Why is rust so expensive. I saw on eBay
Fe3O4 10 pounds for 25 bucks. Anyone use it as a substitute to GFO. Its the same chemical compound.
Google 10 Lb Black Iron Oxide - Fe3o4 - Magnetic Silly Putty / Pigment
Google 10 Lb Black Iron Oxide - Fe3o4 - Magnetic Silly Putty / Pigment

