Aluminium foil Aluminium foil Aluminium foil (or aluminum foil), often referred to with the misnomer tin foil, is aluminium prepared in thin metal leaves with a thickness less than ; thinner gauges down to are also commonly used. In the United States, foils are commonly gauged in thousandths of an inch or mils. Standard household foil is typically thick, and heavy duty household foil is typically . The foil is pliable, and can be readily bent or wrapped around objects. Thin foils are fragile and are sometimes laminated to other materials such as plastics or paper to make them more useful. Aluminium
Bruce foil a downwards force. Bruce foils can be mounted in pairs, one on each side, as used in some trimaran designs. In this case, the leeward foil works in conjunction with the leeward ama to provide lift, and the windward foil can be retracted to reduce drag. At equilibrium, the force from the foil and the sail will always be balanced, so capsize should be impossible, but in practice that is not the case. Since the foil's force is relative to the hull's movement through the water, and the sail's force is relative to the wind moving past the sail, sudden