bolbol
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Plating cadmium or chromium onto iron?
So I have a knife blade that my friend made by welding grooves on an iron piece. It doesn't seem to be pure iron because it's rusting very slowly and
it's not really soft. But regardless it's starting to rust, especially the parts that have been cross hatched by wire drill bits.
I was wondering if I could plate some sort of metal on it to make it rust resistant if I got the rust off.
I only have a pure piece of cadmium rod I can use, but I can also buy some chrome and plate that on it instead if it's a less costly process.
Any tips or suggestions?
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Artemus Gordon
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I can't help you with plating, but if all you want is to stop it rusting, use sand paper or steel wool to remove the rust that already exists, then
coat it liberally with WD40. Wipe off the excess WD40 and your knife should stay rust-free for many months. The WD40 will slowly evaporate away, so if
you think it will be stored for a long time without use, apply some paste car wax and buff off the excess.
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cyanureeves
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nickel sulfate plates easily onto steel but chrome is not that easy and besides you have to bright nickel plate first.sodium sulfate works great on
rust but you have to plate steel right away or it rusts even worse.i have used chrome on brass and steel and got a yellow lattice pattern
coating.plante 1999 said it was probably because of uneven surface and i recall him telling me before i even did it.ESP!
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bolbol
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To the first replier:
That definitely sounds like a good alternative. Will the smell of the WD40 stay with it at all times?
And to the second replier. So nickel and nickel sulfate as a catalyst or nickel plated directly from the nickel sulfate?
What about cadmium? Any guesses!
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MrHomeScientist
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Camphor also helps prevent rust, or so I've heard. They sell cubes of it that you put in your toolbox and it sublimates over to your tools to protect
them.
Chrome plating is a complex process, involving meticulous cleaning and (almost always) a base plate of nickel. The conditions required vary greatly
depending on your application. It also likely involves hexavalent chromium, so take great care because it's a carcinogen. Search the web and ye shall
find plenty of sites that are devoted solely to this subject. Finishing.com is the first that comes to mind.
Cadmium plating sounds like a bad idea, due to the metal's toxicity (unless you want a self-poisoning blade I guess).
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WGTR
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If your knife is important to you, then baking out the parts immediately after plating is necessary, to prevent hydrogen embrittlement. This process
is especially needed for high strength steels. Otherwise, pieces of the blade can chip out, or the blade can shatter like glass in extreme cases.
The normal cadmium plating baths are made from cadmium cyanide. Bath make-up is one part of the challenge. After that, you have to consider how the
solutions will be safely used, stored, and how you will dispose of them when you're finished. Hydrogen sulfide will precipitate cadmium from cyanide
solutions, but this process is attended with special risks of its own.
Light chromated Cadmium has a pretty, multi-colored, yellowish appearance that appeals to a lot of people, and cadmium corrosion products are compact
(unlike zinc's). If you want to do something relatively safe, however, instead of cadmium I'd suggest a zinc coating. Zinc can be easily
electroplated from sodium zincate, and the product can be buffed out to a shine.
Keep in mind that I know nothing about knife-making...
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cyanureeves
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nickel sulfate goes onto steel but leaves a brush nickel plate surface.there are others who add a bit of nickel chloride,tartaric acid and other stuff
for a bright nickel.i have a bunch of tools that i zinc plated using zinc and sulfuric acid and they are still holding pretty good. they are grey
looking but honestly i have not used them since so i dont know how they will hold up against salty sweat.nickel sulfate will also plate brass,copper
and steel. i have plated pennies,copper tubing,brass belt buckles and steel bolts.getting rid of cyanide plating solution is hell and takes the fun
out of it for me.i was rinsing out a belt buckle last week in bleach to neutralize copper cyanide using no gloves.i walked back in the house for a
spell and my heart started racing like mad and i had a metallic taste and tingling on my lips.i said a prayer ,walked around breathing deeply and
recovered.half an hour later i had my left hand over my mouth and smell my fingers and there goes my freaking heart racing again.no more prayers this
time just staying away from that crap,maybe it was a panic attack. i know it is stupid to not use gloves but it's stupid to even use poisonous stuff
without gearing up.it takes a bunch of different buckets for this and that to plate anything. i will bring out my gas mask again.
[Edited on 11-19-2015 by cyanureeves]
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Dr.Bob
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Plating a knife would make it hard to sharpen, so that seems pointless. Better to just get some knife stock and grind a knife blade out of it then
make a nice handle. Plus, as stated, plating metals is really a pain. A friend asked to help plate an old car bumper and once I saw the work, I
told him to send it off to someone who knew what they were doing. It would be faster for me to fabricate a new one from stainless steel.
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bolbol
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Sharpening is not an issue. I wont mind a rugged blade tbh because its not really perfect in the first place.
Is there anything besides nickel/zinc/chromium that I can plate on the knife? I mean im sure there is but I'd need instructions on the elctrolytes
needed, the type of cell needed, and the amount of electricity that I should give it..
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zed
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Well, yeah. You could Blue it. As in gun bluing. Or, you could coat it with vegetable oil, and carbonize the oil. As in tempering a new cast iron
pan..
There after, the carbon deposited, can be oiled occasionally and thereby offer pretty good rust resistance.
Stove paint is an option. And, there are probably many other chemical treatments, that do not involve electroplating.
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