Filling in voids in 7x16 mini lathe.

I’ve seen some YouTube videos lately where people have filled in the open spaces of the bed casting with epoxy with filler, I think usually aluminum oxide. I’d like to do this but was wondering if there was some other type of filler that could be used that would be heavier/more dense? I think the idea here is to use just enough epoxy for it to bond to maximize filler weight. How much could carbide turning inserts be crushed up with a 50 ton hydraulic press? I have access to a plethora of chipped/broken/worn ones at work. I’m sure there’s risk of shrapnel in doing this so I would have to put some scrap blocks around the press head or whip up some sheet metal guards. Any other ideas?

I hear epoxy granite is pretty good for machinery bases. It has very high vibration absorption, which is a good thing for equipment bases.

https://www.youtube.com/watch?v=4aBVAbfxLJw

Epoxy granite is the best but concrete does a reasonable job on small lathes at a fraction of the price. Paint over the concrete with epoxy to seal it and prevent grit escaping.

I have used oil and plain dry sifted dirt to fill grinder stands and hollow columns or closed bases on machines as vibration limiting. of course, this will not work for anything that doesn't have sealed voids, and very little initial stiffening. About 15 to 20 % oil to dirt ratio mixed and packed in a column and sealed. Over time the oil is absorbed in the dirt causing it to expand and become hard as stone.