Kitchen sinks come in many different colours (white, silver, black) and materials (stainless steel, acrylic, porcelain). The finishes on these sinks will last a lifetime if maintained correctly. However, many homeowners want simply a new sink colour, not a brand-new sink. Porcelain sinks should only be refinished professionally, but stainless steel and acrylic ones can be painted and repaired in much the same way. This can be achieved with proper painting preparation; without it, paint will chip and ruin the sink. Painting your kitchen sink isn't difficult, and, depending on its size, it can be done in two to four hours.
Remove all hardware from the sink. Disconnect the water lines from the bottom of the sink, remove the nuts that hold the sink into place and slide the water faucet out of the sink. Remove the drains from the bottom of the sink by loosening the nut under the cabinets and removing the drain up through the sink pan.
Clean the sink with acetone and a cotton rag. Make sure that you remove any excess dirt and grime from the sink pan. If necessary, use a scrub pad to remove any stuck-on material.
Sand the sink with 120-grit sandpaper. The purpose of this is to scratch the surface enough to give the paint something to stick to. You don't want to remove any sink coating with the sandpaper, just scratch the surface so that it isn't glossy. Wipe the sink down again with the acetone, making sure that no particles remain.
Tape the countertop around the sink with a painter's plastic drop cloth and tape. Use green tape to begin with---green tape will prevent paint bleed---and tape a 2-inch-wide area from the edge of the sink flange and over the countertop. Make sure that the tape doesn't overlap the sink flange. Once you've laid down a 2-inch-wide strip around the sink, cover all areas surrounding the sink with plastic---out to about 3 feet on either side surrounding the sink. You want to create an isolated area in which to work without getting paint on the countertop. If you have an undermount sink, carry the tape down over the exposed edges of the countertop edge that leads down into the sink.
Spray the sink with primer, and allow to dry. Stainless steel and acrylic sinks are very similar in the way they are painted. The exception is that acrylic will not be primed before painting. Primer will leave a fine film of dust once it dries; remove that dust before painting. Then apply the colour coat, holding the spray can 6 to 8 inches away from the surface. Make sure that the paint is oil-based enamel so it will adhere well. Make the first coat thin---there is no reason to try to put all the paint on at once. After the first thin coat has become tacky (about 15 minutes), apply a second thin coat. Follow drying instructions printed on the can, and then apply an extra coat. Allow to dry for 24 hours before use.
Reinstall the hardware. Be careful not to scratch the paint when reinserting the faucet into the sink holes. Attach the nuts that hold the faucet in place, and then reattach the water lines. When reinstalling the sink drains, you will need to apply a thin layer of plumber's putty beneath the flange of the sink drain, between the flange and the top of the sink drain hole before retightening---this will allow a waterproof seal. You can purchase plumber's putty from your local hardware store. Follow directions on the container for use.
Take your time when applying coats.
Always wear eye protection and dust masks.