Cast late at night in garage.
Or on weekends late at night in garage.
Don't light up the whole garage.
Use task lighting to only lite up area where casting and use a few sheets of 4×8 1/4 inch plywood standing up to block direct line of sight to the street.
Set a box fan blowing out a side window with air intake from under garage door raised six inches.
A range hood with fan blowing out a side window over a work bench for casting apparatus.
Mate shouldn't object to that one.
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