M_Boats: mast question

Any advice on mounting a cast aluminum tang for a forestay to my aluminum mast. A friend of mine says he always uses stainless steel machine screws and taps the holes into the aluminum mast when mounting hardware. I wondered about corrosion with Stainless and aluminum together. Is there any thread compound to use to help with this? What about pop rivets? Are they strong enough? and would I use aluminum or Stainless rivets? Any comments would be appreciated. Jeff