Acid for random etching a blade

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Dec 30, 2007
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Hi, I would like any recommendations:

I am experimenting with a few old blades, a couple are stainless, and a couple are carbon.
I would like to deliberately scar the blades in a random pattern. Has anyone worked with this suggestion before? I am expecting the acid to penetrate by 0.5MM (+/-)

Thanks, Jajimi
 

knarfeng

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Welcome to Bladeforums.

This might better be asked in the Maintenance, Tinkering and embellishment forum.
http://www.bladeforums.com/forums/forumdisplay.php?f=794

I've never tried and have no interest, but if I were going to fuss with this I might try hydrochloric acid for the stainless, but it will eat your edge all to heck.

A number of acids will work on the carbon steel.
 

Larrin

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Ferric Chloride works fine on most martensitic stainless steels, as well as carbon steels, and it's a lot easier to work with than HCl.
 
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May I ask why you're interested in doing this?

The first answer which comes to mind isn't a very flattering one.
 
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As other posters have noted, both hydrochloric acid (HCl)and ferric chloride (FeCl3)will work. HCl is also known as
"muriatic acid" and is sold in swimming pool supply stores, Home Depot, etc to adjust the acidity of pool water.
FeCl3 is sold by electronics hobby suppliers as a 'PC Board' etch.

Be CAREFUL with both these, they are both corrosive and will burn skin, eat holes in clothes and have nasty fumes
that will eat your lungs and eyes and corrode metal items that are stored in the same room.

When used to etch steel/iron they provide "grain relief", that is, they will show the boundaries of the
metallic grain structures on the metal surface.

They will NOT make a plain blade appear to be Damascus. After acid etch and a few other magical treatments
they can give an 'antique' finish like the one seen here:
http://www.agrussell.com/knives/by_...wrangler_large_bowie_with_beaded_sheath_.html
BUT don't expect to fool experts with a synthetic antique finish; a close analysis of the blade surface patina
can easily differentiate between a real antique and a chemical look-alike.

Also, the acid WON't etch nor penetrate to .5mm unless you leave it to soak a LONG time. The problem is that you
should mask off the blade areas you don't want etched ( black vinyl electrical tape will probably work),
but most masks will fail by the time the etch reaches .5mm.

Bottom line is: you'll need to take strict safety precautions, experiment with masks, soak times, etc before you
risk a valuable blade.

Last word: do all this OUTSIDE...one whiff of HCl fumes and you'll know why...after the coughing fit has subsided.

JMH
 

Larrin

Knifemaker / Craftsman / Service Provider
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Ferric Chloride isn't nearly as bad as HCl, you don't have to worry much about fumes, corroding metals, or missing skin.
 
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Ferric Chloride isn't nearly as bad as HCl, you don't have to worry much about fumes, corroding metals, or missing skin.

True...but since FeCl3 is a precursor of rust (Fe2O3), it will stain clothes and skin badly.
But I think I'd use it in preference to HCl.

JMH
 
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just use the knife and let it become old by itself...it will look a lot better, and will not lie about its age
my tought , anyway
 
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I'd like to know what Montejano or Kiku use, their work etching steel is great.
 
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I'd like to know what Montejano or Kiku use, their work etching steel is great.
Found this from Montejano on another forum...scroll down in his post for the English translation:

http://www.britishblades.com/forums/showthread.php?p=85644

There's also info using other materials, but BE CAREFUL when using mixed acids,
they are VERY DANGEROUS. While small droplets of HCL will sting if you splash some on your arm,
mixed acids have the capability to 'dig in' immediately, especially if heated...don't heat your etchant !

AVOID HF (hydrofluoric acid), it's a weak acid but a VERY TOXIC POISON. It will migrate thru the skin and
attack BONE, and it doesn't neutralize very quickly in flesh as most other acids do.
The fluoride ion will keep going thru flesh and depending on your level of contamination,
AMPUTATION is sometimes required to
SAVE your LIFE !
I saw a case where a guy spilled about a pint of HF on his chest and stomach...nothing the ER
could do except dose him with morphine..he died a few hours later.
It's not worth it to use HF.

See: http://en.wikipedia.org/wiki/Hydrofluoric_acid

JMH
 
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Thanks to all, especially FlashLife.
No I am not trying to imitate damascus, nor fool anyone. These are old blades anyway. Just doing this for myself as I rebuild for a hobby.

Regrads, Jajimi
 
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