Fixing the Fit

Sometimes, molding installations speed along at a rapid pace because the walls are straight and the corners are square. But other times, progress is maddeningly slow because of out-of-square corners, bulging drywall, and wavy walls.

Painter's caulk is one solution to the problem of a poor fit between the wall and the wood, but it's not the only recourse you have. In fact, your caulking gun should be your last weapon -- not the first.

By checking the walls prior to installation, you can identify and correct problem areas. Shaving down an offending hump of drywall is one solution and it's great for fixing big bulges. If the problem area is smaller, however, knock it flat with a block of plywood and a hammer. If you notice a gap between the picture-frame casing of a window and the wall, resist the urge to push the joint flush against the wall. Doing so will open the miter, creating a problem worse than the one you had before.

The scribing technique is a great way to fit a cabinet seamlessly against a wall. But a thin strip of molding is a fast and efficient fix. Sometimes you need a completely different approach, as when you're installing crown molding against a wavy wall. In this case, you build the wall out to meet the molding. It's not as difficult as it sounds.

If your check of the wall uncovers some small waves or bulges, you can sometimes tap them out of existence. Draw a light pencil line to identify the outer edge of the casing, and smack offending areas with a plywood block and hammer. Don't get carried away or you could whack the wall or jamb out of alignment.

If a mitered casing gaps away from the wall, pushing it would open the joint. Instead, gently insert a glued tapered shim at the top to prevent movement. Let the glue set, then trim the shim flush with a fine-tooth saw. With the casing supported, you can now caulk the joint.

To fit a cabinet's rail against a wall, applying a thin molding strip to the surface is much faster and far less dusty than scribing and cutting the rail. If you have a table saw, you can quickly slice the piece yourself. For safety, install a zero-clearance throat plate in the saw and use a featherboard and push blocks. No table saw? No problem. Simply purchase the strip.

Here's how to build out a wavy wall so that it meets the molding. Make the jig from a piece of scrap molding or 1/2-inch-thick plywood that's about 12 inches long. Cut a notch to match the molding and screed drywall compound along the jig and into the gap. If the wall is exceptionally wavy, lengthen the jig to taper the compound farther down the wall.

After you've exhausted all of the other tricks to disguise a less-than-perfect fit, reach for the painter's caulk. Buy a good-quality product, making absolutely certain that the label says "paintable."