Removing paint from metal?

I've owned my house for just under 4 years now. I got a decent deal. It's a nearly 40 year old townhouse, and it's kind of small but it's in a beautiful part of New Hampshire and it's big enough for my small family.

The previous owner, though, was a fucking idiot. I've noticed over the last 4 years that a lot of the work he did was half-assed. Things like painting over electrical outlets and light switches.

The house has a wood stove on the main floor and the pipe runs up through one of the rooms upstairs. For some reason, Captain Dicknose painted the pipe when he put the house on the market. I know this because it looked nice when we moved in, but over the last 4 years the paint has started flaking off. I went to Home Depot and picked up a wire brush and paint thinner to take all the paint off and get it down to metal. I'd rather have a shiny metal pipe than a flaky one.

Around where the paint has already started flaking, I can get most of this crap off by scraping at it. The paint thinner is useless and even the wire brush is less effective than I hoped. Some parts of the pipe, though, are really stubborn and that paint isn't going anywhere.

The following images are after an hour of scraping and scrubbing:

On the left side of the second picture you can see where I scrubbed with the wire brush for 20 minutes.

If I keep doing what I've been doing, it will take many hours and I still won't be able to get all this crap off the pipe. Anybody have recommendations? I'm tempted to just replace the whole stupid pipe.