<P> In the 1970s, designers adapted their yacht designs to the then very popular backyard building scheme of building a boat using ferrocement . Its big attraction was that for minimum outlay and costs, a reasonable application of skill, an amateur could construct a smooth, strong and substantial yacht hull . A ferro - cement hull can prove to be of similar or lower weight than a fiber reinforced plastic (fiberglass), aluminum, or steel hull . New methods of laminating layers of cement and steel mesh in a mold may bring new life to ferro - cement boat - building . A thorough examination of reinforced concrete and current practice would benefit the boat builder . An example of a well known ferro - cement boat is Hardiesse, the Falmouth sail - training ship . </P> <P> There are basically three types of methods of ferrocement . They are following </P> <Ol> <Li> Armature system: In this method the skeleton steel is welded to the desired shape on either of sides of which are tied several layers of stretched meshes . This is strong enough, so that mortar can be filled in by pressing for one side and temporarily supporting from the other side . Filling in of mortar can also be administered by pressing in the mortar from both the sides . In this method the skeletal steel (bars) are at centre of the section and as such they add to the dead weight of without any contribution to strength . </Li> <Li> Closed mould systems: Several layers of meshes are tied together against the surface of the mould which holds them in position while mortar is being filled in . The mould may be removed after curing or may remain in position as a permanent part of a finished structure . If the mould is to be removed for reuse, releasing agent must be used . </Li> <Li> Integrated mould system: Using minimum reinforcement any integral mould is first to be considered to act as a framework . On this mould layers of meshes are fixed on either side and plastering is done onto them from both sides . As the name suggests, the mould remains permanently as an integral part of the finished structure . (e.g. double T - sections for flooring, roofing etc .) Precaution should be taken to have firm connection between the mould and the layers filled in later, so that finished product as a whole integral structural unit . </Li> </Ol> <Li> Armature system: In this method the skeleton steel is welded to the desired shape on either of sides of which are tied several layers of stretched meshes . This is strong enough, so that mortar can be filled in by pressing for one side and temporarily supporting from the other side . Filling in of mortar can also be administered by pressing in the mortar from both the sides . In this method the skeletal steel (bars) are at centre of the section and as such they add to the dead weight of without any contribution to strength . </Li>

How many methods of ferro cementing are there
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