How to Fix a Busted Outside Drywall Corner

Assess the damage to the corner nearest the gouge and check for cracks or dings above and below the gouge.

Examine the corner itself to determine whether you can see a thin metal sheath fitted onto the outside of the corner. If you see a metal sheath, peel away the damaged drywall. Brush dust away from the area so that you have a clean surface to work with.

Apply drywall tape or netting over the gouge. Make sure the netting or drywall tape extends at least an inch past the edges of the gouge. If the gouge is on the center of the corner, wrap the drywall tape or mesh netting horizontally over the gouge, with ends of the tape extending onto each sides of the wall.

Apply drywall joint compound to the repair area with a wide putty blade. Start at the corner and firmly sweep the putty knife with compound on it to the corner edge and away from the corner. Feather the wall joint compound 3 to 4 inches from the corner toward the broad surface of the wall.

Repeat the process in the other direction, ensuring that the corner is well covered and putty feathers outward toward the wall itself. Try to keep this layer as flat and uniform as possible.

Allow the compound to dry, and then apply another coat. Allow this coat to dry as well. Wet joint compound looks a dark gray color, but turns white as it dries.

Feel the compound over the repair to check for dryness. The patched area should feel hard and firm to the touch. Use your fingers to feel for ridges or bumps in the repaired area. Sand the repaired area with a sanding block high-grit sandpaper, such as 120 to 150 grit. A sanding block will ensure a smooth, flat surface. Use light back-and-forth motion with the sanding block, then circular motions over the flat side of each corner edge.

Pass the sanding block vertically up and down along the corner itself, shaping the corner to match original section of the corner above and below the repair.

Paint over the repaired area.