How to Fix Chips and Scratches in Tabletops?
Nothing catches the eye like a big old scratch or chip right in the middle of an otherwise beautifully finished wood surface – except, possibly, a failed repair attempt.
When the finish (lacquer or varnish) on a top or dresser is chipped down to the bare wood, what is the best method to repair this damage? Usually these chips are 1/4" wide and 1/2" or 1" long. I have a light-colored mahogany dresser with three small scratches and have tried padding lacquer, but it doesn't level the scratch to the surface. What can I use to bring the surface level and smooth? I have also tried shellac sticks but am not satisfied with the finish these leave or with the color. Can the so-called wax sticks be used for this type of repair, and will the topcoat finish of varnish or lacquer adhere to these waxes?
Michael Dresdner: There are two good techniques for filling chips. The faster one requires more skill, while the simpler one is slow and tedious.
The classic quick method is burn-in stick (sometimes called stick shellac, though modern sticks are of other resin combinations.) Sticks come in a wide range of colors including clear and translucent amber, so with a deft hand and some experience, you can indeed get a very good match. I suspect your dissatisfaction with them could be attributed either to lack of experience (they are not particularly user-friendly, and take quite a bit of practice to get good results) or a lack of access to the proper color assortment.
The other method, called "doping in," is both slower and somewhat easier. Use a small brush to fill the voids, a few drops at a time, with a fast-drying spray lacquer. Use clear, or if color is needed, tinted lacquer. As the lacquer cures, it will shrink substantially. Come back each day and add another drop or two, letting each day's addition cure fully before you continue. Depending on the depth of the chip, this method will take several days or longer. Keep filling until the lacquer sits just slightly proud after it is cured and hard. Sand the area flush to the surrounding finish using 600 grit or finer sandpaper wrapped around a small, stiff block.
No matter which method you use, burn-in stick or doping in, the repair will look much better if you add another topcoat of whatever the finish is to blend the sheen of the repair.
I doubt you will be happy with a wax stick repair. They are opaque, and while they will hide chips in obscure, hard-to-see areas, the repair will be very obvious when viewed head-on, as on a top. In addition, most coatings will not cure over wax stick.