Component-based development has emerged as an effective approach to building flexible systems, but there is little experience in applying this approach to Grid programming. This paper presents our experience with reengineering a high performance numerical solver to become a component-based Grid application. The adopted component model is an extension of the generic Fractal model that specifically targets grid environments. The paper provides qualitative and quantitative evidence that componentisation has improved the modifiability and reusability of the application while not significantly affecting performance.