Yes, as long as the previous finish is not lacquer or shellac. Be sure to test the selected colour on a hidden spot to see how it will look over the original finish. To prepare the surface, make sure that the finish is clean and has had all wax and polish removed. Then lightly sand with #180 or #220 sandpaper.
Then thaw meat, add seasoning and press into strips or sticks, and place on trays to dry. Depending on how thick meat is cut, how heavily dryer is loaded, and the humidity, jerky takes from 4 to 15 hours to dry.
Lay your jerky slices out in a single layer with no overlap in your dehydrator. Set your dehydrator to 155 degrees. Dry at 155-degrees (this is typically the highest setting on a dehydrator with a heater unit) for 4-6 hours, until the jerky is fully dry and dark throughout and bends to a tear without beads of moisture.