Q: One of our windowsills is...

Q: One of our windowsills is rotting. We know that it was caused by wetness. Do we have to replace the sill, or can it be saved? A: Perhaps you can prevent the rot from spreading by filling holes in the sill with epoxy resin sold by boating dealers. Use a portable electric drill to make 3/8-inch or -inch holes in the sill, every few inches apart. Fill the holes with the resin. Once the rot has been arrested, paint or finish the sill.

Q: We are purchasing wall-to-wall carpeting and have to do some measuring to determine how much we need. It is sold by the square yard, but we aren’t quite sure how to determine how many square yards there are in the room. What is the formula? A: Measure the room carefully, leaning a little bit to the generous rather than the skimpy side. Multiply the length of the room by its width in feet. When you get the result, divide it by nine and you will have the square yardage of the room.

Q: I have never used shellac but have been told that it is easy to use. I have a project for which I would like to try it. Any tips? A: Don’t use shellac in high humidity. Don’t use shellac that is more than 6 or perhaps 8 months old. Also, shellac can rarely be used as is; it must almost always be thinned with denatured alcohol. The first time you use it, make a mixture of half shellac and half denatured alcohol. Later on, you will learn what mixtures are best for what purposes. It is much better to apply three or four thin coats than a single thick one. Shellac can be applied with a brush that is used for shellac only, or it can be put on with a clean, lint-free cloth. Shellac produces a fairly clear finish, but if you want a slightly orange shade, use orange shellac. The clear-finish type is called white shellac, but it really isn’t white.