Flush Trim Router Jig

Illustration by James Provost

When using a router to flush trim the edge banding on sheet stock, you have two options: balance a router equipped with a flush trim bit and fence on the narrow edge of the plywood, or run the router on the face side of the plywood using this jig and a mortising bit. We think you’ll find this jig much more stable than trying to balance the router on the edge. The extended length and extra handle make it extremely steady and easy to control. This version is sized to fit a Porter Cable 690 router ( deltaportercable.com ) so you will have to adjust the width to suit the router that you will be using.• Cut all the pieces for the jig to dimension. Install a ¼" spiral bit in your router table, and adjust the fence to rout a 1" slot, ¾" in from each edge of the router mounting plate (A) starting ⅜" at one end. Cut one slot with the material on one side of the bit and then flip it over to cut the slot on the opposite edge. Mark the position of the fence before removing it, and then switch to a ½" bottom cutting bit. Replace and run the piece through again to create a recess for the screw head.• Carefully line up the base (B) with the mounting plate and glue them together. If you have an air nailer, shoot a couple of brads to help keep them aligned. Clamp the two pieces and set aside to dry. Glue together the two pieces for the fence (C). Line these up and clamp them in your bench vise to dry.• Remove the base plate from your router and position it on top of the router mounting plate and mark the location of the mounting holes and the center of the bit opening. Drill out clearance holes for the router mounting screws and counterbore the holes from below. Use a 1" Forstner bit to drill the router bit clearance hole.• Place the glued-up fence block under the jig, mark the location of the bolt holes, and drill them out using a 5⁄16" bit.• Place the guide plate (D) between the fence (C) and a sacrificial block of wood, line everything up so the bottom edge is even and clamp this with your bench vise. Use the existing holes as a guide to drill the holes through the guide plate.• Shape the front edge of the guide plate on a disk sander to give the two corners a softer rounded profile that will easily ride over small obstructions, like saw dust.• Sand all pieces and give them a coat of paste wax to reduce friction.• Assemble the pieces with the wing nuts facing down.• Trace out the shape of a handle (E); a plane handle serves as a good template. Cut it out on a bandsaw, and then sand the surfaces with a drum sander and round the edges over with a ¼" round over bit. Attach the handle to the far end of the jig to provide a stable handhold to control and counterbalance the router.