Hide Sheet-good Edges Like a Pro
Super-stable plywood and medium-density fiberboard (MDF) simplify construction by freeing you from the concerns of using solid-wood panels that shrink and swell with the seasons. But plywood's layered edges don't pack the appeal of solid wood. Here's how to simply, affordably, and effectively hide the ugly edges.
Stick with solid-wood edging when possible
Sure, you could apply pre-glued, iron-on veneer tape, shown above, to your sheet goods. This product, sold in a bulk roll, has thin edges that can hardly be seen, it goes on quickly with heat, and you don't need clamps. But for most projects we still prefer solid-wood edging because it offers these advantages:
■ Durable. The added thickness of solid-wood edging resists chipping better than fragile veneer edging. And today's woodworking glues hold much better than the heat-activated adhesive on the back of veneer tape.
■ Economical. Cut strips of edging from those long off-cut scraps you can't use for anything else. And if you run out, a single plank yields enough edging for a raft of shelves.
■ Stiff. Adding a hardwood edge, especially one wider than a plywood or MDF shelf's thickness, stiffens it to reduce sagging—a potential downside to using sheet goods.
Make your own edging
You've got two choices here. The simplest is to rip and then glue solid-wood strips to the plywood or MDF edges with a common butt joint, shown above left. In 3' or shorter lengths of 3⁄4 " plywood this joint will be plenty strong. When you go this route, make an effort to match the edging's grain pattern and color to the panel's veneer because you want the transition to be unnoticeable. Make the edging as thick as you want. Wider and thicker edging, shown above right, adds greater stability for project parts, such as bookcase shelves, that might sag when weighted down with books or collectibles.
Specialty edging bits add mechanical advantages
Some router-bit manufacturers make two-piece V-groove and tongue-and-groove edging sets [Sources], shown below, that create self-centering, mating joints. They provide greater glue surface and assemble quicker than butt joints, which can slide around on wet glue. These joints prove ideal for edging not just shelves, but also case sides because you can set them to rout crisp veneer-like edges (see "flush" examples below) that make it easy to hide the seam of a solid-wood edge. For greater strength that will ward off shelf sagging, increase the thickness of the edging.
It takes a little more time to set up and machine the two parts on your router table, but if you keep a scrap with the final routed profile, you can use it to set up the bits the next time, saving yourself valuable minutes. Here's how to use these bits:
■ Stick with the router table. Except for large, cumbersome workpieces, such as a tabletop, use these sets in your router table rather than a handheld router. You'll appreciate the extra support and control the router-table surface and fence provide.
■ Don't overcut. Because the cutting edges on these bits typically measure 1" tall, the bearings don't help when routing the groove in 3⁄4 " (or thinner) sheet stock. Instead, set your router table's fence so the bits remove just enough material to leave a crisp veneer edge without reducing the panel's width or length. Remove more material than that and you'll need to shim the outfeed fence to make up the difference between the original edge (against the infeed fence) and the newly routed edge.
■ Rout the sheet first. Rout the groove in your sheet goods first, making test cuts in matching scrap stock until you've got it perfectly centered. How will you know? After making a test cut, flip the scrap piece so the other face rests on the table and rout a few inches. When the bit doesn't remove any material on the second pass, it's centered.
■ Now fit the solid edging. For safety, begin with a hardwood blank at least 4" wide. Plane the blank 1⁄8 " thicker than your plywood or MDF. (This will be trimmed off after installation.) Now rout the tongue profile in scrap stock until it's centered. Rip the edging from the blank to the desired width.
■ Go with bar clamps. To clamp solid-wood edging to sheet stock, avoid using F-style clamps with circular jaw pads that rotate with the handles as you tighten them. These can cause your edging to slip off the mark. Instead, use parallel-jaw clamps or one-handed bar clamps with jaws that don't rotate.
■ Size your panels after edging. To avoid mistakenly cutting single-edged shelves undersized after you've applied the solid-wood edging, cut your plywood 1⁄2 " or so greater than its final dimensions. Once you've glued the solid-wood edging in place, trim it even with the panel using a flush-trim bit, shown below. (We like to use a trim router for this because it's less likely to tip the way a larger router can. If you use a bigger router, clamp on temporary support pieces to avoid tipping.) Sand or plane the face of the edging smooth. Finally, rip the plywood to final width along the unfinished back edge.
If you plan to finish both long edges, simply begin with narrower plywood and make your edging thicker than needed. Then rip it to final size after the glue dries, removing equal amounts from both solid-wood edges.
■ Make it a wrap. If you prefer to wrap edging around corners, as you might on a table or cabinet top, cut your plywood and edging to size, and then miter-cut the edging to fit, as shown below. Flush-trim after the glue dries.
Plywood edging router bits: MLCS Woodworking, V-groove 1⁄4 " shank no. 5432, 1⁄2 " shank no. 7732; Tongue-and-groove 1⁄4 " shank no. 5433, 1⁄2 " shank no. 7733; 800-533-9298, mclswoodworking.com.
Infinity Cutting Tools, V-groove, 1⁄2 " shank no. 61-505; Tongue-and-groove, 1⁄2 " shank no. 61-506; 877-872-2487, infinitytools.com.