Painting - water-based poly wainscoating

Picture water-based polyurethane-coated wainscoating in a bathroom. Homeowner says she has to keep doing it because over the sink, where towels hang, etc.(basically everywhere water contact is an issue) the urethane peels. I need to know if anyone has any info. on re-doing this wainscoating with an oil-based polyurethane; does it need to be sanded/scuffed, etc. any pointers will be hugely appreciated!

Oil base poly will offer better protection BUT it will change the look of the wood. Oil base will darken raw wood and amber with time. This may not be a big deal BUT if any of the wood is raw it will appear to be different color than the waterbase coated wood.

You should lightly sand the wood before application. If you have any raw spots, I'd coat them with some waterbase poly [let dry and sand lightly] before applying the oil base.

Oil base poly isn't a good substiture for a backsplash - if the sink counter doesn't have one.

Thanks for the input, marksr. I believe the wainscoating is all natural wood with only the water-based poly over it, which is peeling heavily in the previously-mentioned areas. It is an old sink, mounted directly to the wall (no vanity, countertop, etc.). So, w.b. poly the peeled spots, lightly sand entire area, then okay to oil-based poly over all? I know it's not ideal, but they want it re- urethaned, if possible, with something that won't peel as the w.b. stuff has. Thanks again.

So, w.b. poly the peeled spots, lightly sand entire area, then okay to oil-based poly over all? .

Yep, that's the way I'd do it ;)

Thanks again!! That's what I thought.