Foil (metal) Foil (metal) A foil is a very thin sheet of metal, usually made by hammering or rolling. Foils are most easily made with malleable metals, such as aluminium, copper, tin, and gold. Foils usually bend under their own weight and can be torn easily. The more malleable a metal, the thinner foil can be made with it. For example, aluminium foil is usually about 1/1000 inch (0.03 mm), whereas gold (more malleable than aluminium) can be made into foil only a few atoms thick, called gold leaf. Extremely thin foil is called metal leaf. Leaf tears very easily and must
Bruce foil available to drive movement without the crew needing to move their weight. The main disadvantage is that the sails remain upright and keep the full force of the wind available, rather than depowering with increasing angle of heel as happens with traditional foils. The Bruce foil also produces increased drag as a result of the vertical component of force, as well as a yawing force due to the off-center placement of the foil, which may require alteration of the steering system to compensate. Bruce foil A Bruce foil is a variant of the leeboard, consisting of a foil typically mounted