The roof is prepared by rolling to shape using a dowel and the top of your thigh. Whilst listening to some music or the afternoon play on Radio 4, press each of the dimples on the underside of the roof to form a neat rivet in the band above. Because of the tight tolerances, some of the dimples coincide with the etched area on the top surface. When soldering the ribs, most of these holes will fill with solder, or later when you paint the roof they will vanish. The ribs are set in a jig so as to get the correct spacing, and the roof is positioned over them. This is now turned upside down and the ribs are soldered, start in the middle of the rib, tack the ends and repeat for each rib. Â Remove the jig and complete the soldering of each rib. Â Solder paint is very useful for this job.