Im sanding then spraying my car with primer

Im doing 2 cars at different times, so im curious how much / what i need?

thank you.

 

omg really?? sand paper and primer hardner and reducer. do 1 car first then see how much you need then you will know for the next. maybe a quart get through 1 car and into the 2nd depends on how you spray and cover

 

Well i know how much sand paper im just curious on how much primer would work, Would a gallon do both cars?