2 Answers

Ashes

Use cigar and or cigarette ashes to remove those white rings left on your wooden furniture by wet glasses or hot cups. Mix the ashes with a few drops of water to make a paste, and rub lightly over the mark to remove it. Then shine it with your favorite furniture polish.

Baking Soda

Get those white marks — caused by hot cups or sweating glasses — off your coffee table or other wooden furniture by making a paste of 1 tablespoon baking soda and 1 teaspoon water. Gently rub the spot in a circular motion until it disappears. Remember not to use too much water.

Car Wax

Someone forgot to use a coaster and now there’s an ugly white ring on the dining room table. When regular furniture polish doesn’t work, try using a dab of car wax. Trace the ring with your finger to apply the wax. Let it dry and buff with a soft cloth.

Petroleum Jelly

Your most recent party left lots of watermark rings on your wood furniture. To make them disappear, apply petroleum jelly and let it sit overnight. In the morning, wipe the watermark away with the jelly.

Salt

Make watermarks left from glasses or bottles disappear by mixing 1 teaspoon salt with a few drops of water to form a paste. Gently rub the paste onto the ring with a soft cloth or sponge and work it over the spot until it’s gone. Restore the luster of your wood with furniture polish.

Toothpaste

You leave coasters around. But some people just won’t use them. 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.

Vinegar

To remove white rings left by wet glasses on wood furniture, mix equal parts vinegar and olive oil and apply it with a soft cloth while moving with the wood grain. Use another clean, soft cloth to shine it up. To get white water rings off leather furniture, dab them with a sponge soaked in full-strength white vinegar.

Read more: http://www.rd.com/home/7-ways-to-remove-water-rings/#ixzz2kRIgGuna

I have used a paper towel, with an iron set at lowest dry setting, no steam.  Hold it on for about 30 sec.  repeat as necessary.  If is sets smoke alarm off, you either held it too long, or the temp. is too high!