Kitchen sinks can easily become clogged during food preparation. While it might be necessary to call a licensed plumber if there is a serious blockage, in many cases kitchen drain blockages can usually be resolved without professional help.
The equipment required includes a classic-style plunger, petroleum jelly, and gloves and safety glasses.
Try to unclog the blockage with some boiling water first. If this does not work, fill up the sink so the water reaches the rubber area of the plunger. Apply a lining of petroleum jelly around the rubber ring of the plunger. This creates a seal and makes the plunger much more effective.
Cover eyes and hands with protective gear if a chemical cleaner has already been poured down the drain.
Unclogging the drain
Set the plunger over the drain, ensuring that only water and not air is in the cup of the plunger. The goal is to force out the clog by using the water.
Start thrusting the plunger up and down, ensuring that the seal is maintained during the process. Do this 20 times, and on the final plunge pull the plunger back away forcefully. Top up the water in the sink if required and repeat until the drain has cleared.
Note that prevention is always better, and drain clogs can be avoided by catching food debris with a suitable strainer fitted over the mouth of the drain. Oils and grease should never be poured down the drain, as they will solidify and cause debris to be stuck in the pipe.