Dave, here is one place you can buy it by the rail car:
Malt Products Corporation - Molasses, Malt Extract, Organic Malt, Agave Syrup, Specialty Sweeteners, Invert Syrups
Pete, I have been reading about molasses and have read several times that it is used for a binder in morter. I am going to a horse stable and inquiry about borrowing some of the molasses. I wonder if the sulfer content is a factor in the rust removal?