[Burnt]

Any dumpster diving suggestions on where to get cheap (read: free) coroplast for a jobless grad student currently living below the official poverty level?

I'm going to be testing upper blocks on my cobalt.....probably start with duct tape and move on from there; but i'd like to obtain some coroplast/coroplast substitute from somewhere....either free or cheap....do home improvement stores sell it? hobby stores? I'd prefer not to buy it online