So after about 20 hours, I've got the underside as bare as I'm going to get it. The question now is whether or not I do the entire body, then send it to the blaster company to get it to 100 percent bare metal and then prime it myself. Still on the fence on this. Anyway, I'm pretty psyched to have this part done and for the sake of a few grinding discs, I'm pretty happy with the result. And I'm still shocked at how rust free this car is!