I feel like I pull the head off too much to want to deal with cleaning any goo or making something.
Polishing the head and cylinder was one of the “mods” I did. It worked so well, I’ve never considered anything else.
I have only had aluminum engines. Maybe cast iron won’t mate up as intimately as aluminum and thus require a soft metal in between?
To the point of the thread, it is an excellent way to make a nice application. I’d be happy to use it when I meet the situation that calls for it. It’s just that my moped engines come apart too often and seal too well without it.