If you're looking at reskinning your bus or doing a roof raise, I just want to help you out by saying that not all air hammers are created equal.
Obviously you can pay more to get more. But I did like several people had mentioned and bought the "Harbor Freight Air Hammer" for removing my rivets. My local Harbor Freight only carried one air hammer, and at >$15, I thought I was getting away with a steal.
Boy was I wrong.
I went and removed all of the rivets in the bus for my roof raise, from the ceiling panels, to the rub rails, to the skin metal, etc. And I did it all with that cheap-o air hammer. It was a pain, and took probably 8 days of air hammering to get those removed. If I got to a big solid rivet, I had to use the angle grinder to get it off.
Then, when it came time to install the rivets, I purchased a "rivet hammer", from Central Pneumatic that was really nothing but a glorified air hammer. The same chisels that I had used with the $15 Harbor Freight even fit (.401 shank).
Well, I found 2 of the largest rivets on the bus that I could test it on.
It peeled those rivet heads off in seconds!!! These are rivets that my $15 cheapo would have taken over a minute to cut through (without considering waiting for my air compressor to refill) if my hammer was freshly sharpened.
They sell these Chicago Pneumatic (Not to be mistaken for Harbor Freight's knock off Central
Pnumatic)ones for ~$50 on amazon. Alternatively, I saw that Harbor Freight carries a more expensive one ($99 without discount) that YouTube says is even stronger than the Chicago Pneumatic.
I wish someone had mentioned that earlier to me.
Links to what I talked about
$99 Harbor Freight
$15 Harbor Freight Air Hammer I used
$57 Chicago Pneumatic CP7150 Air Hammer that I bought for installing my rivets
Note: I haven't successfully installed rivets yet. Still waiting on a proper bit for the rivets to come in the mail.