Q: I can do a decent job at taping and mudding the flat seams of drywall, but still have a little trouble at the inside corners. For one thing, I tend to gouge the mud on either side of the tape with my knife. Also, I generally apply the mud from the top down, and then from the bottom up, but it’s pretty ugly where the mud meets in the middle. Any advice on how to avoid this?
A: Try applying skim coat to one side of the corner. Crease the tape and apply one side to the skim coat. Use your taping knife to squeeze out excess beneath the tape and then apply a thin coat on top of that side to set it. Allow the first side to dry overnight. On the next day, mud the second side of the creased corner tape in the same manner. This will help prevent gouging and help prevent pulling one side of the tape out of the wet mud when you’re setting the opposite side. Once both sides of the tape have dried, you can use an angled corner tool to finish mudding.
As far as applying the mud, it’s best to start at the top and work down to a comfortable point, then start again at the bottom and come up. You’ll get a minor imperfection where the two strokes intersect but if you minimize the imperfection you can easily sand it out later.