I bought what I call car siding (tongue and grove) for a wall covering. I am lacquering one side but was told I need to seal both sides. Can I just seal the back with shellac? For that matter, could I use leftover paint. No one is going to see the back side.
The carsiding will be 3/4" away from insulated wall as I am putting up 1X4 nailers. The car siding is going on vertically.
Thank you.