Q. My kitchen cabinets are birch and the finish is stained, marred and irregularly worn. I don't want to refinish them, but wonder if you can tell me how to prepare them for painting, and what kind of paint to use? Mrs. R.S.S., New York City

A. The first thing I would suggest to scrub them thoroughly with strong detergent and water. After the wood is completely dry, sand with medium-grit paper until the surface is smooth and there is no gloss left anywhere. Then apply one coat of enamel underbody, followed by two coats of either high-gloss or semi-gloss enamel.

Q: My kitchen and dinette floors have linoleum tiles that are cemented down on tar paper (felt) floor covering underneath. I find that even a damp mop cleanup causes some of the tiles to lift up if I use a little too much water. I would like to install a new floor of vinyl-asbestos tile. Can I install this over the old tile by just cementing the new ones on top?-R.G.E., Red Hook, N.J.

A. I do not advise this . Linoleum tiles and the felt or tar paper were put down with ordinary linoleum cement years ago. This type of cement is water soluble, which is why the tiles lift up easily when water is left on the surface. Although new tiles can be put down over the old ones that are still bonding well, your old tiles obviously are not, and I advise taking all the old flooring material up first.

Q: I recently moved into a house with a blacktop driveway. This driveway has some slight depressions that accumulate water that may freeze during the winter. Can these be filled in, or must the whole driveway be broken up and resurfaced?-D.B., Spotswood, N.J.

A: Almost all hardware stores and lumberyards sell bags of special patching material for use on blacktop driveways. These can be used for filling in depressions, cracks and holes. If the depressions are very shallow, however, you may have to chop them out slightly to get a patch that will be thick enough to last (read the directions on the bag). You may find the patches are darker than the surrounding areas. If this bothers you, the entire driveway can be coated with blacktop sealer-which is a good idea every two or three years in any case.

Q: Is there any type of paint that can be used successfully on ceramic tile if I want to change its original color?-S.N., Philadelphia, Pa.

A: Actually, any good-quality enamel can be used over the tile and will stand up reasonably well if you make sure the tile and grout (joints) are thoroughly cleaned first, and if you use a undercoat as the primer. As a practical matter, however, the type of paint that will serve best is a two-part epoxy (you can buy it in most paint and hardware stores). This type bonds better than regular paint in most cases and gives a harder finish, but you have to take extra care with cleaning and preparations as described on the can.

Q: I was told that the best way to fill a crack in a plaster wall is to widen the crack first by cutting it out, then wetting the surface before applying the patching mixture to it. I followed these steps carefully, but when I finished, the crack promptly opened again. I used plaster of paris mixed with water for the patching. What am I doing Wrong?-A.A., Brooklyn, N.Y.

A: The answer lies in the material you used. Plaster of paris never should be used straight for patching. In fact, it should not be used at all for small patches. For cracks, the best material is a spackling compound. Either the ready-mixed or powdered type which you mix yourself (with water) can used. You still should cut the crack out, and the spackling compound dries more slowly and is less likely to crack or shrink.

Questions about home repair problems should be addressed to Bernard Gladstone in care of The New York Times Syndication Sales Corp., 200 Park Ave., New York, N.Y. 10017. Question of general interest will be answered in this column, but unpublished letters will not be answered individually. CAPTION: Illustration, No Caption, By Mary Myers for The Washington Post