Replacing a window opening made of MDF, with plywood.

Replacing a ledge to a window opening made of MDF with plywood. The ledge is also the top of a box made to encase a water heater in the master bedroom. The original surface made of MDF, took on some water damage and MDF does not repel moisture at all. It absorbs any moisture and expands rendering it useless after. I replaced the MDF with plywood, which I then painted and sealed with a thick coat of clear semi-gloss varnish to protect it and give it a nice shiny tint.

Progression images.