I own a 1916 farm house with a tin/metal roof. What is the best paint/sealant to apply to the roof to keep it from rusting? I've seen the aluminum paint that is used on mobile home's. Will this work on my roof? Do you put it on with a roof mop or a standard paint roller? Do you need to caulk each joint or does the paint have enough fibers to seal the joints? How long will the sealant last? I live in Richmond, VA so the winters are not that harsh. Any help will be appreciated. Thanks.