Plywood Edging Bits
Blades and Bits
Hardwood-veneer plywood may be a woodworker's best friend: Dimensionally stable, it won't swell and shrink like solid wood when humidity levels change; it costs less than solid wood; and you can find it readily at home centers in several common species. Of course, this workshop standard has an ugly side -- or more accurately, an ugly edge.
The thin layers (or plys) of wood that make up plywood show themselves as an unattractive striping best hidden on your projects. Woodworkers sometimes glue and/or tack on a thin band of solid wood to mask the plys, but a mismatch in grain or color can belie the fix. Thin iron-on strips of veneer banding provide a less noticeable remedy; however, the heat-activated glue sometimes weakens over the long haul, and you can't add an edge treatment, such as a round-over.
Looking for a better way to treat plywood edges (and those of other hardwood-veneer sheet goods, such as MDF), we found three bits or bit sets designed specifically to improve -- though not necessarily make easier -- the task of edge-banding 3/4" plywood. (Similar bits also work with 1/2" plywood.) After testing them in our shop, we're ready to reveal the pros and cons of each.
Burgess Edge Set
The Burgess Edge Set consists of two mating cutters -- one to machine a curved recess in the edge of the plywood, and another to shape the solid-wood banding that fits into that recess. To use them, cut your plywood panel to finished size, and then rout the recess. Next, rout the bullnose on a blank of the same thickness as your panel, and glue it into the recess. Finally, trim your panel to finished size, removing the excess banding. The banding nests between the outer veneers of the plywood, virtually eliminating any sign of a joint line.
- The banding looks as seamless as iron-on veneer tape, but its 1/4" thickness and larger glue surface area make it more durable than tape.
- If you prefer a routed edge, you can leave the banding, say, 1/8" proud of the veneer, and then rout a 1/8" round-over.
- Banding can't slip up or down on the edge of the plywood during glueup and clamping.
- It's the only product of those we tested that can be used effectively in a handheld router.
- Tolerances are so tight with this system that minor thickness variances in a single sheet of plywood can leave veneer near the edge fragile and prone to chipping.
- We had to shim the bits to get them to match both the plywood thickness and each other. Several test cuts were needed to get the correct thickness and cutting height, like a rail-and-stile router-bit set.
- Because of the captured nature of the banding, we found it difficult to measure for mitered corners when wrapping all four edges of a panel.
- Despite the manufacturer's suggestion that the banding thickness needn't match the plywood thickness, we found it easier to machine the banding when the thicknesses matched exactly.
- High cost.
- Both bits have bearings to guide the workpiece, but we achieved our best results by setting our router-table fence flush with those bearings.
- Also available for use with 1/2" plywood, and a shaper.
Edge V-groove bits
Think of this bit set as a low-tech, lower-priced version of the Burgess Edge Set. Instead of a cove and bullnose, however, these bits create a V-shape groove and solid-wood piece of banding to match.
- Same "pros" as Burgess Edge Set.
- No shimming is needed to adjust for differences in plywood thickness.
- The V-groove leaves a little more plywood supporting the veneer -- and a little more gluing surface -- than the cove made by the Burgess bit.
- Works equally well with 1/2" and 3/4" plywood.
- Same "cons" as Burgess Edge set, except for the cost.
- These bits are less forgiving than the Burgess set. When trimming the panel to its final size with the banding installed, overcutting it by a mere 1/64" reveals the plys and ruins the panel.
Unlike the other edge-banding bit sets we looked at, the barrelshaped PlyPrep bit doesn't create male and female workpieces. Instead, it cuts a shallow cove into the edge of a plywood panel. Because of the cove, you can "clamp" the banding with mere masking tape: Glue causes the panel's interior plys to swell to meet the banding, creating a tight-fitting joint.
To use the bit, set it up in your router table so the groove in the center of the bit aligns with the center ply of the plywood. Then, adjust your fence so the top edge of the plywood just intersects the cutter. This allows the bit to remove little (if any) of the plywood's outer veneers. Solid-wood banding can now be glued to the freshly cut edge.
- Because the plys swell to meet the banding, we found we could successfully "clamp" the banding onto the plywood with only masking tape, yet still achieve a tight seam between the banding and plywood.
- Fast setup: You prepare the joints with one bit -- no bit changes or fussy height adjustments needed.
- You can rout an edge treatment, such as a chamfer, bullnose, or round-over, on the solid-wood banding.
- The dimensions of the plywood panel equal the "short" (heel-to-heel) dimensions of the banding for making mitered corners when banding all four edges.
- Color and grain differences between the plywood veneer and the solidwood banding can detract from the seamless look.
- Panels must be cut undersize to account for the thickness of the banding.
- If you don't center the bit properly on the plywood's thickness, the bit may remove too much material at the top or bottom edge, causing your banding to tilt slightly up or down.
- Not available for 1/2" plywood.
If you're looking for a fast, clampless way to band panels, the PlyPrep bit does the job, and for not a lot of money. It's also the best option for panels that you want to wrap completely in banding and show no end grain. Gotta have that seamless look? Then opt for a set of Edge V-groove bits. Remember, though, that these bits work best on shelving and other workpieces where you want banding on only one edge or two opposite edges because mitering corners is a hit-or-miss process.
©Copyright Meredith Corporation 2005