Took another look at the underside of the hatch that I paint-stripped yesterday. I rubbed back the etch primer and tried to get a smooth finish. The problem is that where there is paint remaining which did not come off with the Nitromors, then it is very hard to rub back. On reflection I think it would be better to repeat the Nitormors application again to remove all traces of paint. It is certainly not worth trying to bodge by partly stripping and then attempting to hide the rubbish finish with building up primer!