In article , Tim Auton
wrote:

Ernie Leimkuhler wrote:
[pickling]
I use Electro-passivation.
I apply the citrisurf with a wand that is connected to one side of a 36
volt DC power source.
The other side is grounded to the piece.
The paste carries the electrical current which catalizes the citric
acid.
It is extremely fast and very non-toxic.

Can you describe the wand? Is it just a metal rod or does it have a
conductive (carbon?) brush? (I mean brush in the paint, rather than DC
motor, sense)


Tim

The wand is a 7 inch long piece of 1/4" copper tube.
The last 1-1/2 inches on one end is hammered flat, making a paddle
shape about 1/2 inch wide and 1-1/2 inch long.
The remaining round tube section is sheathed in a 5 inch length of
acrylic tubing to act as an insulator.
The electrical wire is slid into the round end of the tube and swaged
in.

A piece of coarse scotchbrite pad measuring 1 inch x 4 inches is
wrapped around the end of the paddle and held in place with a small
plastic ziptie.

To use you dip the scotchbrite pad into the citrisurf solution and
scrub the weld area with the piece grounded.

It works very fast.