I have surface rust on the roof of my splitty and were wondering what is the best way to remove it without damaging or warping the panels. It is quite severe in terms of surface rust and virtually covers the whole roof so I were hoping for some sought of mechanical means. What do panelbeaters/painters do?
Thanks Nicko

You can use clean 'n' strip wheels

There are ones now you can get that are able to be put on an angle grinder. If you can get yourself a variable speed angle grinder, that will be the best way.

Also after it has mechanically been removed, a phosphate based rust removing acid is the next step. It will eat into the remaining stains and also condition the surface of the metal.

Sia strip discs

http://www.sia-abrasives.com/fibral/en/89E7CE71A9394D11840AD80ABC2B17FD.html 

Septone Phosphoric acid

http://www.septone.com.au/detail.asp?item_cat=11&item_number=357&page_num=1 

Thanks Helbus Would you go for a 4 inch angle grinder or larger or would a buffer be any use.
Nicko

A 4 inch angle grinder will do it

I had to sand blast my roof.