Shifting Blockages from Clogged Sinks
Most traps are easily dismantled, but gaining access to them is often more difficult. For this reason, it’s always worth trying to clear the blockage by simpler means. Plunging works best where there is a single appliance connected to the trap. Where there are several, such as a two-bowl kitchen sink with drainer hoses, it is less effective. Poking with coat-hanger wire or a sink auger works well on ‘U’ bends, less so on bottle traps.
Burning with caustic soda is very effective on blockages caused by build-ups of grease — but the chemical itself is highly dangerous and must be used with care.
Caustic soda can damage old lead piping but won’t harm plastic. Any water trapped in the fitting must be removed first (see Problem Solver – Problems with Sink Traps).
2. Using the largest possible plunger, place it over the waste outlet and work it up and down vigorously to build up the force of the push-pull effect.
Making a sink plunger
"If you don’t have a sink plunger, try using an old plastic ball cut in half — or at a pinch, a large saucepan lid. Simply pump up and down over the waste outlet in a rapid succession of short, sharp strokes."
2. When you feel the auger move easily, withdraw it slowly turning the handle at the same time. With luck, thewill carry the obstruction with it.
CLEARING CLOGGED METAL SINK TRAPS
♦ Unscrew the clearing eye by gently tapping on one of the lugs with a hammer and bolster — or similar wide-bladed tool. If the eye is tight, arrange some means of support to avoid placing strain on the trap.
♦ Hook out the obstruction with a piece of bent coat-hanger wire.
♦ Wrap a few turns of PTFE tape around the thread of the eye before replacing it, and take care not to over-tighten.
Caustic soda and other proprietary drain clearing products are extremely harmful to the skin, so always follow the manufacturer’s instructions. Wear gloves and some form of eye protection when using caustic soda, and keep the tin out of the reach of children.
Also, never mix household cleaning products (for example, bleach and lavatory cleanser) in an attempt to clear a trap. Some combinations produce awhich is, quite literally, lethal.