Old files

I think about half a year ago we had a thread about bringing old
files to a live again, I have tried to search it in the archives, but
till now with no success. Can anybody help me? It was something with
2 x sulphuric, 1 x nitric acid and 7 x water, or how was it?? Any
lead would be mostly appreciated.

Kind regards
Niels L?schal, Jyllinge, Denmark
@L_F8vschal
phone (+45) 46 78 89 94

Hi,

I’m not familiar with a specific recipe for restoring old files, but
when mine get dull I generally clean and degrease them and then dip
them into dilute HCl for a while, watching the bubbles; when I think
the acid has done its work long enough I take them out. That’s fairly
ad-hoc but it does work. I’d also be interested in hearing about
specific formulations of acid combinations.

The principle is the same whatever the acid: to dissolve away enough
metal that the turned-over dull edges of the individual file teeth
become sharp again. You can only do this so often, though.

Cheers,
Hans Durstling
Moncton, Canada

Could you please tell me what HCI is? Thanks.

Also, is naval jelly harmful to use on files? If so, is there another
way to get rust off files?

Leda

Here we go again,

a fast way to sharpen old files is like this:

Clean the file in a hot washing soda bath with a brush, or with in
other way of decreasing. Than put them in the following mixtuRe: 7 parts
water 3 parts sulphuric acid 1 part Nitric acid. In a few minutes ready.
(remember first water that acid and be aware of your own safety)
neutralise in washing soda again.

This recipe comes from a nice book from 1967 called “mengen en roeren”
(mixing and stirring), 2000 populaire chemische recepten, by Drs L.P.
Edel. It is not available anymore. The latest versions after 1970 are
censured and very brave. The old ones are great.

Also, is naval jelly harmful to use on files? If so, is there another
way to get rust off files?

As long as you neutralize it and rinse and dry the tool, if anything,
it will sharpen the file a bit.

Ron Charlotte -- Gainesville, FL
afn03234@afn.org OR @Ron_Charlotte1

noneI use the exactly the same recipe as Martin Niemeijer. My
version is from ‘Workshop Receipts’ by E.Spon, published in 1890.
After de-greasing the file, dip for anything from 5 seconds to a
minute, depending on how fine the file is. I use an old 100ml
graduated cylinder. Wash and dry the file, then rub with chalk. Long
live Orchid Digest. David Kelsall (UK)

noneMy version is from ‘Workshop Receipts’ by E.Spon, published in
1890. It uses exactly the same proportions of acids as that used
Martin Niemeijer. After de-greasing the file, dip for anything from 5
seconds to a minute, depending on how fine the file is. I use an old
100ml graduated cylinder. Wash and dry the file, then rub with chalk.
Long live Orchid Digest.
David Kelsall (UK)