Once your sheet rock has been installed, or hung, you will need to finish it. Sheet rock mud is used to finish sheet rock. The mud will cover and conceal all of the seams between pieces of sheet rock, and all of the indents where screws were inserted to hold the sheet rock to the wall.
Step 1: Use sheet rock tape to cover all of the seams between pieces of sheet rock. It is best to use self adhesive sheet rock tape as it is the easiest type of tape to apply. To apply the tape start at the top or bottom of the seam, press the end of the tape to the wall, roll the tape down the seam, and rub it gently so it adheres. Use a utility knife to cut the tape at the end of the seam. If you are using standard non-adhesive tape you will need to mud over it as you are applying it, as shown in the picture.
Step 2: Fill a mud pan full of sheet rock mud. Use a mud knife to smooth a thin layer of the mud over all of the seams that you have taped. Run the knife over each seam vertically. The mud will cover the sheet rock tape. If you see any bumps or ridges of mud along the seams after you have applied the mud go over the seam again without mud on the sheet rock knife to remove the bumps and ridges before they dry.
Step 3: Use the sheet rock knife and the mud to cover all indents where screws were inserted. Screw indents do not need to be taped. There will be several indents. Mud each indent individually. This may take a little time but it is worth it.
Step 4: Allow the first layer of mud on the seams and screw indents to dry for at least four hours. Once the mud is dry it will be bright white. When the mud is dry use an electric handheld sander, or a pole sander, to sand each seam and indent where mud has been applied.
Step 5: Wipe the walls down using a dry cloth. Wiping the walls down will remove the dust that was created from sanding.
Step 6: Apply a second coat of mud over all of the seams, and over all of the screw indents. The second coat of mud provides additional coverage. The seams and indents will not be visible at all once the second coat of mud is dry and has been sanded. The walls will be flawless and perfectly smooth.
Step 7: Allow the second coat of mud to dry for another four to six hours, then sand well. Wipe the walls down again using a clean dry cloth. Your sheet rock is finished and is now ready for primer and paint.