I don't think you need to sand. I believe you can use a wire brush to remove any loose particles, then spray with a primer before painting your final color.

Although I saw one at Lowe's, floor model, on sale for $78.

We have a very nice patio table which is rusting. It is one of those metal mesh kind. Is it worth sanding and reprinting? Or should we free cycle and buy new?

http://www.target.com/p/hamlake-wrought-iron-round-patio-dining-table/-/A-15546679