Drywall corners may be the most difficult aspect of finishing drywall. Drywall corners are made by using metal corner beads. These are placed over the corner, nailed in place, and then covered with tape and drywall. As a home settles, the drywall corners can crack. The article below will explain how to repair chipped drywall corners.
Clear the Damage
You want to start with a clean surface. Use the utility knife to scrape the damaged drywall from the corners. You want to scrape down to the metal or the mesh tape underneath.
Cut a piece of the mesh tape to fit the area to be repaired. Press it in place over the metal or plastic beading. The tape helps mud stick to the drywall corners.
Apply the drywall mud to the damaged drywall corners using the putty knife. Put on enough to fill the damage, and then spread it out. Feather the edges to the surrounding wall. Sand it flat, and apply a second layer, expanding this layer past the first. Sand again.
You can now paint the drywall corners to match the rest of the wall.