Applying The First Coat In Corners
1 APPLY A THIN LAYER OF JOINT COMPOUND to both sides of the inside corner with the 6-inch knife.
2 FOLD A STRIP OF DRYWALL PAPER TAPE IN HALF BY PINCHING THE STRIP and pulling it between your thumb and forefinger. Position the end of the folded tape strip at the top of the corner joint. Press the tape into the wet compound about 12 inches.
3 START AT THE TOP OF THE ROOM AND DRAW THE KNIFE ALONG ONE OF THE WALLS, smoothing the tape. Repeat on the other wall. Move the knife a couple of inches away from the corner and pull from ceiling to floor, removing the excess compound left by the first pass.
Taping butt joints - Butt joints occur where the two narrow ends of a sheet meet. Unlike the long side, these ends aren't beveled to make taping easier. Open up the joints by cutting a 45-degree, 1/8-inch-deep bevel in the end of each panel with a utility knife. Fill the notch with compound, leaving a bed about 1/8 inch thick on the surface. Press the tape into the bed as you would with a tapered seam, and draw a knife along it to smooth the tape.
Applying The Second Coat
1 LET THE FIRST COAT DRY THOROUGHLY. Apply a second coat of compound over the screws. Coat the outside corners and seams as before, using an 8-inch knife. Feather the edges so that they are about 2 inches wider than those of the first coat. Feather the edges of any butt seams so that they are about 4 inches beyond those of the first coat.
2 AT THIS POINT, FINISH THE INSIDE CORNERS ONE WALL AT A TIME. Apply a coat of compound on one wall, feathering it out 2 inches beyond the first coat. Let the compound dry, then repeat on the second wall.
Applying And Smoothing The Third Coat
1 APPLY A THIRD COAT (THINNED WITH WATER TO THE CONSISTENCY OF MAYONNAISE) TO THE SCREW HOLES, SEAMS, AND OUTSIDE CORNERS with a 12-inch knife, feathering the edges 2 inches beyond the second coat.
2 ONCE THE FINAL COAT HAS DRIED, SMOOTH OUT ANY IRREGULARITIES WITH A DAMP SPONGE. This works just as well as sanding— without creating dust.
Sanding high areas - Ceilings and some high areas may be easier to reach with a pole sander. Put 200-grit sanding mesh on the pad and run it back and forth along the seams. Sanding mesh is a piece of screen coated with abrasives; it won't clog when you sand with it.