A friend is looking at a car that was Media Blasted than left outside for over a year.
Needless to say it has a lot of rust. I thought I read here that a chemical could be used to
disolve the rust than prime the car. or is it to late does the car need to be blasted again and then
primed. Any ideas anyone else have the same situation ?

If light surface rust, you can either: convert it (RustMort, Ospho), remove it chemically (Naval Jelly), sand it off, or media blast it. I think I'd just take a DA with some 80 or 150 if the rust is just on the surface. Then degrease it and get it in a coat of epoxy unless filler is needed in some areas. Or if not ready for bodywork at least spray it in epoxy, then sand down areas to bare metal needing filler when ready.

get about ten kiddy pools and tie them all together, making a super big vat. Dump in about 500gallons of POR15 and stir slightly. GEt some buds to help dunk the car in there w/ some spare ropes and pulleys. Hang dry and get some sort of great big cap w/ alot of saran wrap to seal up the large vat so it doesnt dry out over nite.