Doors that bind or will not close properly are common problems. People usually try to plane off the edge. But frequently the solution is on the hinge side.
A hinge can often work loose, binding the door against the frame. Before trying to trim the door, open it and examine the hinges. Test each screw by tightening it with a screwdriver. That may be difficult on older painted doors. Accumulated layers of paint can obscure the screw slots.To clear the slots, rush on a small amount of paint remover. Allow a few minutes for the remover to loosen the paint. Then scrape the slots with a knife or a paper clip.
There are times when the screws cannot be tightened, because the wood is worn and the screw holes are enlarged. In that case, plug the holes with short lengths of wood dowel dipped in carpenters' glue. First remove the screws. Then swing the hinge leaves out of the way.
You will probably be able to make the repair without removing the door. But before unscrewing the hinge, swing the door open and prop it up by wedging a magazine under the outside corner. That will support the door when the hinge is released from the frame.
Cut the dowel to length, 1 to 1 1/2 inches, before tapping it in place. The holes can also be filled with wood toothpicks or even a golf tee. With those materials it is best to trim them with a utility knife after they have been glued in place. Let the glue dry. Drill pilot holes, and replace the screws.
If the door binds and the hinges are secure, the problem may be with the hinge mounts. Open and close the door to find the problem. Look for signs of abrasion on the edge of the door and for uneven gaps between the jamb and the door. If the door binds on the hinge side, the hinges may be too deep. If the door binds on the knob side, the hinges are too shallow. Resetting the hinges can correct those problems.
Hinges that are too deep can be corrected with shims between the hinge leaf and the mortise, the recess in the wood for the hinge leaf. Shimming can close gaps between the door and the frame. It can also realign a sagging door. If the door sticks at one point like the top corner, the problem may be caused a deep lower hinge. The bottom is pulled inward when the door closes. That can be corrected by inserting a shim in the lower hinge.
Shimming is not practical when there is not enough clearance between the knob edge and the jamb. There it is better to set the hinge deeper by cutting into the mortise.
Close the door and wedge it to keep it stable as you work. Next remove the hinge pins from the hinges. Most modern hinges have a hole on the underside. You can insert an 8-d nail in this hole and tap out the pin with a hammer. On hinges without a bottom opening, position a screwdriver under the head of the pin and push it upward. Loosen the bottom hinge first, and then the top one. Before replacing the hinge pins clean them with steel wool and coat them with light oil.
Just a sharp chisel is needed to deepen a mortise. Start by holding the chisel perpendicular to the surface and tapping around the perimeter of the mortise. With the chisel still in the vertical position, tap a series of light cuts across the surface of the mortise. Now lower the chisel to a horizontal position and remove the surplus wood by pushing the chisel across the grain.
Sometimes the hinges are fine, yet the door still sticks. The door may have expanded or warped, and it should be sanded or planed. It may be possible to do that without removing the door if the distortion is slight. If you have to plane the entire length of the door it will be necessary to take it down.
When planing the entire door, work on the hinge side. If you plane the lock side you will have to remove and reposition the lock, a difficult job at best. After planing, seal the raw edges with paint or varnish.