Can you use epoxy over stained wood?
Yes, though what you have to do first depends on the type of stain.
Water-based or alcohol-based stain: these are ideal. They dry fast, and the epoxy can go over them in about 24 hours with no polyurethane needed. If you haven't stained yet, this is the route to take.
Oil-based stain such as Minwax: UltraClear Bar & Table Top Epoxy does not adhere to oil-based stain; it repels from it, and waiting for the stain to dry doesn't change that. Pour straight over an oil-based stain and you risk the epoxy not sticking and peeling off months later. This applies even to oil-based stains labeled fast drying. If the wood is already stained with an oil-based product, seal it first:
- Apply a minimum of 3 coats of clear oil-based polyurethane over the stain. Coat every bit of stained wood; the epoxy must never touch bare oil-based stain.
- Wait at least 24 hours after the last poly coat.
- Brush on a seal coat of Bar & Table Top Epoxy. Poly alone doesn't seal the wood well enough to stop air bubbles, so don't skip the seal coat.
- Pour the flood coat 4 to 6 hours after the seal coat.
If the epoxy pools up or pushes away from any area during the pour, that spot didn't get enough poly. The epoxy bonds to oil-based polyurethane, just not to oil-based stain.
Pouring UltraClear Deep Pour Epoxy over oil-stained wood? Same rule: 3 coats of oil-based poly, then a seal coat of Bar & Table Top Epoxy before the Deep Pour to keep air bubbles out. See River tables: How to use Table Top Epoxy with Deep Pour Epoxy.
This is general advice; some niche stain products may behave differently from the average stain of their type, so test a small area first if you're unsure.