Tips on Varnishing an Interior Door

Preparing the Surface

• Varnish will not stick well to the interior paints that are found on doors. You also won't get that natural-wood look with varnish if the door's surface isn't prepared properly. If there's an existing layer of paint, stain or other varnish on the surface of the door, it must be sanded off. Varnish doesn't cover up the slight imperfections that can be hidden with paint, so fill in any cracks or holes you don't want showing and sand them down. Wipe the door completely clean of all debris prior to adding the varnish.

Bubbles

• Interior doors are prominent parts of your home's decor, but applying varnish that has bubbles in it will create unsightly raised and multicolored circles throughout the surface of your doors. Varnish must be shaken or stirred vigorously to get the most even application possible, but once you've shaken or stirred it, you must wait for the bubbles to dissipate. It isn't unusual for this to take hours, and it could delay your varnish application until the next day.

Layers

• The best way to apply varnish on a door is in several thin layers, according to Realtor.com. Allow the first layer to cure overnight, then use a very fine sandpaper to remove any imperfections. Wipe the door down and then apply another coat. Continue this until you have the color and look you want. It isn't unusual to have to apply 4 or 5 coats of varnish to get the desired result.

Door Frame

• When varnish is applied to a door, it can create a thick, sticky surface, and the varnish may become more tactile in the hotter and more humid months, then solidify in the cooler months. Your door will need at least one-eighth inch of clearance between it and the frame if you're going to be able to use it after applying varnish. Since this is an interior door, you can leave more of a gap between the door and the frame than you could with an exterior door. Prior to applying varnish to an interior door, make sure that you have a uniform and sufficient gap to allow the door to work properly.