RESTORING OLD FILES

Rotorua Morning Post, Volume 3, Issue 664, 17 October 1933, Page 7

RESTORING OLD FILES

Many motorists who do their own minor repair jobs have accumulated a j large nurnber of old files which have j been discarded because their teeth I ■have become h'opelessly clogged with metal. The usefulness of these files can be restored very quickly and cheaply. They should be left for a period of from 5 to 10 minutes completely submerged in a glass or porcelain vessel containing one-part of nitric acid dissolved in six pai'ts of water. They should be removed from the bath, and the eutting faees should be rubbed ■briskly over a board smoothly bound

with several layers of cloth. The object of this operation is to j remove acidfrom the eutting ends of ! the file teeth, while leaving a film of , acid over the clogging material bei tween the teeth. The files should then be left for about half an hour. j In that time the clogging material i will either be completely dissolved or ! so loosened that it can be dissolved ! with a hard brush. The files should i then be thoroughly washed, first in | water, to which a little carbonate of ! soda has been added, and then in | clean water. They" should then be j oiled until th'ey are required. I The nitric acid is an extremely eorI rosive solution, and the utmost care i should he exercised to ensure that it j does not come in contact with the hands or clothing.