Feather out the edges of the swaths well with the knife for a smooth look. Step 10: Apply a third coat of drywall mud. Apply a third very thin coat of mud after the second coat dries. Use the 10 ...

drywall knife across all the fasteners ... so on warm days mix the compound with cool water. Dump the leftover mud in a bucket, not down the sink, where it can harden and clog the drain.