Tools for Drywall on an Inside Corner

Drywall Knife

• A 6-inch drywall knife is used for scooping the drywall joint compound, applying it to the inside corner and also for spreading it around. For successive layers of joint compound, you will use larger drywall knives, such as 10- and 12-inch ones. For the inside corner, you will use the knife to push the drywall tape firmly into the corner and to smooth it out. The blade of the knife is generally flexible steel, with a handle that is often made of rubber. A specially-designed inside corner knife allows you to embed the tape into the joint compound and smooth the joint compound on both sides of the inside corner simultaneously.

Corner Trowel

• A corner trowel has a handle with a metal blade that is bent at an angle, almost resembling an open book. The blade often flexes to different angles for easier use on inside corners. The trowel, like the drywall knife, has dual uses, such as embedding the drywall tape and also smoothing out the final layer of drywall joint compound to the taped corners. A flatter trowel that is only slightly curved can be used to hold the tape in place while embedding the tape with the drywall knife.

Drywall Tape

• Drywall tape is traditionally made of paper. Many installers also use a self-stick, fiberglass mesh tape, but many prefer paper tape for corners. Either way, the tape is used to cover the joints of the inside corner, pressed into a bed of joint compound. Paper tape is folded in half before being applied, then spread out and worked smooth from top to bottom with the drywall knife. The paper tape usually has a factory crease down the middle of it to make folding it in half easier. This is one of the reasons professionals prefer it over the mesh tape, along with the opinion that paper tape is stronger.

Sandpaper

• Once the joint compound completely dries, imperfections need to be smoothed out with sandpaper. Use 150-grit sandpaper wrapped around a wood block and sand lightly so that you do not sand off too much of the compound and sand into the drywall tape. To reach higher areas on the wall, use a step ladder or a pole sander. A pole sander has the sandpaper attached to the end of a pole.