>I have been wondering if aladyneing the surface might help.  Annodizing
kinda
>gives the surface a rough texture from what I have seen and you can't use
that
>on a head (must be smooth).  However aladyning (which is done on aircraft

Anodize or thick anodize (hardcoat) is as smooth as the subsurface, glossy
smooth on most of our rocket motor parts.  Alodine I use on T4 cases and
indeed is merely a chemical conversion coating.  I don't know, alodine does
not have a great rep for long term corrosion stabilization actually, hence
our use of anodize or hardcoat (very hard makes aluminum surface  Rockwell C
50+) at work.  As for van use, I don't know but I wonder.  Some people were
using a thermal barrier coat on T4 heads with sucess I believe, a ceramic
based thing, HiTemco perhaps.  Who knows, wondering if anyone has tried.

John
vwbus@mindspring.com

Gee BTW want to talk about a well worn thread, we've been here before about
1 billion times since the list started, still no answers.