A method of attaching a projection to a thin walled component, the thin walled component having a first surface and an opposite second surface, the method comprises the steps of: (i) providing a thin walled component; (ii) identifying a first position on the first surface of the thin walled component; (iii) building a hollow thin walled lattice structure on the second surface at a second position using a liquid metal deposition process, the second position corresponding to the first position; and (iv) building a projection on the first surface at the first position using a liquid metal deposition process.