Working with plywood
Of course, marrying fine design with inexpensive building materials is nothing new. Not every project requires exotic woods. Sometimes, as master builder Hendrik Varju points out, plywood does the job.
Iron-on edging is certainly an option, but nothing beats solid-wood edging for longevity, wear resistance and beauty. Solid-wood edging allows me to rout a decorative edge on the panels without exposing the plywood core.
It is vital to decide on routed profiles before choosing the size of the solid-wood edging material to ensure it will be wide enough to handle the profile. For example, if you plan to use a Roman ogee profile with a 3/8″ distance from the router-bit bearing to the outside of the profile, make the edging at least 7/16″ wide, but 1/2″ is better. Your edging will, therefore, be 1/2″ wide x 13/16″ thick. For 3/4″-thick plywood, solid-wood edging should be 13/16″ thick to give you something to trim on both sides of the plywood. Most 3/4″-thick plywood you buy is about 1/32″ undersized, so that gives you an even wider margin for error.
Glue the edging onto the straight, ripped front edges of all your panels, making sure that the edging stands proud of the panel on both sides. A clamping caul across the front of the narrow edging helps distribute the clamping pressure more evenly. I like to use my Pony #50 pipe clamps for this job, although this is a light-duty job that parallel jaw clamps can handle. Even other medium-strength clamps will do nicely.
For edging that is the same thickness as the plywood panels, glue is sufficient, without any dowels, biscuits or other reinforcements. But for edging that is thicker (top to bottom) than the plywood, more reinforcement helps counteract increased leverage should someone bump into the bottom of the edging. Dowels and biscuits will do, although I find that a continuous spline is quick and easy. You can easily rout a 1/4″-wide x 1/2″-deep spline groove into the front edges of your panels with a slot cutter in a handheld router.
The same groove can be routed in the rear side of the edging material, but don’t forget to increase the distance of the groove from the top of the edging so that there is something to trim along the top later. The groove in the edging, which might be something like 11/2″ wide at the glue-up stage, can be routed on a router table if you prefer. But the groove in the plywood edge should be routed with a handheld router so that the base follows the mild curves of the plywood faces.
It’s important to remember that plywood is rarely flat. Many a woodworker has come to realize this problem with sheet goods. However, placing a curved panel on a flat router table is a sure way to rout a spline groove that rises and falls relative to the top of the panel.
Plywood surface materials can vary from high-grade wood veneers to melamine. I use A-1 grade, which is readily available, for fine furniture. The front has A-grade veneers arranged in a flat-sawn, book-matched pattern. The 1-grade back is also high-quality, but will usually have rift-sawn veneers or something just a little less visually appealing.
For less important projects, an A-2 grade might be available, which has a slightly lower-quality back. B-2, which has a lower-quality front as well, could still be adequate for many of your projects. A-4 grade is common for drawer bottoms and cabinet backs, for which only one side is visible.