Deadener in the wheel wells

(This isn't a question -- just venting some steam. Though if anyone has any advice, I'm open to it!)

Sweet Jesus. I'm a Catholic priest. If I weren't a religious man already, I would be now.

I'm stripping my 1967 Dodge Dart 270 back to bare metal to prepare for a new coat of paint. The old paint couldn't be salvaged. It wasn't stable enough to hold a new coat. So, armed with a DA sander and a wire brush attachment for my power drill, I got to work a few weeks ago. I've managed to strip back most of the big, flat surfaces. Yesterday, the time came to start attacking the deadener material in the wheel wells and in the rear quarter panels.

Did they use concrete for this stuff? Because it feels like they used concrete for this stuff. The answer has to be "no," though, because it melts under sandpaper.

About the only thing I've found that works is to hack at it with a sharp carpenter's chisel. That shaves most of it off. Then I go in with my sander to clear out the more flat surfaces and finish up with the wire wheel.

Again, sweet Jesus. And I haven't even started on the "nooks and crannies" of the doors. And I haven't even thought about the nightmare that will be the underside of the car.

</rant>