This story covers techniques for handling two- and three-way corner bead application
You'll find two-way corners at doorways without wood trim and the inside corners of soffits. The outside corner of a soffit is a typical location for a three-way corner.
No matter where they're located, it's a good idea to invest some extra care into the creation of these corners. A sloppy installation will raise the degree of difficulty in applying the drywall compound and can result in a misshapen corner that acts like a magnet for a visitor's eyes. But a carefully fitted corner will make mudding an easy task, and you'll be rewarded with crisp lines that generate compliments for your workmanship.
Bullnose corners are even easier than square profiles because you can purchase vinyl and metal corner caps. You fit the caps first, then simply make square cuts at the ends of straight runs of bullnose stock to butt them into the preformed corners. It's a good idea to purchase the corners and bullnose stock from a single supplier to ensure that the radii are equal.
Project time depends upon the amount of bead that's required and the number of corners that must be fitted. Plan on 15 minutes for the first bullnose strip.
Tape measure, tin snips, file
Accurate measuring and cutting
Drywall is hung.
Corner beads; preformed corners for bullnose application, ringshank drywall nails
If you build a soffit, you may have to deal with a three-way corner. After you cover the framing with drywall, double-miter a piece of corner bead for the long horizontal run, and nail it in place. Cut a double miter on another piece of bead, and then square-cut it to length for the other horizontal run. Match the tips of the two pieces as closely as possible.
For the third piece, double-miter another piece for the vertical corner. Again, carefully fit its tip against the two that are already in position. After the third piece is in place, you may need to file the tips to correct any small misalignment. Finally, take a few file strokes across the point, slightly blunting it so that it's not dangerously sharp.
Bullnose corners can require substantial amounts of drywall compound to blend the bead into the walls. Avoid problems by choosing setting-type compound for the first coat or two, and resist the urge to apply it too thickly. Instead of saving time, a too-heavy application strategy can backfire by cracking. To ensure that the crack won't telegraph through the final application, cover it with fiberglass or paper tape before applying the next coat of compound.