Thanks Ted. As you can see, the billboard came off the barrel also but that took a little longer. I got all the supplies from
www.supergrit.com in Gettysburg. I used some gray, 300 grit compound on a buffing wheel, some 1,000 and 2,500 grit silicon carbide paper and some green polishing compound. The white compound is for aluminum and brass so it won't do too much more than the green does. The buffing wheel must spin fast and my grinder isn't rated for wheels less that 3,500 rpm so that should give you an idea how fast it spins. After smoothing out all the high spots, I load a new cloth wheel up with the green compound and start buffing. Including the time it took to remove the billboard, the total time investment was two hours. Hope this helps.
Next project in the making