Furniture, Wood and Cabinetry Finishing - black water stain on table

How is the best way to remove the black mark and then refinish the table top? I don't like tablecloths....

Black water stains indicate moisture has penetrated the finish to discolor the wood.

The stop must be stripped. Apply oxalic acid (wood bleach) as suggested on the container. Oxalic acid comes as a powder, usually in one pound containers. It is mixed with hot water to a saturated solution and then brushed over the entire top for uniformity.

Allow to stand several minutes, the wipe off. An additional application may be needed. Maximum results will obe tained with three applications. More is a waste of time.

Wipe the surface clean with water and rags. Allow to dry at least overnight.

Stain and finish to your specs. I would suggest a polyurethane - it's more durable.

Will the bleach penetrate the current finish, or do I need to use a stripper first to remove any poly that may be on the table initially?