Rapid prototyping systems are based, almost exclusively on polymer, or paper materials. The dimensions of the parts produced are limited by the volume of the processing area within the machine, and parts tend to warp or distort due to shrinkage and lack of support. Also the mechanical properties of the part are restricted to those of the processable materials and thus, in many cases, required 'engineering properties' cannot be obtained. Various European organisations are undertaking research to produce metal prototypes directly, for example, one project is concerned with a version of Laminated Object Manufacturing where sheets of steel are laser welded together. There are also a number of organisations using laser sintering to produce parts in Mild Steel and Stainless Steel. At Nottingham, work on Rapid Prototyping systems, based on a 3-D welding system, has been undertaken to try to combat some of the weaknesses of the other processes. There is some history of the use of welding as a means of building up components and parts for salvage and reclamation; thicknesses up to 50mm being typical (1). The use of welding for creating free standing shapes was established in Germany in the 1960's (2). This led to companies such as Krupp, Thyssen and Sulzer developing welding techniques for the fabrication of large components of simple geometry, such as pressure vessels which could weigh up to 500 tonnes (3). The -technique was to become known as 'shape welding'. Other work in this area has been undertaken by Babcock and Wilcox (4) who have been working mainly on large components produced in austenitic material. Also, work by RollsRoyce (5) has centred on investigating the technique as a means of reducing the wastage levels of expensive high performance alloys which can occur in conventional processing. They have successfully produced various aircraft engine parts in Nickel based and titanium based alloys.