"Jennifer" wrote

I recently installed a nice bathroom sink vanity that is constructed
with particle board. To protect the board and guard against
under-the-sink damage from leaks, mold, bathroom humidity, etc, I am
thinking of using (oil based) polyurethane on the interior, which is not
painted. Is this a good idea? Are there reasons why this should not be
done?

Much better would be to buy a piece of vinyl flooring ... they sell it
in small rolls for just this purpose ... and line the bottom. I have my
kitchen sink lined with that, and I have a basin under the pipes. Taking
no chances. I've never bothered because I have stuff on top of the
flooring material, but you might want to staple down the corners to
keep it flat.

nancy