strips. Cut one piece to the desired height. It doesn’t need to extend to the top of the unit, just a notch or two beyond the top shelf. Use the first piece to measure for the others. Line up the slots. To help position the clips later, line up the numbers as well.
2. Mark and cut dadoes. Position each strip an inch or so from the edge of the unit, and trace lines. (If you want to set the support strips into dadoes, remember to cut the dadoes before beginning to assemble the shelf unit.)
Tall Units Need A Fixed Shelf
Place support strips on side pieces that are stable and strong; if they warp, the clips may no longer support the shelf. Support strips will add some rigidity, but not much.
If the vertical pieces are made of 1-by lumber and are longer than 4 feet, install one fixed shelf about halfway up to ensure that the sides do not bow outward. Attach the shelf with a butt joint or a dado joint. Then install support strips or pins above and below the fixed shelf.
3. Attach with screws. Position the support strip and use an awl or sharp pencil to mark for the screws. Drill pilot holes with a drill bit and a depth guide so you won’t drill through. A piece of tape wrapped around the drill bit will serve this purpose. Drive screws to attach it.
Pin options. For an inconspicuous support system, drill holes at regular intervals and insert pins. Metal (or plastic) pins come in two types, a flat pin and a bracket pin. Or cut lengths of hardwood dowel to fit into the holes. When using pins, the shelves must fit tightly; if there is more than a 1/8-inch gap between a shelf and the vertical board, the pin could work itself loose and cause the shelf to fall.
Tips for Drilling a Grid of Pin Holes
If the shelf unit has one or more vertical dividers in the middle of the unit, avoid placing holes directly opposite each other on the divider, or else the holes will meet and poke all the way through. To prevent this, offset the vertical lines by 1/2 inch or so.
Save yourself time by drilling only as many holes as you really need. The grid need not extend the length of the vertical board. Start at the lowest possible position for the bottom shelf, and end at the highest possible position for the top shelf.
To space holes, use pegboard... Cut a piece of perforated hardboard (pegboard) to fit into the space, and use it as a guide. Note which end goes up, so you always align it the same way.
...or use a square. Draw vertical lines about an inch in from the front and rear edges of the unit. Measure with a framing square or tape measure, and mark evenly spaced horizontal lines at one of the vertical lines. Then use a square to copy the horizontal measurements onto the other vertical line. Use a drill bit depth guide so you don’t drill through the standard.