Re: Tires as Fenders
I'm also often frugal, but this isn't the right place to be frugal.
I spent 5 minutes buffing tire marks off of my friends boat yesterday after we hit a dock-mounted tire while docking in high winds. If you don't mind your boat being covered in black skid marks then they work fine, but if nothing else you'll be paying for it later in buffing compound and wax.
Used fenders are about the same price as used tires. I was offered two free ones on Sunday by one of my dock mates. Even at local used sailing stores you can get them for about $10/ea.
boats that I sail on regularly: Pearson 28-2, Rondar 505, Yankee 30, Blanchard Junior