larry wrote:

You don't mention how "clean" your part is. Are you taking off the
Clad coating? If so, the parts really need to remain *submerged* until
coating. Any exposure to air will instantly start oxidation and reduce
coverage quality (usually judged, as you're doing, by depth of color).

My theory is that your initial coating, utilitzing your stated process,
is merely adhering to an oxidation layer that, of course, scrubs right
off. The most of the surface was "sealed", if you will, against
further oxidation and once re-treated, responded in a more predictable
and acceptable manner. Just a guess.



Larry

Can you explain what you mean by Clad coating?