In order to refinish an antique sewing machine, it must be cleaned and polished inside and out, lubricated and fixed with working parts. These basic steps, as outlined by Do It Yourself, work for refinishing either hand-crank or treadle sewing machines.
The first step of refinishing and restoring an antique sewing machine is to clean both the interior and exterior of the machine. To clean the interior, one must open the machine through either the panel or the underside by removing the metal plates with a screwdriver. Any loose threads or dust should be removed by using a thin cloth and a pair of tweezers. The refinisher should clean the gears either by dabbing some kerosene oil on a dry cloth or using a spray made for cleaning gears. The outside of the machine also must be cleaned by using a dry or lightly dampened cloth or dry paintbrush to remove dust and dirt.
The second step is to lubricate the working parts of the machine with a little oil. The belt should be checked for cracks and replaced if necessary, along with any other old or non-functioning parts. The exterior of the machine should be cleaned, especially if it has stains. These imperfections can be sanded out. Finally, the refinisher should polish the machine by wiping it down with mineral oil and applying carnauba wax.