So, you're doing finish work on the doors and thinking about blasting or dipping? Kind of putting the cart before the horse. (i'm not trying to be a smart ***, but stripping should be first) Anyhow, I'd strongly suggest having them glass bead blasted by someone with a lot of experience with auto body parts. Glass bead can be shot at a lower PSI, so it creates less heat, therefore reducing chance of warping significantly. Just remember, if you have something dipped, all old paint and protectant will be off- in every nook and cranny that you won't be able to get your paint gun in to.
