Q: I read your article about using tung oil on outdoor furniture, and put a first coat on my redwood patio table. I followed your and the manufacturer’s instructions, and the table looked great when I finished. I did the work at midday, and it was dry to the touch by dark.
There was heavy dew the next morning, and the table is now covered with small gray spots that remained even after it dried thoroughly.
Now I don’t know what to do and have covered the table in the meantime. Do you have any suggestions on how to remove the spots?
A: Unfortunately, even though the finish was dry to the touch it was not "dried thoroughly." But don’t fret. It’s fixable.
Oil finishes need to be not only dry to the touch, but also thoroughly cured. That means all the moisture must evaporate. Think of it this way: You’re painting with an acrylic paint, and you mistakenly leave the can open overnight. When you return the next day, a thick film covers the surface of the paint. But puncture the film, and out oozes liquid paint. If the can is left open for months, all the water evaporates and only a solid mass of acrylic remains. At that point, the paint is fully cured.
The tung oil is moist below the surface. Oil and water don’t mix, and when the morning dew arrived, so did the gray spots.
Repairing the damaged finish is easy. Uncover the table and move it into the garage or some other place where the morning dew won’t affect it. Here’s an old boat trick to fix too much sealer (tung oil or urethane) applied to teak decks: Rub out the spots with 90 percent rubbing alcohol using "0000" bronze wool. This will remove the discolored finish and won’t harm the wood. Rubbing alcohol is cheap and not as toxic as acetone.
Recoat with a thin coat of the tung oil. Several thin coats are much better than fewer thicker coats. Give it a day to dry. When dry to the touch, lightly rub the surface with the bronze wool and recoat. Repeat the process until you’ve got four or five coats of oil on the wood. Then let it sit for a week, away from any moisture to cure.
Now onto a different issue:
Two months ago, we responded to a reader who complained of mineral deposits in her toilet bowl. We suggested products such as CLR or Lime-A-Way to dissolve the deposits.
One reader swears by a product called a Pumie Scouring Stick. She says, "I picked one up years ago in a hardware store and it works great removing hard water deposits and such. It is easy to use, easy on the hands, and leaves a fine dust, which easily flushes away."
Another reader suggested that sanding screens designed for plaster or drywall also make short work of hard-water deposits.
Both alternatives are chemical-free and won’t mar the porcelain.