The land where I'll be using this compactor is very sandy. The pond area has marginal clay mix. It held water reasonable well before the original dam broke and it was never compacted during the original construction so I'm hoping as I reconstruct the dam and deepen the pond using the compactor will help things out a little more.
I guess if you do have clay the compactor would help, but I would think the water dissolving the loose fill would settle it more than the compactor would (unless like you said there is enough clay to get things to bind up)
Good luck. I wonder how much it would cost to rent a much bigger compactor vs building your own "light one"
Either way, building things is always half the fun