Cleaning Fine Files

[VicParticipant @vic]

I’ve been gifted some small files. Most of them have cleaned up well but I’m having difficulty getting the very fine ones clean. I assumed it was aluminium stuck in the teeth but caustic soda failed to dissolve it. I’m assuming they’ve been used on stainless steel as the chips are bright silver. Any ideas, I’ve tried acid as well to no effect.

[DiogenesParticipant @diogenes]

Try a piece of flat brass brought to a single bevel to try and ‘push’ the spalls along the line of the file teeth and ‘out over the edge’

If you can get hold of a fine, stiff, and densely-populated file card they do work a treat even on Swiss files, but unfortunately they don’t seem to make ’em quite like they used to..

[JasonBModerator @jasonb]

Is it soft solder?

I use a piece of copper and push it across the fill following the diagonal of the teeth.

[MacolmParticipant @macolm]

Sometimes I have needed to use a pin or needle point across each “valley”. This is usually not as bad as expected, perhaps a couple of minutes per file since only one pass per groove is required.

 

[BazyleParticipant @bazyle]

I wonder if ultrasonic cleaning can work its magic getting under the dross. Or even electrolysis to make hydrogen bubbles under it?

[Nigel Graham 2Participant @nigelgraham2]

Anything chemical, including electrolysis, risks damaging the files themselves.

Ultrasonic cleaning won’t hurt the tool but is unlikely to dislodge filings compressed tightly into the gullets. It may remove contaminants that are holding others.

.

Diogenes’ and Jason’s methods are the best; though I generally use brass not copper.

You can also reduce “pinning” (jammed filings) by rubbing blackboard chalk into the teeth, once clean. Note: blackboard “chalk”, not the rock, which could be abrasive itself or may contain grains of sand or flint.

I was taught those two tips in Metalwork at school! Thinking about it, and not knowing what blackboard chalk is made from, I wonder if talcum powder would be as effective. If nothing else you’d have some sweet-smelling files…

[noel shelleyParticipant @noelshelley55608]

Hammer the end of a bit of 1/4″ copper tube flat for 1/2″ and push across the teeth, works a treat ! Noel.

[VicParticipant @vic]

Thanks for the tips folks. I’ve got some copper pipe and some brass rod so I’ll give it a try.

[DiogenesParticipant @diogenes]

“..I wonder if talc..”

Yes, I use ‘Engineers Chalk’ which are just bars of natural Talc, and it is more ‘slippery’ than ‘chalk’ chalk..

..I’m still not sure that it makes any marked difference, though..

[Mike HurleyParticipant @mikehurley60381]

I remember being taught the ‘chalk’ tip when dealing with gummy materials, always workd OK for me.

I do recall reading several articles in the past suggesting that ‘file cards’ did more harm than good generally. Not that I had ever really noticed any problems with occasional use. However, I have in recent years got in the habit of using brass (like noted in several replies here) which works fine.

Mike

 

[VicParticipant @vic]

I’ve got some sticks of French chalk I’ll be trying after I get the files clean.

I got these some years ago for marking hot metal.

https://waltersandwalters.co.uk/engineers-french-chalk/FLTS-Engineers-Welding-Welders-French-Chalk-Sticks

[JohnFParticipant @johnf59703]

By far the best way to remove pinning is the corner of a brass/copper/alloy bar — as suggested by Jason and others.

Although chalk can help to prevent pinning you can use cutting oil — yes I know its frowned upon but believe me is does work particularly well in steel.  Just brush a small amount on the teeth — I was told this many years ago by a colleague in Brum and his words were “its a cutting tool a’int it ”

John

[Phil PParticipant @philp]

JohnF

I agree, my dad showed me that trick 50 odd years ago.
I use the good old fashioned stinky soluable stuff neat, and it works a treat.

I also use it when tapping or gear hobbing steel as well.

Phil

[GeorgineerParticipant @georgineer]

An old chap I once worked with used what he called ‘monkey juice’ – he’d spit on the file before starting. It seemed to work well, but was possibly less hygienic than cutting oil.

George

[Russell EberhardtParticipant @russelleberhardt48058]

I’ve used talcum powder on files for years.  It is particularly effective at stopping aluminium clogging files.

As an aside the biggest talc mine in Europe is well worth a visit. It is on a massive scale, producing 400,000 tons of talc a year.  Guided tours are available in the warmer months.

https://www.mindat.org/loc-1745.html

Russell

[Nigel Graham 2Participant @nigelgraham2]

Thank you for that “aside” information. I’ve just come back here from reading it, and I’ll pass the link to our local geology club!

There are some tiny talc veins in The Lizard, as I recall… Though those may also contain asbestos, as the two minerals do sometimes appear in association.

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