4 Answers

Find out here>>http://www.dummies.com/how-to/content/how-to-remove-water-stains-from-wood-furniture.html

I've used a little white vinegar and then repolish.  Works great on your car too for waterspots. Just be sure to put wax back on it.

my mom used to use something called Old English Oil . Don't know if they still make it, but try to find it, b/c it works.

To get rid of those telltale watermark rings left by sweating beverages, gently rub some non-gel toothpaste on the wood with a soft cloth. Then wipe it off with a damp cloth and let it dry before applying furniture polish. For even stronger cleaning power, mix equal parts white toothpaste and baking soda...Readers Digest

Yup ,that does work.  The rings are from the glasses or cans with a cold liquid like tea or beer. The containers condense water out of the air and runs down the sides of the container. The ph of the water that is condenced is 5.5, which is acetic and it dissolves the the surface of the can or glass while also bleaching the wood where the aluminum and/or glass is deposited as a white powder. Waxes and polishes help to protect wood from this damage but is generally easy to liquify in the mildly acidic water and makes getting those rings out a challenge. Armed with this awareness I choose to try a drop of nail polish remover (acetone) to completely remove the ring stain and then, when completely dry, use wax to re-polish the the area where the polish had been removed.