Mark, If you are gonna store the car inside while you are working on it, I think you could just put spray bomb primer on the bare metal to fend off the rust while you're doing repairs. You might also want to use a weld through type primer like the 3M brand. I use it and it seems to work. If the car will be exposed to weather while it's being worked on, I would use a good rust treatment on the bare metal and then spray the areas with two-part epoxy primer. You'll have to remove the epoxy from your active work areas to do any more welding, but at least you won't be causing more damage by letting rust take over. Just my opinions but you asked. Regards, Joe Fulton