[ARC5] WTB: ARC-5 screws

[J Forster]

This is what I referenced:

"Ultra-Blak 420 for Copper/Brass — This black oxide is an oxidizing salt
mixture for
blackening copper, brass and bronze. Used at a concentration of 2 pounds
per gallon of
water at temperatures of 200° to 210° F to blacken copper surfaces with
a deep black,
abrasion resistant finish. It must be used in conjunction with EPI's
E-Prep 220 brass
activator to blacken high zinc (15% to 35% zinc) copper alloyed
surfaces. "

A boiling water bath should do fine, if you don't live on top of Mt.
Everest.

-John



WA5CAB at cs.com wrote:

> Yes, I've seen some of these cold process products.  But the
> commercial or industrial grade process on brass is done at somewhat
> elevated temperature.  The process for iron, steel and stainless steel
> is done at a much higher temperature.  The last place that was doing
> steel here in Houston quit doing it after one of their employees was
> either killed or severely maimed (I can't recall which the owner told
> me).
>
> Note the operating temperatures of up to 285 F for the bulk process
> chemicals.  However, for $400 they do have a room temperature kit.
> But the writeup doesn't discuss how you handle parts into and out of
> the various baths.