I worked in an industry that machined large pieces (relative to me) all the time, Their product was a cast iron frame and cylinders with steel cranks and con rods. The largest con rods were larger than my forearm and too heavy to lift. The smallest cranks had 2 1/2" mains. The largest cylinders took pistons over 30 inches in diameter. CI machines much more easily than steel. the chips can be vacuumed easily, they're dust. Yeah, you want to have a dust collector going along side your cutter. We didn't consider it to be bad working conditions. Another job I had, the only product of the factory was CI brake rotors. same working conditions. Except all operations were flooded with coolant.
I have no prejudice against CI. It's good stable material.
Its dirty, but there is something primal about it; iron and humanity have a common thread about us. I have pleasure in working it; I think that I am communing with many generations of antecedents; we are iron, it flows through our veins and arteries; we are it!
My wife suffers from AMD, it's a problem with the retina, there is no cure and it eventually results in the loss of the central visual field. Current treatment consists of monthly injections in both eyeballs.
One of the few cases where being stuck in the eye is better than the alternative.
Gray cast or modular iron, no problem. Just clean up well afterward. White cast has iron carbide inclusions which eat cutting tools. It's a bummer when drilling or tapping to hit one of those.
I found found it to be a good idea when tapping C.I. to back the tap out and clean the flutes frequently. The small chips will pack the flutes and can jam up when backing the tap out causing some anxious moments.
Used to machine cast iron regularly for my job on a horizontal boring mill. I don't understand what the fuss is all about. Yeah, it's dusty and dirty but cuts like butter. It's just another trade off. For tapping, use a spiral flute gun tap. I never used coolant on cast iron, all cuts were dry. I bored a lot of holes then pressed bronze bushings in and bored those too.
At one time I ran so much cast iron I sweat rust for months after getting another job. Ya tasted it with every mouth full of food at lunch even after washing and showering up. Took me a couple years after to be free of rust I think . I really like machining it but I did ruin bits with hard spots in it. So even tho it's dirty I like it.
Sash weights were mostly made out of what remained in the "pot" after all the molds were poured, literally "the bottom of the pot" it did not matter what the pour was, what the metal was suited for, how much slag it might contain, it was used to prevent waste of metal, and no need to go into the "rattler" to remove the burnt on "skin" and the chilled iron can take the edge right off most tools.
The iron that I've machined, has never had hard spots or inclusions, being cast by reputable foundries, I especially like to machine nodular iron, it has the strength of steel, but even in high strength formulations, machines easily. When I was building my compound steam launch engines, I had the two throw crankshafts made of 100-70-03 nodular iron, it has a 100,000 psi tensile strength, but still machines nicely and easily; I look forward to machining iron, and use Boraxo to wash it off me.
What's worse than cast iron? Stringy chips on aluminum or steel or any type of machining on 304 stainless. Overall, I don't have any issues with ci, it doesn't need coolant and the chips clean up easy with a shop vac. Only problems come if you hit a hard spot.