[SEL] bolt/fastener finishes

[John Culp]

I quite accidentally found that if you dissolve steel wool in muriatic 
acid till it quits bubbling and leaves an excess of steel wool, making 
a pretty green solution of ferrous chloride, and touch this solution to 
bright zinc plated bolts, they will almost instantly turn a deep black. 
Rinse them quickly as the iron chloride is very corrosive if left.

John

On Jul 9, 2008, at 7:59 AM, bill at antique-engines.com wrote:

> I've got a project going that has bolts, nuts and washers that aren't
> "zinc" or "galvanized". They are black. Best I can tell is they are 
> zinc
> phosphate (not phosphate and oil)
> They actually held up as well as if not better than the silver plated
> bolts and nuts in the same areas.
> I'd like to get the SAME look - the flat black of the zinc-phosphate 
> and
> not use the silver/zinc plated bolts.
> Some are special - flange nuts, thick washers, etc.
> Is there a way I can do this at home?


John Culp
Bristol, Tennessee, USA