We have a finished bathroom vanity in honey oak stain. Can crackle product be applied directly to that and then a latex paint (espresso) over the top of the crackle? Our goal is to bring out some of the honey color between the espresso. Is it necessary to use a base color? Will the crackle adhere to the finish?
You ask some excellent questions here. The answers vary widely. First you need to determine the type finish currently on your cabinets.
This is somewhat difficult with clear finishes. Age of construction and region of your house will get closer to understanding the present finish.
If Lacquer, then you can apply the crackle, but it might or might not adhere for the long term. I am not aware of a clear coating which will guarantee adhesion to lacquer.
If an oil type finish, a good quality waterbourne clear finish should adhere. As for applying a colored coating, try using a finish with some type sheen. The higher the sheen the higher acrylic content. Acrylics adhere better than flats.