Stainless bolts and screws is about the only method of securing alum mast
hardware, in my experience. The only exception might be those smaller items
secured with alum rivets.

I have never dealt with an alum. pleasure but but on all US Navy alum. ship
and boats. Stainless bolts are used, however there is always insulators in
the holes and under the fitting.

In outfitting my mast, I used "Lanolin Grease" on the threads of all my
screws and on the faying surface (between the different metals). After 3
years in the water, I haven't noticed any problem with corrosion or siezed
threads.

I might also suggest that when tapping threads in alum., use a oil
especially for this purpose. You can get it at any outfit that speciallizes
in machine shop supplies or from major bolt and screw distributor.


--
My experience and opinion, FWIW
--
Steve
s/v Good Intentions