Q. I have trouble keeping paint on a recessed radiator.The paint was applied before the heat came up, yet it is now cracking off. Is there a special paint I should use? S.C.T., Millburn, N.J.

A. Normally, recessed radiators are not painted-only the cabinet that covers them on front is painted. If yours are the exposed castiron type that has no cabinet or cover, you can paint them with any regular alkyd or oil base flat paint. If bare metal is exposed, use a metal primer first. All this must be done while the radiator is cool.

Q. The valves on my hot water radiators are "frozen" stiff and will not move. Is there any way I can loosen them so that I can once again turn them on and off asily? G.B., Waukegan, Ill.

A. Nine times out of 10 you can do this with penetrating oil-a special thin oil sold for the purpose of freeing rusted joints (its available in all hardware stores). Squirt the oil liberally in and around the valve stems, then tap lightly and repeatedly with a block of wood or a hammer handle to set up vibrations. Try again after about five minutes, and repeat two or three times if necessary. I may help to use a large pliers or pipe wrench on the handle when you try to turn it the first time, but be careful not to apply too much pressure-you might break the handle off.

Q. My old wicker furniture is unraveling around the feet. The strands are dry and encrusted with paint. I tried to bind them with fine wire, without much success. Would it be feasible to glue the loose strands in place?-W.M.N., Alexandria, Va.

A. I would definitely advise using glue, but I would combine this with binding with wire, or with staples driven through the peeling strands to hold them in place while the glue sets. (Binding with rustproof wire will accomplish the same purpose.) I would leave the staples or wire in place as added reinforcement in case the glue loosens in some spots. If the strands are very stiff and brittle, it sometimes helps to soak them by wetting with water before applying the glue and wrapping them back into place.

Q. Where our two chimneys go through the attic, parts of the bricks are crumbling. A sort of white mold seems to be causing this mold and then covering the bricks witth mortar to preserve them. Will this work?-J.A.W., Frederick, Md.

A. I am not sure what you mean by mold, but if it is a white powdery substance, chances are it is a condition known as efflorescence. This is a salt deposit created when dampness reacts with the excess alkalis in the brick and mortar. I would check the outside of the chimney to see if the mortar joints need repointing, or if the caulking between the chimney and the house wall needs replacing. Also, have the cap at the top of the chimneys checked to see if there are cracks that may be letting water enter the brickwork. After you have stopped all possible sources of moisture entry, and eliminated dampness in the brickwork, wash the white powder off with a dilute solution of muriatic acid. It may help to coat the bricks on the outside with clear water-proof sealer.

Q. I want to remove white enamel paint from rough bricks. Can you tell me how to do this? Mrs. J.W., Philadelphia.

A. The job can best be done with a semi-paste or heavy-bodied paint remover. I recommend a water-wash type. Spread on as thick a layer as possible; give it time to soften the paint-usually 20 to 30 minutes. Then scrub off with a stiff bristle brush that has been dipped into a detergent solution and water. Flush the residue away with plain water. Flush the residue away with plain water. Because brick is very porous, even this may not get every drop of white out. Sometimes the paint is so deep in the pores that it is almost impossible to remove all traces of it.

Q. My front porch has a tin roof that I used to paint every year with red lead paint. This paint is not available around here anymore. Do you know what I can apply to proetect the metal?-V.F.D., Cheltenham, Pa.

A. Red lead is a metal primer that helps protect against rust. Even when you used it, you should have applied a finish coat of outdoor paint over it. If you cannot get this type of metal primer, use one of the types containing zinc chromate. Scrape off peeling paint and wash off dirt, then apply a coat of the primer and at least one coat of exterior finish on top (trim paint or house paint. CAPTION: Illustration, no caption, By Mary Myers for The Washington Post