Finishing Drywall Joints: Tape Coat
Taping Before starting the taping process, make sure corner bead is installed on all outside corners.
Also make sure that all the fastener heads are sunk below the surface of the drywall. You can check them by running a taping knife over the drywall. If you hear a "click" you've got a nail or screw that needs to be sunk deeper. Just give the nails an extra tap, or give the screws a twist with a phillips-head screwdriver.
Professional tapers sometimes notch out the butt joints so they have more space for the first pass of joint compound. This helps eliminate the "hump" that you might get when taping these joints.
The entire finishing process is about a 4-
step, 4-day process. The first step is called the "tape
coat." This is when you apply joint compound to the seams and embed paper joint tape in it.
First Pass of Tape Coat
Mix up your joint compound. If you're working with pre-mixed compound, don't mix it too much, this can work air into the mixture and then you can get little bubbles and craters on the surface of the wall.
Starting on the ceiling, first spread out a layer of "mud", as the professionals call it, over the joints. For this first coat use a 5" or 6" taping knife.
Be generous with the mud at this point. Spread out more than you need to fill the seam.
TIP: The trick to spreading out mud is to hold the knife almost vertical to the drywall when it's full of mud, and press it flatter as you move along the joint. This spreads the mud evenly over the whole stroke of the knife.
Embedding Joint Tape
For the second pass, lay a piece of joint tape over the center of the joint. Press it lightly with your hand--just to make it stick for now.
Then go back and flatten the tape into the mud, working from the center of the joint out to the sides.
You can use pretty firm pressure with this stroke. You'll end up scraping off some of the excess mud, just leave some mud under the tape.
TIP: As you tape, keep your knife clean. Constantly scrape it off the side of the pan. Mud that stays on your knife will dry out faster.
The last step for the tape coat is to spread a very thin layer of mud out on top of the tape.
This requires a gentle touch. The layer should be thin enough that the tape is still visible through the mud.
Don't worry too much about a few grooves and streaks on the surface for now. There'll be more coats to smooth it out later.