We bought an old oak table that came with 2 leaves each 2' x 5' x 1". One is bowed slightly on one end. Is there a way to flatten that end?
There are two possibilities:
Add a bracing bar to the bottom of the table that holds the board flat. The table is clamped strongly to bend out the bow, then the board is screwed into the brace. The supports for the table have to be strong and rigid for this to work.
Flatten the board itself. To do this, the board is removed from the table and soaked in a trough of water for 48 hours. Then the board is clamped to a rigid and flat surface while it dries. Ideally the board should be allowed to dry in a room that has a dehumidifier so that the air in the room is very dry. When the board is perfectly dry, it is removed from the clamps and shellacked so that it cannot absorb water (which would cause it to bow again).