[SEL] Cleaning rusty engine parts with electrolysis

[Rob Skinner]

On Jan 11, 2007, at 5:47 PM, Ed stoller wrote:

> I thought Rick had a great simple way for me to remember which lead  
> goes where now I am all messed up.


Hi Ed,
Don't feel bad.  I have to stop and think about it every time I play  
with elecrolysis -- whether for removing rust or making rust.

If you can remember back to chemistry class, the iron oxide molecule  
is locked together because the iron ion has a positive charge and the  
oxide ion has a negative charge.  Opposites attract, and it's really  
hard to separate the two.

When doing electrolysis, remember that opposites attract, and like  
charges repel.  If you connect your part to the negative side of your  
power supply, and your anode to the positive, the oxide ions are  
going to be blown off your part and sucked over toward the anode.   
The iron ions are not going to want to go anywhere, because they're  
positive and they're connected to the negative side of your circuit.

But if you want to CREATE rust on your part, hook your part to the  
positive side of your power supply and your cathode to the negative.   
Your part will now attract all the stray oxygen ions over to it,  
creating a coating of rust.

I'm sure this is overly simplistic and technically flawed, but it's a  
good way to look at it so you don't hook up your circuit backwards.

Rob