Using drywall compounds properly is important to a successful wallboard installation. Drywall compound smooths joints between materials and repairs surface imperfections. The proper installation of drywall compound is simple and easy as long as you leave enough time between applications for the material to dry thoroughly.
Applying the Compound
Use your putty knife to apply a thin layer of the compound to the joints in the wallboard. Apply a layer of joint tape over the compound. Gently press down the tape to remove any bubbles. Give the tape and mud enough time to dry completely.
Smoothing the Compound
Use sandpaper to smooth out the compound and tape area. Use scissors to cut off any pieces of tape that are sticking out from the compound.
Applying Second Layer of Compound
Apply another thin layer of drywall compound over the area, blending it into the surface of the wallboard. Allow the compound to dry completely. Smooth out the dry compound again with your sandpaper. Apply a primer over the area if you plan on finishing the surface with paint.