I mull my own sand according to the Original Petrobond formula using Petrobond oil and P1 catalyst .  A nice uniform oil bonded sand that provides superb green strength and a quality finish to your poured metals PetroBond sand is an oil bonded pre-mixed foundry sand made up of fine sharp silica sand and oil. It is used for casting all types of metals. its an oil bonded sand that replaces water bonded sand for metal casting. It doesn't require close attention to moisture content. It is safer too because it doesn't generate potentially explosive amounts of steam. Oil bonded sand can also produce a finer surface finish than water based sand due to its smooth texture and lack of steam generation. It is easier for the novice to use and obtain professional results. it molds just like water based sand. You can use the same tools, patterns and techniques