How to Make a Flat Board With a Router

You can use a router to flatten boards.

Flatten boards with a router by using the base of the router as a depth gauge. This is done by woodworkers when boards are warped, have inconsistencies or will not fit into a given space because of slight imperfections in thickness. By attaching two blocks to either side at the base of a router, you can control the thickness by passing the router over the board as many times as needed to flatten the imperfection. Set your router to flatten a 15/16-by-2-by-36-inch board down to 3/4-inch in thickness.

Things You'll Need

• 1/2-inch cutter bit
• Plunge router
• Cordless drill
• 1/4-inch drill bit
• 2 wood blocks, 3/4-by-3/4-by-3/4-inches
• 1 3/4-inch screws
• Poplar board, 15/16-by-2-by-36-inches
• Tape measure

Instructions

1. Install a 1/2-inch cutter bit into the router. Turn the router upside down. Unscrew two of the screws across from each other on the router base using a Phillips screwdriver.

2. Drill a hole in the center of the 3/4-inch blocks with the cordless drill and 1/4-inch bit. Place the blocks over the empty screw holes in the router base, align the hole in the block with the hole in the router. Insert two 1 3/4-inch screws into the holes. Tighten the screws with a Phillips screwdriver, securing the blocks to the bottom of the router.

3. Stand the router up. Set the depth of the router bit at 3/4-inch from the bottom of the bit to the top of the table with a tape measure. Lock it down.

4. Lay the poplar board on a worktable. Place the router over the board. One block should be on either side of the board. Turn on the router and push down so that the bit begins to cut into the wood. Lock the router down.

5. Slide the router over the board parallel to the grain. When you have made one pass all the way to the end, move the router over and begin another pass. Continue in this manner until all the passes overlap each other and the board is consistently flat.

Tips & Warnings

• To flatten wider boards, screw a wider piece of plywood to the router base, and then screw the blocks to the outside edges of the plywood.

• Wear safety glasses when working with wood.