If it is found that the obstruction is in the pipe beyond the trap, and that the trap can be opened or removed, pour the mixture directly into the pipe through a funnel, or if the mouth of the pipe is inaccessible by that means, force a piece of rubber tubing or hose into the pipe and attach the funnel to the upper end.
To keep the drains in good working order it is well to flush them occasionally with a smaller quantity of this mixture. If it is difficult to obtain, caustic potash there are numerous prepared drain-pipe solvents on the market at a reasonable price, the best of which probably depend mainly on caustic potash for their grease-cutting qualities.
In flushing out drains, avoid the use of what is popularly known as "lye" or any other preparation in which caustic soda (sodium hydroxide) predominates. Upon coming in contact with grease such chemicals form a hard soap, which is dissolved with difficulty in hot water and is practically insoluble in cold water.
The same chemicals and methods of application prescribed for cleaning out traps, waste lines, and drains may also be used to melt obstructions of ice in frozen drainpipes.
It must be remembered that such chemicals should be used only in cleaning waste lines and traps and should never be placed in water-supply pipes.
If All of the Preceding Methods Fail.
In case the obstruction can not be located and removed by any of the methods described above, it is best to call a plumber, as complicated pipe cutting and fitting may be involved.
11. HOW TO OPEN FLOOR DRAINS
Floor drains are found in bathroom, cellar, and garage floors where water, dirt, and oil accumulate and frequent flushing or washing of the floor is necessary. The ordinary type of drain consists of a metal boxlike cup attached to the end of the drain pipe and covered with a strainer or grating. Just below the cup there often is a trap or bend in the pipe to catch particles which may pass through the strainer and also to form a water seal against odors rising from the pipe. Where there is no separate trap the box itself is constructed so as to perform these functions.
Causes of Clogging.
Floor sweepings and particles washed into the drain may lodge in the trap and, together with grease and oil, gradually fill it up and block the flow of water. Sometimes the holes in the strainer become clogged and prevent water from flowing into the drain.