Holding water in a sieve
Pour some oil over the wire mesh of a kitchen sieve and shake out the overload so that the holes are open. Cautiously pour water into the sieve from a pitcher, letting the water run down the side of the sieve. When the sieve is about half full, hold it over a sink or pail and observes the bottom. You will see the water pushing by the openings but the surface tension keeps it from running by. Touch the bottom of the sieve with your finger and the water should run by.