How to install paper-faced corner bead in four steps

Before the first bead goes on

Check that the corner is plumb and that the board edges are sound. A bead will straighten a wavy corner by a few millimetres, not by ten. If the framing is out, fix the framing.

Mix the compound to a consistency that holds a ridge on the knife but still wets the paper — closer to mayonnaise than to toothpaste. Setting-type compound gives a longer working window on a hot site.

Step 1 — snap a line

Mark the corner line in both directions so the bead nose lands on the same plane as the finished wall. On a long run, check at the top, middle and bottom; a corner can be straight and still lean.

Step 2 — bed the wings

Spread compound across the full wing width — not a bead of dabs. For a partial bed, spot at 150–200 mm centres and always fully bed the last 300 mm at each end, where the corner takes the most abuse.

Step 3 — press and squeeze

Press the bead home from the nose outwards with a wide knife, then run the knife along each wing to squeeze out the excess. The wing should sit flat, with compound showing through every perforation. Wipe the squeeze-out back into the pan — do not leave a ridge to sand later.

Step 4 — skim, dry, sand

Skim tight over the wings, 150–200 mm wide. Let it set fully, then apply a second, wider coat feathered to about 250 mm. Sand lightly with 150–180 grit, check under a raking light, and spot-fill anything that still shows before primer.

The two mistakes

• Dry bed. A wing bedded on dabs looks fine wet and rings hollow two weeks later. If it sounds hollow, cut it out.
• Bending 90° to 135°. The paper wrinkles and lifts off the core. Use softline for obtuse angles.