Updated: Jan 12
1) Place mesh tape over the crack.
2) Apply the first of three coats of patch. The first coat should be a light coat. Make sure the edges are as smooth as possible.
3) After the first coat is dry apply the second and third coat of patch.
4) Sand down to a smooth finish. Make sure you don't sand so much that the tape is showing.
5) Prime the area using drywall primer.