Coppering process, galvanic technique

ArielSalaverria

ArielSalaverria

Joined
Mar 26, 2004
Messages
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I don't know how much time it's gonna be until I have time to make the new tutorials so here's the explanation for the galvanic coppering process (for carbon steels).

This is the method I'm using nowadays as it's way more resistent that the others I've been using before.

I put a liter of destiled water on a plastic or glass recipient and then I add 30g of copper cyanide, 25g of potasium cyanide, 15g of sodium carbonate and 2g of sodium hyposulphite.

I use a car battery (12V) with a charger, a variable resistance and a voltimeter (tension=2,5-3V)
The piece to copper gets connected to the negative and the positive goes to a copper barstock/flat barstock inserted on teh solution.

As reference, for a 6" blade I leave it 20 minutes at room temperature.


tutorialcoppered4_big.jpg


tutorialcoppered5_big.jpg



Regards,

Ariel
 
Thanks for sharing Ariel:
I can see a lot of potential for the thoughts you just shared, and want to say thanks for the information. How bad are the fumes from this process?
 
If you get any type of acid on the cyanide salts you will get HYDROGEN CYANIDE, very toxic , as in gas chamber. Store and handle them very carefully,do it outside or where you have an exhaust fan.
 
Ed, I'm honored that you find this interesting.

As mete said, it's very convenient to do this on a very ventilated place, using gloves, as this are toxic products. On the small scale that I use, I don't realy get much fumes.

Regards,

Ariel
 
Ariel: An highly skilled bladesmith once told me about a self tempering steel that had some copper in the chemistry. He stated that you could harden it and in 18 hours it would temper on its own due to the copper in the alloy. I have never played with it (that I know of) but his thoughts have always stuck in my mind. I wish that I would have known more questions to ask him at the time, but I was pretty green and simply accepted his statement. As I remember he said it did not make a great knife the way he worked it, but he wished he had experimented with it more as he felt it had promice.

It is something to think about! On the surface one would doubt there would be much influence on the whole blade, still another variable to play with - maybe?
 
Ed, that is really interesting, thank you for the info, I'll try to see if I can find more about that :)

Regards,

Ariel
 
You are probably thinking about 17-4 PH stainless steel. It's strength is from a different type of martensite plus precipitation hardening. Often the parts are made in the martensitic condition then given the precipitation hardening treatment. It contains 4% copper.
 
mete said:
You are probably thinking about 17-4 PH stainless steel. It's strength is from a different type of martensite plus precipitation hardening. Often the parts are made in the martensitic condition then given the precipitation hardening treatment. It contains 4% copper.
Click to expand...

Robert.. I'm sure glad you're on our side :D
you don't happen to know the
rock-well it's capable of do you? :confused:
and do you know the process of the precipitation hardening treatment...
 
This places claims 45RC

http://www.specialtyblades.com/materials/301_stainless.html

More info here:

http://www.hightempmetals.com/techdata/hitemp17-4PHdata.php
http://www.suppliersonline.com/research/property/metals/1752.asp

Small comparison of 17-4 to 300 series stainless

http://www.sensortronics.com/technical/stainless.htm

And of course lots of other links out there if you search. VERY interesting steel, looks like. 45 is rather soft for my liking for most knives, but a steel that(According to last link), is only 5% less corrosion resistant than 300 series stainless, while being hardeneable to 45RC and containing little to know carbon (0-0.07), is definitely interesting, even if it ends up not being useful for knives.
 
maybe a bad butter knife? :D
with less NICKEL (Ni) in it maybe you'd get less galling in working it then the 301 SS for use in guards or bolsters maybe?
it's interesting you'd get a higher RW with 301ss but not by much.
but I'd say it would have to be priced right to take it's place.
or just as well use the higher 400 series SS.
the so called self tempering may be causing a low RW maybe??
Mete can you comment on it..?
 
Dan ,301 'less galling' ? I've never machined 301 but are you confusing it with 304 ? 301 work hardens VERY quickly we used to make springs from it by cold rolling and drilling ,if you don't have the proper speed, feed and very sharp drill ,will work harden and become very hard !...I have a mobile radio antenna of 17-4 and it gets whacked by trees a lot so it's good for that !..I thought you all used 416 for bolsters ? what's wrong with that ?
 
mete said:
Dan ,301 'less galling' ? I've never machined 301 but are you confusing it with 304 ? 301 work hardens VERY quickly we used to make springs from it by cold rolling and drilling ,if you don't have the proper speed, feed and very sharp drill ,will work harden and become very hard !...I have a mobile radio antenna of 17-4 and it gets whacked by trees a lot so it's good for that !..I thought you all used 416 for bolsters ? what's wrong with that ?
Click to expand...
Robert I'm
just speculating,, with less NICKEL in it, maybe you'd get less galling in working it then the 301 SS
galling as in driving tight pins,,, I have few problems machining.
I guess I was thinking 300 series in general..
but I'm using some 303 not 304 if there's much difference?
 
While all the same series each of them has distinct differences. Are you using 303 or the free machining grade 303Se ? 305 work hardens the least , 301 work hardens by far the most .316 is the more corrosion resistant version of 304 with it's added Mo. Take your pick.
 
well I'd say free machining grade 303Se
only because it works fairly well, but I don't know for sure :(
it's from TKS..
 
Precipitation Hardening--- Precipitation hardening or age hardening was discovered by Alfred Wilm in Germany in 1906. He attempted to harden an alloy of essentially aluminum-2 atom per cent copper in an analogous way to steels by quenching treatment. the specimen was initially soft, but the hardness increased by a quenching treatment. The specimen was initially soft, but the hardness increased with time at room temperature after the quench. The results were published in 1911 without explanation. Merica, Waltenberg and Scott first attributed the hardening to a precipitation effect. This was an extremely imporant paper, for it pointed the way to development of a whole host of precipitation-hardened alloys.
 
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