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How to Countersink a Door Hinge

C.L. Rease

Creating a countersink, known as a mortise, allows the hinge to rest below the surface of the door frame and door slab. This allows the door to close without interference from the hinge. The secret to creating a mortise is using a sharp chisel to remove the wood from the area that the hinge is going to mount.

A dull chisel will splinter the wood instead of cutting the wood from the mortised area. This results in unclean edges and wood that will interfere with the installation of the hinge.

  1. Mark the location of the hinge. Place the hinge on the wood surface, at the location mark. Trace the outside of the hinge with the pencil. Make a depth line for the mortise, by sliding the hinge off the wood surface, and setting the top surface of the hinge even with the top surface of the wood.

  2. Place the sharp end of the chisel on the pencil outline of the hinge, with the flat side of the chisel facing away from the mortise. Strike the blunt end of the chisel with the hammer to score the line. Continue to score the entire perimeter of the hinge.

  3. Score across the mortise with the chisel. Start roughly 1/4 of an inch in from the scored outline. Place the chisel perpendicular to the rear side of the hinge. Hit the chisel with the hammer to produce a line that extends from the back to the front of the hinge. Make a similar crosscut ever 1/4 of an inch until you score the entire length of the hinge.

  4. Start the wood removal at either side of the mortise. Hole the chisel, bevel down, at the crosscut closest to the center of the mortise area. Hit the chisel with the hammer. Continue hitting the chisel, as the wood will automatically eject from the area. When you reach the perimeter of the mortise, perform the same procedure to remove the wood from the other half of the mortise.

  5. Place the chisel, bevel side down, against the depth mark that you made in step 1. Tap the rear side of the chisel with the hammer to set the mortise to the proper depth. Run the chisel until you reach the perimeter scored area located at the back of the hinge. Continue the process for the length of the hinge. If the wood does not break from the mortise area, go around the perimeter of the hinge with the hammer and chisel to make the perimeter score deeper.

  6. Set the hinge into the mortise to ensure that the hinge fits within the mortise. Adjust the size and depth of the mortise as needed using the procedures described in the early steps.

Check out this related video from Homesteady on Youtube.