that sounds like the kind they used to do in my grandfathers time in Russia. it was old oil and things like axle grease spread around the undercarriage and fender wells and then a lengthy drive thru dust and sand to “seal” and harden it.
yea, i realize that, but the reason I want to do this is preventative. theres no rust on the car in question, so i’d like prevent or prolongue its formation for as long as possible.