EZGO Shuttle 11 passenger 36volt - rust on frame

[itmajors]

Hello everyone... I am new to the site and to golf carts...

I got a 94 EZGO Shuttle Limo Cart... And it has some rust on the frame looks like it is surface rust and I would like to take care of it... My question is can I tip the golf cart over using an old inflatable mattress as support while I work on it... Since the batteries have the plastic caps can they be left inside the cart on its side for a couple of hours while I work on it? They are new batteries less than 6 months old...

Also can wire brush the frame and use the rubber undercoat spray sold at the auto parts store or there is something better to use on the frame?

Thanks