Q: I have deck chairs with vinyl straps. They have been out on an open deck all year and the straps have turned dark brown. However, the undersides have retained their original color. Can I do anything to bring them back to their original color, and if not, is there any kind of paint I can use over them?
A: Try scrubbing the vinyl with a strong solution of bleach. Mix one part fresh laundry bleach with one or two parts water and add to this a handful of powedered detergent. Scrub off with a stiff brush, allow to soak for a few minutes, then rinse off with plenty of water. If this doesn't work you can paint with vinyl spray coating, sold in many paint, auto supply and marine supply stores.
Q: Our entrance hall has a Vermont slate floor. Can you tell me the best way to clean it, and whether we should use a sealer on it?
A: Scrub it clean with a strong detergent solution. If the detergent doesn't get the stains out, use a dilute muriatic acid solution (sold in paint and hardware stores). Mix one part acid with three parts water in a plastic or glass container, scrub on and allow to set for 10 to 15 minutes. Rinse off with plenty of water. Wear rubber gloves and keep the acid off painted and metal surfaces. When thoroughly dry, apply two coats of clear penetrating sealer, made for use on stone, and renew this when it shows signs of wearing off.
Q: The house we recently moved into has lovely built-in walnut bookcases. The shelves, mostly on the under side, but also in the corners and along the sides, are sticky to the touch and books along the ends of each shelf are difficult to pry loose. Can you tell me what is happening and what I can do to keep the books from sticking?
A: Since you apparently do not know what the previous owner used on the shelves, I can only guess that he applied many coats of raw linseed oil or similar oil that never dries completely, or he applied so many coats of some type of oil, wax or polish that the result is sticky film that cannot harden. The first thing I would try is to sponge the sticky surface with a detergent solution, then wipe with a damp rag. If this does not remove the sticky film, try wiping with a rag moistened with paint thinner, following almost immediately with a dry rag you turn frequently. This should do it. If it doesn't then complete striping of the finish may be required.
Questions about home repair problems should be addressed to Home Improvement Department, The New York Times, 229 W. 43d St., New York, N.Y. 10036. Questions of general interest will be answered, but unpublished letters will not be answered individually.