Snap, crackle, pop goes the 4" cast iron pipe

So I decided that I didn't want to have a nasty old piece of rusty cast iron sticking through my beautiful new metal roof. (This may seem bizarre, and it probably is, but when I get an urge to tear something apart, there's nothing really to stop me.)

I thought to myself: "Hey, you cut through that 2" cast iron pipe in about 15 minutes, so it should only take an hour to cut through a 4" pipe." And then I wondered why I thought the word "only," and set out to find a better solution.

This is the answer:

A snap chain cutter. It's a giant, heavy tool whose sole purpose is to clamp down really hard on a pipe with a very thick chain that has circular carbide teeth contained in it. And you know what? It works really well.

I hear tell of something similar with a ratchet action, which would probably be even better. The snap chain cutter required two people, and I think it's not really designed for use on pipes that are vertical, because one of the levers has a flat spot on it, probably for putting a foot on top of while it's on the ground. Still, Jacob helped me make 3 cuts in my stack pipe in about a half hour, and most of that time was spent hyperventilating after coordinating our strenuous effort to clamp the jaws together as we gradually increased the tension adjustment.

It's a great tool because it's elegant in its simplicity, and it just plain old works. I rented it for $15 for the day.

Here's the new PVC installed: