Do not use any solvents such as alcohol, acetone, citrus based cleaner, or any product that is water based. Don’t use goo gone, tar remover, lighter fluid, or gasoline. Don’t use ant product with ammonia or any formulation of glass cleaner. Do not use simple green, purple power, 409, or “Fantastic” cleaner. Don’t use any automotive cleaning products made for enamel paint. These will damage or strip the shellac and can remove the gold foil decal, leaving the decal with a “silvered” appearance. Shellac will absorb water and turn white (remember the white rings left in you Mom’s table finish when you left a glass of water on the surface? That’s how they got there and they are difficult to remove, if at all.
I have read that kerosene can be used, but out of an abundance of caution, I won’t use it… My concern is that it can seep between the shellac and the lacquer paint underneath. It’s just a concern… I have not experienced it, but because I can see how it could happen, and because there are better alternatives for cleaning, I’m not going to experiment with it.
The safest method to clean and restore a nice shine on these machines is to use sewing machine oil. Applied to the surface and gently rubbed into the finish with your finger or soft cloth with gentle pressure, will do a great job in renewing the finish without damaging it. Shellac is oil based, and it won’t be damaged by this method. This should always be the first step in cleaning these machines. The results are good, and remember that once you apply any cleaning product, if it damages the finish or decals, it can’t be undone.
Professionally Restored Vintage Fine Quality Sewing Machines 