Above: The chrome is forced up by the corrosion on the aluminium shell and being brittle, snaps off in small flakes.
Above: The chrome peels off in large lumps in really bad cases!
The example below wasn't much better and was the one that I restored.
Above: the project drum as bought... missing 2 lugs, 4 rods, top head and still fitted with a broken bottom head... the shell was badly pitted and the hoops were rusty. The only thing it had going for it at the time was it was inexpensive to buy!
I wanted to see how cheaply I could tidy up a supra and the finish you see cost about £10 ($15). I sanded the pits smooth, gently feathered the edges back to good chrome and keyed up everything else that was left stuck on (with a heavy duty fine grade sanding disc in a high speed drill), the idea being that if after 35 years what's left after the sanding is still sticking it'll stick even longer with corrosion resistant paint over it. I used special metals primer that can cope with chrome and aluminium as the base coat and corrosion resistant silver hammered paint as the top coat. It was easy to do and the result looks a lot smarter than corroded chrome. Although the most inexpensive method painting isn't sonically the best route so I'll turn to that next.