file restore

[RobWilson]

evening lads


A couple of quotes from Workshop Receipts for the Manufactures,Mechanics & Scientific Amateurs. Vol 1 1885


Renovating Files

The file to be first cleaned from all foreign matter, and then
dipped in a solution of 1 part Nitric acid,3 parts Sulphuric acid and 7 parts water ; The time of
immersion will be according to the extent the file has been worn and the fineness of
the teeth , varying from 5 seconds to 5 minutes .
On taking out of the mixture ,wash in water , then dip in milk of lime ,wash off
the lime ,dry by gentle heat, rub over equal parts of olive oil and turpentine , and
finally brush over with powdered coke.

Galvanic Method.

Well worn files are first carefully cleaned by means of hot water and soda;then placed in connection
with a positive pole of a battery, in a bath composed of 40 parts of Sulphuric acid, 80 parts of Nitric
acid , and 1000 parts water . The negative pole is formed of a Copper spiral surrounding the file , but not touching
them; the coil terminates in a wire which rises towards the surface . When the file has been ten minutes in the bath
they are taken out .washed and dried.

Interesting stuff

Rob