brings back many memories of my apprenticeship years
we had 6 base exchange furnace's ( blast furnace ) also we had a large number of casting shops with an associated cupola we did green sand casting to 50 ton co2 set to 5 ton resin set for small stuff ie nuts and bolts spanners accurate to 3 thou the nuts and bolts would screw together without machining the later stuff was ductile iron
we also did spun pipes to 48 inches 18 foot long, but for old pipe repairs we still had the old pipe pits for special orders
I used to slip in the odd cope in now and again
nice to se it done on a small scale
best of luck with future casting and dont let the iron see sunlight ( old casters moto )
btw I was not a moulder but a sparks
Stuart