Question

What happens with an object when the buoyant force is stronger than the force of gravity?

Answer 1

If the buoyant force is greater than the force of gravity, then the object will keep going up!

http://phet.colorado.edu/sims/density-and-buoyancy/buoyancy_en.html

By using the simulator above, you can see that when buoyant force and gravity are equal, the block floats.

However, if the buoyant force is greater than gravity, the object (example would be a balloon) it will keep going up until it is disturbed or can't any further!