If i were in space, and had i gl sphere filled with water maybe the size of a basketball?

an if i could then introduce a small metal ball the size of.. a baseball or tennis ball. Do you think the metal ball fix to the center of the entire object in question or float freely in the water. If it were to fix itself to the center, then i introduce small metal filings, like a sand made up of tiny grains of metal. would they then settle in the middle on the metal ball. In my mind i imagine they would, This would illustrate space time and matter, water being the spacetime, an the metal being the matter. The metal warping the water around it. Also i imagine this would only work if the ball was pressurized because it would need a force to to be acting on it constantly for elements to separate, e.g. gravity separates heavy elements from lighter elements, if i were in a spaceship then i would have my pressure.