Fill material for extruded aluminium

[JImmyhackers]

my lathe and mill are emco/unimat copies.

they are mainly made from hollow extruded aluminum.

just wondered what materials i could fill it with to add some mass and regidity?

 

[Inferno]

Epoxy?

 

[Firstram]

Epoxy?

Ditto, read up on epoxy granite.