Answer
Nov 04, 2020 - 04:33 AM
Unknown types breed uncertainty. If the finish on the cabinet was oil-based, worst-case scenario, covering the oil with a water-based product could set off a chemical off-gassing situation, or in a milder case, this water-based finish would flake off once it dried. Water and Oil do not mix. If however, the stain was water-based, then the EXT would work fine over it. EXT is a bit hearty as it is designed for exterior use (the interior version is AFM Safecoat Polyureseal BP) but you could use it in this application. If the finish/stain is super smooth, you may need to gently abrade with a light sanding, not to remove the finish, but to give the surface some teeth for the overcoat to bond to. If you are uncertain, then we have sample sizes so you can test for personal tolerance of off-gassing, and appearance, and a good bond.
