Get a friend have him run the pressure washer while you run the sand blaster and save yourself the bucks...
Seriously thats a lot of $. You'd have to do a lot of blasting to recoop the cost of the unit let alone the time invested in all the blasting. Going into business? Live in an area that stops you from doing regular blasting for environmental reasons?
Have you considered that after regular blasting your metal is primer ready... but after this process you'll have wet metal and soggy sand filling all your seams? So now you have the extra step of drying and cleaning out the seems too. But thats just more labor so no worries there... surely the threat of new rust developing wouldn't be of concern, would it?
