You can get perfectly tight joints and smooth, clean, professional results when installing trim, even on bad walls. This article demonstrates seven tricks that the pros use to solve the most common problems—like closing gaps along wavy walls and making crisp joints at corners that aren't square.
If there's a gap, sometimes a drywall screw is the perfect adjustable shim. For example, when you're applying baseboard, the drywall at floor level often tapers back, making it hard to get the baseboard corners to line up well. A couple of screws driven into the bottom of the wall will quickly solve the problem, and do it a lot faster than filling the area with joint compound.
You can close a small miter gap by rubbing it with a screwdriver shank or any hard, smooth tool. We used the end of a utility knife. That crushes the wood fibers inward to make the gap disappear. Even professional woodworkers sometimes resort to this crude trick.
the secret for a glove-tight fit for trim corners is a coped joint. with this technique you can even make complex crown moldings fit without leaving gaps. because inside corners are rarely square, simply butting two mitered pieces into the corner almost always looks lousy. the only foolproof method for great-looking inside corners is cutting a coped joint. this age-old carpenter