How does electro-polish work?

[BLAMM!!]

We send parts out for electro-polish all the time and I have always wondered how it works. The parts look a milion times shinier after the are done but surface roughness sometimes measures higher on a profilometer. Anyone know what this process is? Are the workpieces submerged in water that is charged?

[Geof]

Here is a link with some explanation.

http://www.ableelectropolishing.com/electrop.htm

Electropolishing is the reverse of electroplating; material is electrochemically removed in a bath of electrolyte when a current is passed through. As far as I understand it the polishing effect depends on the chemical make up of the electrolyte, this is a solution of organic and inorganic salts, and on the fact that the electrochemical reaction is fastest at sharp points on the surface of the part. All the sharp corners get rounded off so the surface becomes smooth. But not flat as you have found out.

[BLAMM!!]

wow,... thanks!