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Re: torque conv./ inner tubes
Kevin Nardelle (knardell-at-accesscom-dot-net) posted:
> I have a bottle of CuS04 crystals but when I tried to plate something made
> out of nickel, the Cu formed very very thin and took a very long time to do
> so. I used 5,12,24 VDC 1.0A and the effect did not change much.
Kevin, the problem here is that, once you have enough voltage
to pass a given current through the plating solution, the voltage
*doesn't matter*! It's all in the current and time. One Amp is
also pretty low, if you want thick plating. I don't recall the
exact values of Avogadro's and Coulomb's constants right now,
but to within a few percent, it takes 10^5 (100,000) Amp-Seconds
of current to transfer one Mole of mono-valent ions. Since you
are dealing with reducing Cu++, it would take 200,000 Amp-Seconds
to plate out 63 grams of copper. This would cover roughly
7100 square millimeters of surface, 1 millimeter thick.
A toroid one meter in diameter, with a 20 cm cross-section (not
all that big, by standards of THIS group, at 40"x8"!) has a
surface area of almost 1.8 million square millimeters, or
something like 250 TIMES the above 63 gram surface, if
one millimeter thick. This would take 1.6 YEARS at one Ampere.
> I don't know what the amounts were that I mixed, water/CuSO4. Do you
> think if the solution was strong enough you would get even 1/8" out of
> it?
The above (40"x8") toroid, one millimeter thick, would consume
39 kilograms of copper. Ideally, your copper should come from
the electrode you are plating from, not the electrolyte solution.
You should only need sufficient CuSO4 to carry the ionic
current from copper cathode (+ supply) to workpiece (- supply).
> I very much like the idea and would like to hear how it comes out. I
> might try to plate a rubber ball the same way just for fun and see if I
> can get it thick enough. I'll let you know my findings.
I think that's the way to start!
Dave