RUST Help!
 

We have a nice looking table and chairs set formerly used under roof. Now we wanted to use it in our new birdcage. It bleeds rusty puddles onto the concrete. This will not be acceptable on the newly painted concrete. Does anyone have ideas on how to stop the rusting? Please and thank you.

Spray it with clear coat to seal it. Maybe clear rustoleum.

I have extensive experience rebuilding old cars (aka lots of rust). There are several automotive products that work well. However, if you want the ultimate protection, go to Eastwood - Auto Body Repair Tools | MIG Welder | TIG Welder | Plasma Cutter | Auto Body Supplies & Accessories they have a 2 and 3 step rustproofing system that is great.
Hope this helps, and PM if you need additional help of have other questions.

When the set gets wet, it's as though the water runs out of the hollow legs.

OK, then you will need the Eastwood AUTOMOTIVE FRAME coatings, these are very specific to coating the inside of auto frames. If the design of the table and chairs do not have easy access to the INSIDE of the legs, etc, then access holes may need to be drilled.

If you think you are over your head, send my a PM and I will see if I can help.