900F dissolving point of aluminum in zinc from pennies to get Zn-Al alloy that is 80% the strength of mild steel. Simple pot on a stove does it. Takes advantage of low melt temp of zinc.[1]. Takes advantage of higher strength of aluminum and has strength better than aluminum. Zn tensile strength is 30ksi.
This removes the induction furnace from the requirement of melting aluminum for aluminum casting.
Melting point of 900F is 480C. Aluminum is 660C.

Links

Alloy melt temperatures - [2]
Open Source Metallurgy Construction Set
This desktop arc furnace (from a welder, a firebrick, and battery electrodes) can melt pretty much anything (including river rocks). It could be quite easy to scale up a bit

Stovetop Metal Casting