there are many different views on blasting vehicles for paint prep,I am and have been in the media blasting buisness for close to twenty years now, and have blasted most everything you could imagine as well as used many different medias.soda blasting is a good way to clean body parts but extremely expensive and the soda must be neutralized afterward with chemicals as it is corrosive,walnut shell is not abrasive enough to remove rust and some paints,60 grit or finer silica sand works very well in the hands of an experienced blaster.Ed,it is not heat that causes distortion of the metal as most people think,it is the peening action of the media that compresses the metal,making it harder and dense causing it to expand outward,thus warping it.Think of a ball of dough,as you press on it,it becomes flatter and thinner but gets bigger as it gets flatter,the same happens to metal when blasted,a guy who knows his stuff can keep the nozzle far enough away to take the paint and rust off without peening the metal enough to distort.always hand sand the parts afterward to remove any sand particles that become embedded in the metal,you cant see them after blasting but they will show up in the paint if you dont,and always coat with epoxy primer as metal that has been blasted becomes more porous and is vey suceptible to rust if not treated properly.If a car body is completely stripped I usually blast them inside and out for around $500.hope this helps guys.my truck was blasted,even the rear fenders which are fiberglass were blasted with 80 grit silica.
