I have used POR Glisten on most of the polished aly parts on my GT40 & have been seriously impressed. At first, I was dubious about the "hammer tough" claims, so I did a test - cleaned up a test piece & brushed some Glisten on. I left it for 3 days then whacked into in with a ball-peen hammer - all I got was dents - no cracking / peeling / etc !
I found that the best way to apply it is is one rather generous coat (everey time I tried the recommended 2nd coat, I had brush marks). With one solid coat (using 5-10% POR thinners), the self levelling capability is amazing. BUT, you must follow the recommended cleaning process with the right POR products beforehand.
I'll be using this for all the alloy/aly bits on the Vette - it looks better than silver ceramic coating, & is way cheaper & easier.
BTW, don't bother trying to use it on mild steel - looks good for a while, but then you get rust steaks.
Kind Regards,
Peter D.