We have a painted wooden backsplash by our kitchen faucet. Sadly, the wooden is now swelling because of the moisture around. Note that the wood doesn't normally get water on it directly - it appears to just be the water that lands on the countertop below it.
The obvious solution would be to sand it flat and paint with an enamel paint to resist the water. Are there other solutions I should look at?
There is a reason that painted surfaces are generally not used for backsplashes, and you have discovered it.
The standard approach to both counter and backsplash is to have an impervious surface and a seal between them. This is virtually impossible with paint. Occassionaly you will find heavily sealed wood (clear epoxy, marine varnish, etc.) used for either the counter or the backsplash, but they need constant monitoring and repair if scratched or chipped.
You should consider using tile or metal as a backsplash (as suggested by hortstu in his comment). It should also be sealed to the countertop at the base (clear silicone at the bottom edge of the tile/metal).
