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 changes in wind speed or direction can unbalance the foil and cause heeling. In addition, a foil on the windward side presents an unstable situation, since any lifting of the foil out of the water, by mechanisms such as heeling or wave action, will result in reduced downwards force, potentially leading to capsize. A lee foil provides more stability, as loss of lift will force the foil back into the water. The main advantages over a typical centerboard or leeboard is that the Bruce foil allows the sails to remain nearly upright and keep the full force of the wind