"Martin H. Eastburn" wrote in message
...
HCl in a tank, with some water to make it higher volume and when steel
is nice and gray - the rust floats off if brushed (with rubber gloves)
and then slide whatever into a large tank of Baking soda with soda sitting
on the bottom - to replace what is used up.

Steel comes out nice gray/steel color. Without baking soda the steel
will rust.

This takes off Black Scale from hot rolled and rust.

Martin - been doing it all week.

A word of caution. If you pickle heat treated objects, they should receive
a roast afterwards to eliminate hydrogen embrittlement.

Harold