I've attached a sheet of ply to the base of my aquarium stand. The idea is that my sump will sit on the ply and the surrounding 2x4 base will then act as a tray in case of spillages/overflows from my sump. To ensure this tray area is totally watertight will it be sufficient to run a bead of aquarium sealant where the 2x4s and the ply meet? Then i'll paint it all with waterproof paint. I know that sealant sticks to glass like s**t to a blanket but how about wood?