Drywall corners are tricky to tape after you have done renovations or repaired your dry walls. Before you begin taping your drywall corners, finish all the renovation work on the drywalls. The key to a perfect finish is patience, do not get agitated if your tape bundles up or is uneven, remove it and try again.
Step 1 - Measure the Length of the Corner
Measure the inner corner lengths of the corners you plan to tape and seal. Note down the measurements.
Step 2 - Measure, Cut and Fold the Tape
Now cut off tape a little more in length than your measurements and fold it in the middle. It is better to use paper dry wall tape rather than going for fiber glass mesh or other such materials.
Step 3 - Filling out the Corners
Before taping the corners you will need to fill out the corner with caulking material (readymade joint compound) using the joint knife. Use the knife to evenly apply the compound without lumps. Make sure you apply it to both walls and the corner.
Step 4 - Applying the Tape
Apply the folded tape with each folded end on adjacent wall and the fold crease in the middle settling in the corner. Start from the roof, working your way down. Cut off the extra tape once you are done. Use the joint knife to seal the tape edges, being careful as to not rip the tape in the process. If you roll up the tape and unroll as you work your way down the corner it will make the application a whole lot easier.
Step 5 - Setting the Edges of the Tape
To perfectly set the edges apply some more of the compound on the edges, skim away extra with the joint knife and leave to dry. Make sure the tape is perfectly secured. You might have to use a smaller mud knife for this. Keep the edges of the knife clean by rubbing it against the edge of the pan; this will give a better finished look.
Step 6 - Reapplying the Spackling Compound
Once it has dried, reapply another coat of the compound covering the tape, skimming it all the while, so that there are no lumps in the compound. Let it dry overnight and repeat again on both sides of the wall, leave to dry. Do not use thick coats, otherwise it will cause the compound to later crack and chip.
Step 7 - Finishing the Corner and Sanding
Once the compound has set, use your finger to apply some more of the compound in the corner, tracing the line of the corner to fill it out giving the corners a rounded look. Once the entire compound has dried, use a medium grit sand paper to sand away excess compound and smooth out any lumps and irregularities. Finish with paint or wall paper, whichever goes with the furnishings of your room.