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-----Acid copper plating on steel?
Quickstart:
It is usually not practical to do acid copper plating (copper sulfate) directly onto diecast zinc or steel parts because it will spontaneously 'immersion deposit' ⇦ huh? due to electromotive potentials, and the adhesion will be very poor.
Instead, it is conventional to use cyanide-based solutions, which often/usually contain Rochelle salts
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and are therefore sometimes called Rochelle copper.
For bright and/or heavy deposits of copper plating onto zinc or steel, the most common approach is to start with a thin layer of Rochelle copper plating, and follow it with a thick layer of bright acid copper. But an initial layer of nickel or pyrophosphate copper can alternately be applied.
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Q. I am having a problem with the theory of "acid copper" plating. Supposedly copper in this technique cannot be plated onto steel, which I want to plate it onto, then the book I am getting this info from says that cyanide copper bath is needed. Well, cyanide gave me asthma; so by doctors orders I can't work with it.
I am thinking maybe I should just give it a nice strong watts nickel plate then build up the copper and sand it to the desired appearance, then continue with the bright nickel, etc ...
Any info on this subject will help immensely.
Yours Truly
Barrett Russell
Saskatoon, Saskatchewan, Canada
1999
A. Hi Barrett. Yes, acid copper will 'immersion deposit' on steel, but nickel plating first should work. But do you think you should be plating at all if you've already had an asthma attack from it?
Ted Mooney, P.E.
Striving to live Aloha
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A. What you need is a copper strike. Several years ago cyanide was all that was available. Now, you can buy a pyrophosphate based copper strike which works fairly well.
You can use a nickel strike on steel. This is not a "Watts" nickel, and certainly not a strong one. There are sulphate nickel strikes available, but a "Wood's Strike" ⇦ huh? is the preference of many if not most platers.
Either nickel strike is based on low metal content and strong acid so that you do not get an immersion plate, which normally has very poor adhesion.
- Navarre, Florida
Sorry to not explain, I used to have asthma, and it went away; but plating and on top of that painting cars, kinda brought it back. It isn't severe tho', it taught a good lesson not to take anything lightly, I think it helped a lot in that aspect, and wasn't all for the worse.
Thanks for your concern though -- breathing better,
Barrett Russell
Saskatoon, Saskatchewan, Canada
A. You've got good advice: copper strike with low-grade pyrophosphate solution.
Anton CheglovA. If you're putting on heavy copper plate that must have a very strong adhesion to base material (like roll threads as a example) the best procedure other than cyanide copper flash was a very acidic watts nickel (not nickel strike) pH 1, and then a live entry system when going into the acid copper bath.
Chris Snyderplater - Charlotte, North Carolina
A. At a pH of 1, it sounds like a strike to me. Normally a true strike would have a lower nickel content to go with it, but that is not mandatory. It will just plate slightly faster, but still extremely slow.
James Watts- Navarre, Florida
Q. Could you please explain what the word 'STRIKE' means if we talk about electroplating.
Thanks in advance.
- Poznan, Poland
1999
aIn this context, 'strike' means a thin initial underlayer of plating in a preparatory plating solution often chosen to have a low tendency to immersion plate due to a very low concentration of metal in it
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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How to do heavy copper plating inexpensively
Q. Sir,
We already have a rochelle copper plating unit. I want to know is there any copper plating unit which is cheapest running cost and offers heavy deposit.
Ajay Aggarwalsteel - Panchkula, Haryana, India
by N. Kanani
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A. Hello Ajay. The usual, and probably best approach for reliable heavy copper plating is to start with Rochelle copper plating as you are doing, and then do bright acid copper plating on top of it.
My personal experience in the plating industry is that the cheapest way to do something is to do it right because the shop with the least rejects, defects, and work stoppages is almost always the shop with the lowest operating cost 🙂
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
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