Re Generated files

When I was an apprentice, there were (besides shape, size and cut) files that were 'cut' or re-generated. I believe re-gens were blunt files which had been sharpened by acid dipping. The form was not quite so accurate as a cut file, but they were OK for rough stuff.

Anyone come across these, and could we re-cut blunt files in a home environment ?

BobH

Never heard of that before. At my apprentice training school the only use we made of worn out files was to convert them into scrapers.

Later on though when I worked in a tool room there was a chippies shop next door and there was always a demand from them to make special purpose cutters from our old files.

Rik

I've used this technique when I didn't want to wait for new files to be delivered: **LINK** It works OK but the file doesn't stay sharp as long as a new one.

Russell

I've had reasonable success by doing it electrolytically.

I used dilute sulphuric acid from my local battery supplier as the electrolyte, from memory let down about 1:3, and a 1 v car battery charger as the power source, but just make sure you connect everything electrically before powering up as sparks and hydrogen are not ideal bedfellows in one's workshop. This is even more important when powering down.

The file needs to be the anode, and the cathode should face all sides of the file to be sharpened.

For the tank, I used a plastic measuring cylinder as it is tall and thin, thus minimising the amount of acid needed.

The cathode was made from a spiral of cunifer brake pipe as I had it lying around at the time.

For obvious reasons, goggles, gloves, old apron etc are to be advised, as it doing the job outside the workshop to save corroding anything.

Clean the file in caustic soda to degrease before you start, and rinse in a bucket of water following sharpening.

An immediate application of your favourite aerosol water displacer should follow as it will corrode frighteningly quickly. I used WD40.

Good luck and take care.

As I'm sure you've sussed, I meant a 12v Battery Charger.

A safer way than using Sulphuric Acid is to use ordinary household "Washing soda" solution of around 1 cup full of crystals to 1 gallon of water.

With the file-files connected to positive and the negative to a lump of lead steel or carbon block.

True the result is not a 'New" file but one that can be used for roughing out and then finish with a

new file.

Avoid stainless steel as an anode or cathode in this process and the contamination from chromium in the brew.

A DC welder can be used as an alternative to a battery charger you must NOT use at a HIGH amperage setting as the results can spectacular and very DANGEROUS. Lowest setting only is sufficient.

Eric

G'day. Many years I read the advice to chuck the files into the garden for a few weeks and let nature sharpen them.

I was recently researching as to how 'Chemically Sharpened' fishhooks were made so deadly (it works btw, don't drop one on your toe) with the idea of using an electro-chemical sharpening process on lathe tool edges, scribers etc. Although I have not yet attempted it, the process looks viable. A goggle search on electro-chemical sharpening can turn up quite interesting results.

Regards * Danny M *

Edited By Danny M2Z on 07/04/2014 10:00:04

There is a company still in business I think in the UK that processes a file 2 or 3 times for commercial users. It has been mentioned on a thread before on here or HSM. No idea who it was though and google is overwhelmed by computer file responses.

I read a description of one process that used an initial treatment to create a plating or precipitate on the back of the teeth, so that only the cutting face was eroded by the second stage.

neil

Just a small point..

If you use lead electrodes with a washing soda electrolyte, you'll notice a white precipitate on the bottom of the tank. That's lead carbonate or White lead. Don't let your children eat it or put it where anything else can eat it. it's quite toxic.

I only discovered this after using lead anodes and washing soda electrolyte for electrolytic cleaning. Not a major issue, but be aware.

Thanks for that warning Mark. Ian S C