Am i missing something? I just read a long writeup ([ http://www.twinturbo.net/net/viewmsg.aspx?forum=technical&msg_id=840923&forum=technical&dtSearch=0 ]) on how to polish a plenum and it seems like most of the time is spent removing the rough surface left by casting. Why not just use a grinder with a sandpaper wheel? I just tried on the underside and it seems to take the finish down to fresh aluminum without a problem really quickly. has anyone tried this approach? is there any reason not to proceed? it seems like i should be able to get the wheel to 95% of the surfaces rather easily...
