1974 Dart Swinger VS. The Evils Of Rust!

Here is what the car looks like after about 5 days of sanding with 80 grit. The top is almost down to bare rust/metal. It's pitted pretty bad in spots but there is no rust through except for a few small spots in the pillars that will have to be fixed. I'm going to post this question in the body/interior/trim section where it will get more exposure, but what do you guys think about rust converters? It looks like it would be my only option for the rust on the roof that I can't sand off, but I don't know if I trust it...