[Milsurplus] Satin finishing aluminum

[Al Klase]

jhaynes@alumni.uark.edu wrote:

> The yellowish aluminum seen in a lot of military stuff is the result
> of a "chromate conversion coating" but I don't know any more about it.
> 
 
Yes, sodium hydroxide will get you a satin finish, but
that's the easy part.  For long life some kind of protective
finish is required.  Most commercial stuff gets a
"conversion coating" of some sort.  I was involve with this
years ago.  After the etch and rinse the work is dunked in a
second solution and rinsed again. This prevents corrosion
and finget printing etc.  There are clear ones as well as
the yellow mentioned above.  Two trade names I know of are
"Alodyne" and "Clear Coat."
The $64 question is where to get the chemicals in small
quantities.

Regards,
Al


-- 
Al Klase - N3FRQ
skywaves@bw.webex.net
Flemington, NJ 08822
Web Page:  http://www.webex.net/~skywaves/home.htm